Making Medicine Part 5 of 5: Pressing and Filtering a Tincture

This is the fifth and last post in a series in which I am using the process of wild harvesting and making a fresh herb tincture of blue vervain (Verbena hastata) as an example to explain in detail the process of making herbal tinctures. In Part 1 of this series I discussed the process of harvesting blue vervain; in Part 2, preparing the herb for macerating; in Part 3, preparing the maceration; and in Part 4 I discussed some of the common equipment that is available for pressing and filtering the maceration. Now we're going to look at the actual process of pressing and filtering our maceration to prepare the tincture.

As I indicated in Part 4, this final stage in preparing our tincture can be either a single or two part process. The standard method is to pour the maceration into our press. Much of the fluid (also called the macerate) will flow through, but not all of it. Then we apply as much pressure as our press will easily allow to squeeze as much of the fluid as we can out of the herb material (also called the marc). The better the press, the more fluid that we can press out of the herb. This is not only more efficient because we will end up with a greater volume of tincture, but our tincture will tend to be a bit stronger because the fluid that is deep withing the tissues of the herb will tend to contain the highest concentration of its constituents. Having macerated the herb for at least three months will ensure that the herb tissues have softened sufficiently to make it more easier for our menstruum to penetrate into the tissues of the herb, extract its chemical constituents, and be pressed out when we apply pressure.

With this method, the fluid that flows from the press will contain herb particles that are small enough to pass through. The fluid must then be filtered. The standard method is to allow the tincture to flow into a filter in a funnel placed over a large beaker or other kind of receiving container, and allow gravity to draw the tincture through the filter. Beakers are the best container to use because they have a large opening, are graduated, have a spout that will make it easier to pour the tincture into our bottles, and better ones will be made of borosilicate glass which is more durable. Although the graduations on a beaker do not allow us to accurately measure the volume of our tincture, they give us an approximate volume which allows us to determine the size and number of bottles we will need to store it.

For this process we do not want to use a paper filter as these are too fine. We need to use a fairly coarse filter because we want to include the fine sediment and other thick components like latex in our tincture. This means that it is best to use a cloth filter. It is critical that our filter does not contain lots of chemicals that are typically found on fabrics these days. The best fabrics are unbleached organic cotton, hemp or another natural fibre or combination of fibres. Muslin or some other coarse weave is best as long as it isn't fuzzy like flannel. Otherwise cloth fibres might end up in our tincture. Even when using a relatively non-toxic fabric to make our filters, it is best to wash them a few times and rinse them very well. We don't want soap in our tinctures! Cloth filters will last many years. They need to be scrubbed (by rubbing the fabric against itself) and rinsed well after use. Although it is best to use soap the first time we wash them and rinse them very well, water alone is best after their initial use. Soap isn't necessary because tinctures are sterile. However, it is important that the filters be allowed to dry completely before storing them.

When using a potato ricer, the macerate (fluid) and herb material are poured into the ricer, which is held over the filter.

The liquid will flow through into the filter. An cone-shaped unbleached cotton coffee filter works well for this.

The herb material (marc) is then squeezed to get as much liquid out as possible. Once the macerate

has completely flowed through the filter we wring it out to get any remaining fluid out of it.

In terms of funnels, the best funnels have a design that has a spiral cut into them. This reduces the surface contact between the filter and the funnel and allows the fluid to flow out more quickly. These funnels are usually make of glass or polycarbonate (plastic #7). We don't want to use polycarbonate plastic because it contains toxic chemicals that will leach into our tincture. That leaves the glass ones. However, they are very expensive, easily broken, and only marginally speed up the filtering of tinctures that have sediment or latex. Tinctures that don't have these components tend to filter relatively quickly anyway. As a result, I recommend solid plastic funnels. They are inexpensive and easy to obtain. That being said, we only want to use funnels that are made of polyethylene or polypropylene (plastics #1, #2, #4 and #5) as these are not known to contain any chemicals that will leach into our tincture (so far). If the funnel doesn't clearly indicate which type of plastic it is, don't use it.

With a screw press, the receiving cylinders must be removed from the frame of the press in order to

be able to easily empty the contents of our macerating jar into them. It is also important that

the beaker be at a lower level to allow the tincture to flow into it.

The biggest disadvantage of this method of filtering is that it is very slow. In fact, if the tincture contains a lot of sediment and/or latex it can be extremely slow, even with a very coarse filter. This is undesirable because the longer our tincture is exposed to light and especially air, the greater the amount of degradation of its active constituents that will occur. As a result, I always use the second method of filtering the macerate and that is to make cloth filters that fit inside our pressing device. This allows the maceration to be pressed under pressure. It only slightly slows down the pressing process and the end result is a filtered tincture that can be bottled immediately. The reduction in time will significantly reduce the oxidation of the components of our tincture and therefore improve its quality and how long it can be stored before use. With this method it is not necessary to use a funnel unless we are using a potato ricer as our press. With a well designed screw press or hydraulic press the tincture can be directed directly from our press into the beaker.

With a potato ricer the cotton coffee filter is placed inside the ricer. It's still a good idea to use a funnel because the tincture

doesn't flow out of the ricer as neatly as through a hose and the funnel provides a wider area for it to drain into.

Here's the same set-up with a screw press. In this case it's necessary to make filters that fit the inner cylinder

of the screw press as cotton coffee filters are too small and not the right shape.

