Hi, this is Thomas Easley, planning director of the Eclectic School of Herbal Medicine,
and the co-author of the Modern Herbal Dispensatory, and today I'm with Mountain Rose Herbs,
and we're going to demo how to do an herbal percolation. Percolation is
one method to make herbal tinctures. The other most common method is
maceration, where you stick things in a jar, and cover them in alcohol,
and let them soak. They normally take three to six weeks of a soaking with daily
shaking to get all the constituents that are in the plant
into your solvent, into your alcohol water mixture. Percolations are convenient
because they're normally done in like 24 to 48 hours. They take a little bit more
work, but they're not quite as complicated as a lot of people think,
so let's dive right into it. For a percolation, you're gonna need a
percolation cone, and you can pay a scientific glassblower a lot of money
to make one for you, or you can use a wine bottle that you've cut the base off of.
A lot of people do the string and fire method to get the bottom off, and there are
glass cutters. What I found is that a wet tile saw works really well to make
a smooth cut that there's no chance of, you know, getting an edge that's going to
cut you. The wet tile saw you could buy new, but probably you have a neighbor
that's remodeled their house and installed tile flooring. Borrow one from a
neighbor, cut the bottom off ... I like the one and a half liter wine bottles
because you can get your hand in there, so they're easier to clean. Once you've
cut the base off, the other side is going to be a way to control your flow
rate. And, a lot of people use, instead of wine bottles, they use water bottles
with an adjustable lid and they control the flow rate too by tweaking
that lid a little bit tighter a little bit looser. One of my friends, Darrell
Patton from Alabama, figured out that you could use a needle valve that you can
purchase at most hardware stores, and I played around with a lot of different
stoppers and found a food-grade silicone stopper that works well. So we're going
to use this to control our flow rate. Then you need a container to catch your
tincture in, and if you need some way to hold that, you can just take your
percolation cone and set it right into a jar, but then you have to move it up
every time you need to adjust your flow rate with your valve. And so what I
recommend is getting a lab stand. You can pick one up for about 30 bucks, and
it's like getting an extra set of hands, which is really helpful when you're
preparing herbs. So what we're going to do today is make a percolation of
Echinacea angustifolia. All percolations are done with dried,
powdered herbs (you can't percolate fresh herbs). So, we're going to get our powder...
(See? Extra set of hands!) We're gonna take our herb powder and
we're gonna weigh it out because, unlike the folk method, when you are doing
percolations, you're going to go with a weight-to-volume ratio. So a standard
weight-to-volume ratio is 1 to 5. That means 1 gram of plant material that's
dried and powdered (and preferably sieved through like a number 60 screen),
1 gram of that per 5 milliliters of whatever solvent that you're using. In this case,
we're going to do a mixture of water and alcohol at a 50% alcohol volume. So in a
one and a half liter wine bottle, magnum wine bottle size, you can get about
a hundred grams herbs with enough space left for your menstruum.
So we're going to weigh out a hundred grams.
Good to go.
So, if we were to