We pour the fluid into filter and then empty any of the remaining herb material into it as well. There will always be some residue in the jar, so I will pour some of the filtered tincture back into the jar to rinse the last of the herb material out of it. then we fold up the top of the filter so that when we apply pressure to it none of the unfiltered fluid will flow out of the top. With herbs that have a latex or are very mucilaginous, the filter will sometimes clog up preventing the fluid from draining efficiently. If this happens, it is important that there is no excess liquid on top of the herb material in the filter when we press it or it will not be possible to prevent it from flowing unfiltered out of the top of the filter. In this case I lift the filter part way out of the cylinder and rock it back and forth to speed up the rate at which the macerate flows through. Once the level of liquid is below the top of the herb material, it is OK to fold up the filter over top of it and press it. With a potato ricer we simply press it as hard as we can; with a screw press we tighten the screw as tight as we can; with an hydraulic press we pump it as much as we can.

Tightening the screw.

Here's the actual process using my hydraulic press: pouring the macerate and herbs from the jar into the cylinder.

Pumping the press.

With this method, once we finish pressing the herbs the filtering process is also complete and our tincture is ready! We need to get our tincture into bottles as quickly as possible in order to minimize oxidation. It is necessary to use narrow mouthed bottles because they have a smaller air space and it's easier to pour out of them. Once more we want to use amber glass bottles. The bottles I use are called amber metric rounds. The best lids are plastic phenolic caps with a cone-shaped polyethylene liner as these lids seal the best and polyethylene is one of the two kinds of plastic that are suitable for this purpose (the other being polypropylene).

50 ml, 100 ml and 250 ml amber metric rounds. The equivalent in the US is 2, 4 and 8 oz. bottles, which are slightly larger.

It is better to store our tincture in several smaller bottles rather than one large bottle. This will significantly increase the shelf life of our tincture. Every time we open up the bottle and use some of it we are exposing it to more oxygen and increasing the size of the air space in the bottle. The tincture in the bottle we are using will degrade much more rapidly than tincture in a full, unopened bottle. Since I tend to press half or one litre jars, I store my pressed tincture in multiple 250 ml bottles. If you are making smaller quantities for personal use, it is better to store your tincture in 100 ml bottles. Just like with our maceration, these bottles should be stored in the dark. Presumably, the last one we fill won't be completely full. We'll start by using that one and not start another until it is completely finished. In this way each bottle remains undisturbed until we need it. For most herbs, the tincture stored in the dark in an undisturbed full bottle will maintain its potency for about 6 months to a year. However, once we start opening it and using it it's best to use it up within 4-6 months. They don't go bad. They just lose their potency. The timing I have indicated is what is ideal. It doesn't mean you should throw out a tincture if you don't use it all within that time frame. However, I like to do things as ideal as possible, so I usually don't press any more of a specific tincture than I can use within 4-6 months.

Pouring the finished tincture into storage bottles. For demonstration purposes I broke with the tradition of these posts. I did not press
blue vervain herb tincture (Verbena hastata) because I had plenty on hand. Instead I pressed a half litre of blueweed herb tincture
(Echium vulgare) which is from the Borage family and has similar properties as common comfrey herb (Symphytum officinale).

It's important that we label our bottles of tincture. The label should include the name of the herb, the part of the herb used, the potency of the tincture, and the date it was pressed. I always use the same bottles for the same tincture because the bottle picks up the aroma and energy of the herb. You will note from the photo that I use green masking tape for labels because it is relatively water resistant, can be written upon and looks pretty good. Each time I press a tincture I cross out the old date on the bottle labels and write the new one until the label is full. Then I start a new one. This is an efficient way to label them because the same label can be used many times and a quick scan of the label gives me an accurate indication of how much I am using that tincture. This information is important when it's time to harvest that herb in terms of estimating how much I will need for the following year.

So, that finally wraps up this discussion of making tinctures! I hope that you have found it useful. As I promised way back when I posted the first installment of this series, since blue vervain was the common thread, especially in the first three posts, I am providing detailed information on the properties and uses of this herb that is based on my research and experience on the Herbal Resources page of the Living Earth website in the form of a pdf document that you can download (link to pdf file). Enjoy!

Thank you blue vervain!

Making Medicine, Part 4 of 5: Equipment for Pressing and Filtering Tinctures

This is the fourth post in a series in which I am using the process of wild harvesting and making a fresh herb tincture of blue vervain (Verbena hastata) as an example to explain in detail the process of making herbal tinctures.

Part 1 of this series was posted on July 9th, Part 2 on July 15th, and Part 3 on August 22nd of 2012. After that I got busy and forgot about it, except periodically when someone reminded me about it. The truth is, every time it came up I thought about having to find and drag some old equipment out of storage and set up and take a bunch of photos and I put it off and forgot about it. Well, here is the next installment at last!

This was supposed to be the last post in this series, but it keeps growing! Every time I've worked on it I've realized that there is so much info to cover I keep extending it. However, I am confident that the fifth part will be the last.Taken as a whole, this series is one of the three most viewed offerings that I have posted so far. My apologies to those of you who have been patiently waiting for the conclusion.

In the first three posts we got up to the point where we have prepared the maceration of fresh blue vervain herb and it is being stored in the dark for a minimum of three months. As I stated previously, we don't want to press the maceration until we actually need it because the greatest amount of degradation of the active constituents occurs during the pressing process and afterwards. Once we know that we will be needing the tincture of a particular herb that we are macerating, starting about a week before we press it, it's a good idea to shake it vigorously once per day for about 30-60 seconds and then again immediately before we press it. This helps break up the plant material further now that it is much softer from having soaked for awhile and to get some more of the constituents out of the herb and into solution.

In order to prepare our tincture, the final step requires that the maceration be pressed and filtered. Let's begin by discussing pressing. The purpose of pressing the tincture is to squeeze as much liquid as possible out of the macerating plant material, which is technically called the marc. The more intensely we are able to press the plant material, not only do we get more tincture as an end result, we also get a somewhat stronger tincture because the fluid that is deep in the herb will tend to contain the highest concentration of its constituents. There are different kinds of pressing equipment that work to varying degrees. Unfortunately, as we might expect, the better the press the more expensive it is going to be. This means that we need to strike a balance between wanting to use the best equipment that will produce the largest volume and most potent tincture with the cost. In the long run, if we are serious about making tinctures it is preferable to use the best equipment that we can afford.

There are essentially four ways to press a tincture. Many books recommend the simplest method which is to pour the maceration through a few layers of cheese cloth and then wring out as much liquid as possible by hand. This process is so inefficient that, personally, I consider it a waste of time (and herbs). The simplest and most inexpensive method for pressing your maceration is to use a potato ricer. However, the standard cylinder type ricers are not recommended. They are not strong enough for pressing herbs and will break pretty quick. Although they are more expensive, the best ricer is what is usually marketed as a "professional" potato ricer. These have a triangular shape (see photo) and the part that takes most of the pressure is much stronger. Not only will they allow you to use more pressure, they will last much longer.

The standard cylinder ricer (left) is not strong enough for the kind of pressure necessary to press tinctures. The older professional ricer (middle) demonstrates what happens after many years of use. Note how the point with the wire is wrapped around it is bent out of shape. This is the point that takes the stress from all of the pressure. Wrapping wire around this point will increase the life of the ricer by helping to prevent the parts attached to the handle from slipping over the corners of the bar. The newer model with the more solid handle (right) is better because it isn't as hard on our hands when applying pressure. I used to have to use a towel wrapped around the handle of the old one. This isn't necessary with the design of the newer one.

The next best press is the screw press. There are many types available. They are usually used for pressing grapes to make wine or apples for cider. Wooden presses do not work for tinctures. Only stainless steel presses will do. Most of the better ones are made in Italy. However, there are some flaws in the design of many models that I will address. The more of these features that a press has, the better the quality.

Firstly, it is important that the design has an inner straining cylinder with holes that will contain the herb material while allowing the fluid to pass through, and a slightly larger solid outer cylinder with a hole and spout that allows the fluid to flow out. Ideally, the hole should be flush with the bottom of the container. Although most designs don't have it, it is best if the part of the press that the container sits on has some kind of brace that the spout fits into to hold it in position. Otherwise, when the pressure gets fairly high while we are pressing the tincture, the container and the position of the spout will spin. Another important point is that it is not recommended to just let the tincture flow out of the spout into a beaker or other container. It is best to attach a hose so that we can better direct the flow. Most presses don't come with a hose and it is necessary to purchase one. It's important that it fit snugly on the spout. If it isn't tight enough we can add a hose clamp. The material that the hose is made of is also important. We don't want to use PVC or other materials that will leach toxic chemicals into our tincture. A low-density polyethylene hose (LDPE) is probably the only material that is relatively non-toxic.

Another aspect of the design of a screw press that is important is how the metal disc that presses the herb material is attached to the screw on which it is mounted. Because of the tight fit between the disc and the inner cylinder, many companies do not weld the disc to the screw, but attach it loosely so that it can move. This makes it less likely to get jammed in the cylinder during the pressing process if it is slightly misaligned. The problem with this design is that, as the pressure on the herb increases, some of the tincture will seep up through the space between the disc and the screw and come in contact with the screw. This will allow some of the lubricant on the screw, which will be some kind of rancid oil that also contains fine metal dust from friction between the metal parts, to get into our tincture. This can even be a problem with presses for which the disc is attached to the screw because when the herb material is under a relatively high pressure the tincture will often flow out faster than it can seep through the holes in the inner cylinder. When this happens it will flow through the space between the disc and cylinder and over the top of the disc. Once more it could potentially come in contact with the screw unless the part of the disc that is mounted to the screw is relatively deep so that the level of tincture on top of the disc isn't higher than the point at which the disc is attached to the screw. Unfortunately, most screw presses have one or both of these flaws in their design. There is, however, a way around it and that is to insert a wooden disc between the metal disc and the herb. To do this it will be necessary to cut a round disc that fits fairly snugly into the inner cylinder of the press. It should be at least 2 cm (3/4 inch) thick and made from a relatively hard wood with a tight grain. I have found the best choices of wood to be (in descending order) sugar (hard) maple (Acer saccharum), white ash (Fraxinus americana) or American beech (Fagus grandifolia). There are even harder woods from tropical trees, but as these are usually harvested in an unsustainable manner that has a negative impact on tropical rain forests, I don't recommend them.

The purpose of the wooden disc is not only to prevent the metal disc (and the end of the screw if it is loosely attached) from coming in contact with our herb material, but also to help prevent the tincture from coming in contact with the screw by flowing up over the outer edge of the metal disc. The thickness of the wooden disk allows the tincture extra space where it can flow unimpeded through some additional holes in the inner cylinder. A 2 cm disc will usually be adequate, but up to twice that thickness might be a good idea for an extra margin of safety. For presses for which the metal disc is loosely attached to the screw, if we use a wooden disc between the metal disc and the herb material it is necessary to always position it so that the same side of the wooden disc is facing upwards. This is because inevitably the grease and metal dust from the screw will come in contact with the wooden disc and we don't want that side of the disc coming in contact with our herbs or tincture.

Another thing to look for in a screw press is the design of the frame that holds the screw. With most presses the part that holds the screw is attached to the base at two points. If we don't use the press too much this isn't an issue. However, if we use it a lot and really crank it to squeeze as much tincture out of our herbs as possible, I have found that this design isn't strong enough. Eventually it becomes loose at the points where it attaches to the base. The best designs are those where the part that holds the screw attaches to the base at three points. This is far more stable and more durable in the long run.

This older screw press is the standard design. You can see that the upper part of the frame that holds the screw is tilted from long-term use. The handles aren't long enough to easily apply sufficient torque for pressing tinctures. The metal disc isn't securely fastened to the screw so that it can rotate and tilt slightly, but it leaves enough space to allow tincture to flow up between the screw and the disc and come in contact with the grease on the screw. We eventually welded the disc to the screw with one of these, but due to the thinness of the attachment point, tincture was still able to flow around the edges and up over the top of disc and come in contact with the screw. Adding a wooden disc between the metal disc and the herbs was necessary to prevent this.

There are two more aspects of the design of a screw press that are important. The first relates to the handle that we use to turn the screw and put pressure on the herbs. Most of these presses have handles that are too short. The longer the handle the better. Not only is it easier to grip, but it allows us to put more torque on the screw and therefore more pressure on the herbs. The last issue is that it is best if the inner cylinder has a bottom. Some designs have inner cylinders without a full bottom.

In summary, I only recommend stainless steel screw presses with a two cylinder design and a spout on the outer cylinder. It is best to get one that has a capacity of 1-2 litres (approximately 1-2 quarts). In terms of the design issues I mentioned, the first (metal disc attached to screw with a deep attachment point) is the most important, however, it can be compensated for by using a wooden disc between the metal disc and the herbs. The second (three attachment points) is slightly less important, but it becomes more important the more we use the press. The third (long handles) is even less important, but this little detail can make a big difference in terms of ease and efficiency of use. The fourth (inner cylinder has a bottom) isn't that important, but it does make the press a bit easier to work with.

This is the best designed screw press that I have come across. It has three attachment points for greater stability, strength and durability; larger handles making it easier to turn the screw and apply more torque; a brace in the base that holds the spout in position; and a superior design for the disc attachment (see below). Although parts of the frame are made of aluminum, all of the parts that come in contact with the tincture and herbs are stainless steel. It even has holes in the feet so that it can be secured to a counter or piece of wood for greater stability. However, it is important to be able to tilt the press forward to drain the last bit of tincture out of the cylinder. It could be attached to a piece of wood as long as it is not too large, the front is straight, and doesn't extend too far beyond the feet so that it will still be easy to tilt the press forward. The only disadvantage of this design is that the inner cylinder doesn't have a bottom (see the photo of inner cylinders in the discussion of hydraulic presses below). However, this is only a minor issue; the least important of the various design issues that I have discussed.

Here is a closer look at the disc attachment. It allows the disc to spin so that it is less likely to get jammed in the inner cylinder. It also is fairly deep at the attachment point so that any tincture that flows over the surface of the disc will not come in contact with the grease on the screw. If we press the herbs relatively slowly towards the end, the amount of tincture that seeps up between the outer edge of the disc and the inner cylinder is minimal.

There is one modification to the screw press that I highly recommend. I have found that it is best if the herb material doesn't sit in a pool of tincture. This is because when we apply pressure, after a bit of time the herb material seems to settle a bit which causes a slight reduction in the pressure. When that happens, if the herbs are sitting in the tincture they will reabsorb some of it. Therefore it is best if the tincture is able to efficiently flow away from the herbs as soon as it is pressed out. This is one of the reasons why a press design with a spout is absolutely essential. However, because the bottom of the cylinder is horizontal, the last bit of tincture doesn't flow out very fast. To avoid the herb material sitting in a pool of tincture, what I have found works best is to use a wooden disc as described above. This disc is placed inside the outer cylinder before we insert the inner cylinder so that the inner cylinder is resting on the disc and elevated above the bottom of the outer cylinder.

The third major type of press is the hydraulic press. The best hydraulic presses are the electric ones because they can apply the most pressure. However, these tend to have three limitations. Firstly, they tend to be designed for a larger capacity and are not suitable for small quantities of tincture. Secondly, many designs don't have an outer cylinder. This might be OK for pressing grapes, but for many herbs the tincture will spray out in a way that needs to be contained by an outer cylinder. The third limitation of electric hydraulic presses is that they are extremely expensive. I would only recommend an electric hydraulic press for the production of tinctures on a very large scale requiring the pressing of 4-5 litres or more at a time. Even for an herbalist who has a busy practice and produces all of their own tinctures this is not likely to be economical.

As an alternative, there are a number of designs out there that use a manual hydraulic mechanism. Basically they attach an hydraulic bottle jack (which is typically used as a car jack) to some kind of frame. I have seen a number of designs and most of them are examples of enthusiasm more than efficiency. The typical design is to use an hydraulic bottle jack to squeeze herbs between two stainless steel bowls and then pour off the tincture by tilting the "press" (no holes, no spout). I don't recommend any of these. There is only one that I have come across that I recommend and it is the press that I use myself. Although it's not perfect, it is the best press I've ever worked with. I am always experimenting with different kinds of equipment for making tinctures. I have to say that of all of the equipment that I have acquired, the two most important things in terms of efficiency are my mezzaluna (see Part 2) and my hydraulic press.

This is the best manual hydraulic press that I have come across so far. It works very well but has two design flaws. Firstly, it is too top heavy and awkward to work with. I have a lot of experience working with presses and I don't find it too difficult to use, but most of my students have difficulty working with it on their own and need to work in pairs when using this press. The second design flaw is that there are too few holes in the inner cylinder (see below).

 Note the significant difference in the number of holes between the inner cylinder of the hydraulic press (left) and the screw press (right). Even if it had additional columns of holes in between the existing columns with the spacing of the holes half way between the existing holes it would be a significant improvement. I will probably drill them myself at some point. The cylinder on the left includes a cotton filter which is flared at the top so that it easily folds over the top edge when the maceration is being poured in. The wooden disc (centre) is positioned between the outer and inner cylinders so that the inner cylinder sits on top of it. The filter and the disc are both very stained from the tannins in herbs. Note that the inner cylinder of the screw press doesn't have a complete bottom. It is the only design flaw with that particular press, and a minor one at that.

There is one more trick that will significantly improve the efficiency of pressing and filtering. It is best to use a filter inside the press. This allows the maceration to be filtered under pressure. It eliminates the need for a separate filtration step and significantly decreases the amount of time of the whole pressing and filtering process. This is very important, not only in terms of saving time, but because the less time that elapses between when we open the jars containing our maceration and when we seal the finished tincture in a bottle, the less degradation of the active constituents that will occur. That means a better quality tincture. It is best to custom make filters that fit inside the inner cylinder. They should be a little taller than the cylinder and flared at the top so that they can easily be folded over the top of the cylinder when we pour our maceration into the press. Otherwise the filter will collapse as we pour the maceration into it. The filter should be made out of unbleached cotton or some other natural fibre, preferably certified organic. Use a coarse weave because it will filter easier and we actually want the thicker sediments and latexes of the herbs in our tincture. Before making the filters, it is important to wash the fabric several times with natural detergent because fabrics these days tend to be coated in all kinds of toxic chemicals (see Toxic Threads for more information). It is best to add some vinegar to the water as well.

If we don't use a filter in the press, it is necessary to filter the tincture after pressing it. In this case we allow gravity to filter it through a cotton filter placed inside a funnel over a beaker or other receiving container. We position the hose to allow the tincture to flow into the filter from the press. It is necessary to press the maceration more slowly when using this method so we don't overflow the filter.

There are other designs of equipment that can be used for pressing tinctures. Although I would love to, unfortunately it isn't possible for me to purchase and try them all. Most of the presses I have seen online aren't very good, but I suspect there are a few out there that are worth checking out.

This ends my discussion of pressing and filtering equipment. In Part 5, the final post in this series, I will cover the actual process of pressing and filtering our maceration.

Making Medicine, Part 2 of 5: Preparing Blue Vervain to Make a Tincture

This is the second in a series of five posts in which I am using the process of wild harvesting and making a fresh herb tincture of blue vervain (Verbena hastata) as an example to explain in detail the process of making medicine. Part 1 in this series was posted on July 9th.

In my practice I primarily use tinctures made from fresh herbs, so the next step is to use the blue vervain that we harvested to make a tincture. When you make as much tinctures as I do, you appreciate good equipment. I have experimented with a variety of tools over the years and will discuss some of them here. I am also going to use the process of preparing blue vervain tincture as an example to explain some of the important details regarding making tinctures.

The basic idea is that we want to separate the more potent from the less potent parts of the portion of the plant that we harvested, chop it up and put it in a bottle with the appropriate menstruum (pronounced MEN-strew-um: the liquid that we use to absorb and preserve the constituents of the herb). As an herbalist, it is important to me that the way I prepare a tincture is consistent so that I know that the tincture of any particular herb that I make from year to year is very similar in potency. There are factors that affect the potency of the herb, like weather conditions, that I can't control. However, if the weather conditions are particularly incompatible with the requirements of a particular herb in a particular year, I won't harvest that herb. What I can control is how I prepare the tincture. In order to accomplish this, the portion of the plant that I use needs to be consistent as must the amount of herb that I use for any given volume of menstruum.

When using fresh herbs, I recommend a 1:5 potency. This means that 1 g of herb is used for every 5 ml of menstruum. There are herbalists who recommend a higher potency for various reasons. However, I disagree with using a higher potency than 1:5 for fresh herb tinctures. I will do a detailed post explaining why I prepare tinctures the way I do at some point in the future, but the bottom line is that 1:5 fresh herb tinctures work and a higher potency isn't necessary. Also, the greater the potency that we use above 1:5, the greater the amount of herb we end up using in order to get the same results. For reasons related to the chemical characteristics of the constituents of an herb, using twice as much herb doesn't make a tincture that is twice as strong therapeutically. For example, a 1:2.5 potency tincture should be twice as strong as a 1:5 tincture because we are adding the same amount of herb to half as much menstruum (2.5 ml instead of 5 ml). If this were true, then when we use a 1:2.5 tincture we should get the same results using a dosage that is half as much as the dosage we use for a 1:5 tincture. However, it doesn't work out that way. We need to use more than half as much of a 1:2.5 tincture to get the same results. This is because as we add more herb to the same volume of menstruum, at some point the percentage of constituents that actually dissolves in the menstruum starts to drop off. In addition, for most herbs it is physically impossible to get enough herb into a given volume of menstruum above a 1:5 or 1:4 potency. This necessitates methodologies such as grinding the herbs, percolation or macerating tinctures more than once, which are more time and energy intensive, often require the use of expensive equipment, and lead to a greater level of degradation of the constituents of the herb. Therefore higher potencies are unnecessary and wasteful. For home use, you don't need to be as accurate with your measurements as I am recommending here, but the more accurate the better.

The equipment I use for preparing fresh blue vervain tincture.

In preparing a tincture we need to be able to measure the amount of herb that we put into each bottle. For this I use a triple beam balance, but digital scales will do as long as they are calibrated to 1 g increments or smaller. We also need to know how much herb to use per bottle. Traditionally the way we calculate this is to first measure how much fluid the bottles we are using contain when they are filled to 0.5 cm (1/4 inch) from the top. It is necessary to measure this because the volume indicated for the bottle is usually not based on filling it this close to the top. Beakers and measuring cups are not accurate enough for this. It is necessary to use something that is calibrated in 1 ml increments. This usually necessitates the use of a graduated cylinder.

Once we have an accurate read on how much fluid our bottles contain, to approximate how much herb we will need for a 1:5 tincture we divide the total by 6, that is for 1 part herb plus 5 parts menstruum. This is not 100% accurate because herbs are usually less dense than water and not all herbs are of equal density. However, although this is an approximation, it is surprisingly accurate. It is sufficient for most situations. The key is to get as accurate a measurement as possible of the volume of the bottles we are using. I have done extremely detailed calculations for all of the tinctures that I make and, with only a couple of exceptions, this approximation is accurate to within 1-2%, which is good enough.

The harvested portion of one plant.

Once we know how much herb we need per bottle, it is necessary to separate the usable from non-usable parts of the portion of the herb that we harvested. When harvesting the aerial parts of plants (the parts that grow above the ground), this usually means that a portion of the stalk isn't used. This is because the primary purpose of the stalk is to hold up the leaves and flowers. As a result, the stalk tends to contain mostly dense fibrous tissue and a much lower proportion of the therapeutically active constituents. The amount of stalk that has to be removed can be anywhere from 0-100%, depending on the plant and the portion of the plant that is harvested. For most plants from which we harvest the aerial parts we harvest the terminal 25-40%  of the plant and remove 80-90% of the primary stalk and 60-75% of any well-developed secondary stalks. The specifics depend on the species of plant and at what stage we are harvesting it. The portion of the stalk that is usable tends to be the new growth that is less stiff and more succulent. To determine the usable portion for a particular species, we start at the lowest part of the stalk, cut off a small section and taste it. Then cut a similar sized section about 20% further up the stalk, then at 40%, 60%, 80%, and finally the top portion. Finally, we taste a piece of a leaf. The point on the stalk where the flavour of the stalk is about 2/3 to 3/4 as strong as the flavour of the leaf is the point at which the potency of the stalk is strong enough to use. We remove all of the stalk below that point and use all of the stalk above that point. The reason that the taste of the stalk can be used to determine its potency is because its flavour corresponds to the concentration of many of its active chemical constituents. For plants that are relatively bland in flavour because they have little to no aromatic, bitter or pungent constituents, there isn't much difference in the flavour of the different aerial parts of the plant. Therefore we just use the portion of stalk that is less stiff and more succulent.

Blue vervain is unusual in that the flavour of the entire stalk is pretty strong. This is because its flavour is primarily due to chemical constituents called iridoids and the iridoids are in a fairly high concentration in all of the aerial parts of the plant. Nevertheless, for the most part I still only use the less stiff and more succulent parts of the stalk. Overall I remove a little bit less stalk than is typical for most herbs. However, with this herb, if the amount that I harvested is a bit short, I can just use a bit more stalk rather than having to harvest more plants.

The part that is used (above) and the amount of stalk that is not used (below).
This is the same plant that was shown in the previous picture

The next step is removing the unused stalk from all of the plants that we harvested. This can be done with a knife or scissors, but since we tend to cut the stalk at the point where it becomes softer and less fibrous, for most herbs the stalks can be easily torn with our fingers, which takes less time. Once we've separated all of the usable portions of the plants that we harvested, we need to weigh them to make sure that we put the right amount in each bottle. I use four standard sizes of bottles. The blue vervain that I harvested was intended to prepare the largest size, which is a 950 ml bottle. However, the volume of bottles that are narrower at the top than the full width of the bottle are usually calculated to about the top of the shoulder. When the bottles I use are filled to 0.5 cm from the top, they actually hold 990 ml. To determine how much of the usable portion of the herb that we need to use for a bottle this size, we divide 990 by 6 (for a 1:5 tincture), which is 165 g. Although our proportions are made up of 1 part herb, which is measured in grams, and 5 parts menstruum, which is measured in millilitres, this conversion works because the density of menstruum is almost the same as for water. The density of water is 1 g/ml, so 5 ml of water is the same as 5 g of water.

The amount of herb material that is used to prepare one bottle
(990 ml) of tincture with the removed stalks below.

When I am harvesting any herb, it is important for me to determine in advance how much that I am going to need. That means the number and size of the bottles of tincture that I need to prepare, how much of the usable portion of the herb I need per bottle, and approximately how much extra that I need to harvest to account for the unused portion of the plant. I don't want to be short or I might have to go out again to harvest the same herb. In some cases, due to the number of herbs that I need to harvest, weather conditions, etc., harvesting an herb a second time might not be possible. So I might run short before I am able to prepare it again the following year. The flip side is that I don't want to over-harvest because it is wasteful and disrespectful to the medicine. When I'm out harvesting I bring a small spring scale that is accurate to within 10 g, so I can make sure I harvest the right amount. I will always harvest just a bit more than I need so that I don't accidentally run short. Any small amounts of extra herb I dry and use for teas.

After I processed 165 g of the usable portion of the blue vervain to make my bottle of tincture, the amount of stalk that I had removed was 51 g. That means that I had to harvest an extra 31% of the herb to get the amount that I needed. If I had harvested the blue vervain a bit later, the proportion of unused stalk would have increased because as the plants mature the stalk gets stiffer and the amount of stalk between the nodes (the points where the leaves join the stem) gets longer.

Once we have measured the appropriate amount of the usable parts of an herb, we need to chop it up. For this we need a fairly large hardwood cutting board and some kind of knife. Over the years I have experimented with just about every kind of knife for chopping the many herbs that I use. Some herbs are best chopped using a cleaver, a few require a serrated knife, but for most herbs the best knife by far is the mezzaluna. This is a curved knife with a handle at each end (see the first photograph in this post). When used correctly, it can finely chop herbs much more quickly than other knives. This is important because the process of chopping our herbs requires finding a balance between two opposing requirements. On the one hand, the more finely we chop the herb, the greater the surface area that we create that allows its constituents to dissolve in our menstruum. On the other hand, the more finely chopped our herb and the longer it takes to do it, the more it is exposed to air which results in greater oxidation of its chemical constituents. Most constituents are less potent when oxidized and in some cases it may even change their properties. It is true that a few constituents are more potent when oxidized, but this is not the case for the vast majority of them. In addition, they will have plenty of opportunity to oxidize after we press the herb, the final stage in making a tincture. For the best results, we want to minimize the amount of oxidation that takes place before and while the herbs are macerating. Maceration is the process of soaking the herbs in our menstruum. With the mezzaluna, I can chop an herb a little bit finer than I would with other kinds of knives in about half the time. It doesn't get any better than that! I really love those special tools that significantly increase the efficiency of the work that I do. The mezzaluna is one of those special tools. In choosing a mezzaluna, it is important that it be a larger one, 25-30 cm (10-12 inches) wide. Do not skimp on quality. Purchase one that is professional quality. The best ones are made in Italy or Portugal using high quality molybdenum vanadium steel. The ones made in China are not good. Also, only use the ones that have a single blade. One of my students once bought one with a double blade. She though this would make it easier. All it did was slow things down because the herbs kept getting caught between the blades. I don't believe they even make double bladed models in Europe.

Using a mezzaluna takes a bit of practice. Basically we hold the handles and rotate the blade back and forth over the herbs. Each time we do that we twist the blade to change the angle very slightly, first one way and then the opposite way on the next stroke. This allows it to move forward across the cutting board. What works best is to cut moving forward down the board, then begin at one of the front corners and cut diagonally in one direction, then cut diagonally in the other direction from the other front corner. Keep rotating between cutting in these three directions until the herb is chopped the right amount. It is very important that the cutting board is oriented so that the grain of the wood is running down the board away from us. Never use a mezzaluna to cut parallel to the grain of the board. This is because when we slightly twist the blade at the end of each stroke, if we are cutting with the blade parallel to the grain, it digs between the layers of wood. Over time it will start cutting out thin slivers of wood which will significantly reduce the life of the cutting board.

This is the what the herb should look like when it is sufficiently chopped.

This is the end of Part 2 of this series. In Part 3 I'll discuss making a blue vervain maceration.

Making Medicine, Part 1 of 5: Wild Harvesting Blue Vervain

This is the first of a series of five posts in which I am going to use the process of wild harvesting and making a fresh herb tincture of blue vervain (Verbena hastata) as an example to explain in detail the process of making medicine. You'll have to excuse me for having changed the title a few times. As I've been writing these posts, they've become longer and more detailed and less about blue vervain and more about making medicine in general. There are a lot of aspects of this process that I realized needed to be explained in detail. So this has been an evolving process.

A week ago, Monika (Monika Ghent, my partner and the Living Earth online course supervisor) and I went harvesting blue vervain. I decided that this would be a good herb to feature in in this series because the process is pretty typical for an herb for which we harvest the aerial parts. Also, being a wetland species, it allows me to address a couple of issues that are particular to harvesting in wetlands.

The home of blue vervain (Verbena hastata).

Back in the early 80s when I first started exploring wild spaces and eventually herbs in the rural areas beyond the boarders of Toronto where I lived, I used to look at detailed maps of the surrounding area to look for wild spaces where there weren't any roads and hopefully no development (that was before the Internet and Google Maps). When I found something that looked promising, my friends and I would drive around the area to get a sense of the landscape and determine if there were any trails accessing the area. In the winter I used to hike along the course of a creek near where I lived by walking on the ice. One winter day when we were exploring a new area I suggested that it would be easier and more interesting to access the area by walking on the ice along a river that flowed through. We didn't get as far following the meandering course of the river, but we didn't care. I have always preferred quality over quantity. After that day doing this became a regular activity for me. Sadly, for the last decade or more the winters in my area have been much warmer and the rivers rarely freeze. Occasionally when they do the ice is usually too thin to walk on.

The summer following our first river ice excursion we were heading out to explore a provincial park not too far away. We wanted to avoid most of the people and explore areas that weren't easily accessible by trails. I suggested that we walk up the river. So we put on old running shoes without socks and walked up through the river. We called it "water walking" and I've done it ever since. In the early days the only drag about it was the water sloshing around for awhile in our running shoes when we left the river. For a couple of years in the early 90s I took a bunch of workshops in New Jersey with Tom Brown. The first time I was down there a few people were wearing these really cool sandals that had adjustable Velcro straps. They were Tevas of course! They weren't very common yet and I had never seen them before. I realized at once that these were the perfect all-terrain footwear for use in warmer weather, and in particular for water walking. They were the one piece that was missing from water walking. I bought my first pair 20 years ago. I'm still on my second pair. That's pretty amazing considering they are about the only footwear I use (when I'm not barefoot) during the warmer months of the year. I wear them through just about everything when I'm harvesting, hiking, canoeing or camping.

So now let's get back to wild harvesting. Wetland plants often live in areas that are not easily accessible. The plant growth can be very thick and difficult to get through. There can also be deep muck that is hard to walk in. There is also a particular kind of grass that grows in wetlands that we call "sticky grass". I don't know what species it is. Grasses can be difficult to identify and I haven't devoted any energy to learning the many grasses because I don't use any of them. What is particular about sticky grass is that it has a row of tiny barbs along the mid vein of the blade that slices your flesh. If you walk through it with exposed skin you will get numerous cuts that are like paper cuts. It's not very pleasant. With these challenges in mind, in the early years when I first started wild harvesting the medicines I realized that the best way to access wetland plants is by water walking along the course of a creek or river, or along the shore of a lake. Of course it only works when the water isn't too deep. Another concern is that we have to be very careful not to step on any flat rocks because there are often fish, crayfish or other aquatic animals living underneath them.

Monika water walking while we were harvesting blue vervain.

So on July 1st Monika and I headed off water walking down a river that is not too far from where I live. Monika needed to harvest blue vervain and yarrow (Achillea millefolium), both of which are common along the banks of the river. That day I only needed blue vervain.

Whenever I pass through wild spaces I am always keeping track of lots of information: How healthy is the ecosystem? Which plants are growing there? At what stage are they in their life cycle on that particular date of that particular year? Do any of the medicines I use grow there and, if so, what is the maximum sustainable amount that can be harvested? What mammal, bird and other animal species live there? When I get home I record all of this information in a data base and update it every time I'm in the area. In this way whenever I need to harvest a particular herb, I have a quick reference to locations where it grows and approximately how much I can harvest at each location.

While I'm moving through the landscape I keep my mind quiet and tend to use my peripheral vision most of the time so that I can be aware of as much of what is going on around me as possible. Fairly soon after we started down the river last week I noticed a flash of red way off to my right in a clearing between some cedars. To my surprise I noticed some Oswego tea (Monarda didyma) that was just starting to bloom. It was early for these parts, but most species are blooming two to three weeks early this year because of the heat and the drought we have been experiencing. Oswego tea isn't very common in southern Ontario. It is much more common south of the Great Lakes. It only grows in a couple of the areas that I frequent and this was only the second time that I had seen it in bloom. Luckily I had my camera with me that day. In our area wild bergamot (Monarda fistulosa) is fairly common and that is the species that I use. When I first started using wild bergamot there was almost no information on it in the literature. There was a bit of information on Oswego tea and the few references to wild bergamot usually just said that it was very similar to Oswego tea. It is not uncommon for plants in the same genus to have very similar properties. Because several sources had made this comparison, I had assumed that they probably taste very similar. Then one day a few years ago Monika and I were walking along a deer trail on the bank of the same river further upstream from where we were last weekend. As we were walking I picked up a strong scent of wild mint (Mentha arvensis). I looked around where we had been walking and all I saw were some baby wild bergamot plants. I tasted a leaf and sure enough that was where the smell was coming from. I then realized that they weren't wild bergamot (although at that stage they looked almost identical) but rather Oswego tea. So it turns out that although Oswego tea is very closely related to wild bergamot, it tastes almost identical to wild mint. That means that the components of its essential oil are more similar to wild mint and therefore its medicinal properties are also probably closer to wild mint than wild bergamot. It seems that the information I had read was based on an assumption, not on experience.

Oswego tea (Monarda didyma), one of the friends I met that day.

Blue vervain grows along the edges of wetlands, rivers and lakes. In my area it rarely grows in large groups. It tends to grow singly or in groups of a few plants along the edge of the water or a bit further back in areas where it is wet in the spring and the soil remains fairly moist through the summer. As a result, it is necessary to travel some distance along the edge of the water to get a decent amount, especially since we don't harvest all of the plants.

A group of blue vervain plants growing along the bank of the river.

Blue vervain can tolerate a wide range of light conditions. It prefers to grow in locations where it will get direct sunlight 20-100% of the day, although 40-80% is ideal. In very hot dry years when the water level where the plant is growing is very low, it is best to harvest it in areas where it gets direct sunlight 20-40% of the day. On the other hand, in cool wet years it is best to harvest this herb in areas where it gets direct sunlight 80-100% of the day.

On this trip we were able to harvest a larger percentage of the plants that were ready because it hadn't been flowering for very long and only about a third of the plants were blooming. This year I only needed to harvest enough to make 2 litres of tincture because I made extra last year. I had already prepared 1 litre a couple of days earlier from a different location. Monika needed to make 2 litres as well. We had to water walk about 2 km along the river to get enough for both of us. In years when I need a fair bit I usually have to harvest at two or three locations to get what I need.

A closer look at the flowering spikes.

Blue vervain is harvested at the beginning of it's flowering period. The best time is from a few days to a week after it goes into flower. However, since all of the plants don't go into flower at the same time, generally the best time is one to two weeks after the first plants go into flower. In the area where I live, that is usually the second week of July. It was earlier this year because of the very hot, dry weather. It can be harvested a bit later, but like most plants the internodes (the sections of stalk between the nodes, the points where the leaves are attached to the stalk) get longer. This results in a higher stalk to leaf and flowering spike ratio and therefore a greater amount of stalk that needs to be discarded when we separate the usable from unusable portions of the herb. Also, the later we harvest it, the less time the plant has to produce more flowering stalks and reproduce. Typically we harvest the terminal 30-40% of the herb because this is the most potent part and it minimizes the amount of stress on each plant to regrow.

Me demonstrating how much of the plant to harvest. I am standing in shallow water in the river

and the plant is on the bank, so it looks about 6-8 inches taller than it actually is.

We had a great time water walking that day. It was quite warm, but a few degrees cooler than it had been. The sun was very strong, but travelling through the river there was a fair bit of shade. Water walking is great on hot days because walking through the water helps to cool us down. We also enjoyed the songs of many bird species and met a few friends along the way, both in and out of the water.

Some of the other visitors to the river on that day were

Canadian tiger swallowtail butterflies (Papilio canadensis) and...

...white-tailed deer (Odocoileus virginianus). We didn't see any deer but we heard them

bounding off as we approached. I usually only see them when I'm harvesting alone.

This is the end of Part 1 of this series. Later this week I'll post Part 2, in which I will be discussing preparing the blue vervain that I harvested in order to make a fresh herb tincture. In the third post I will discuss making the maceration; in the fourth, different kinds of equipment that are available for pressing and filtering tinctures; and in the fifth, the actual process of pressing and filtering the maceration to make the tincture. In the last post I will also provide information on the properties and uses of blue vervain.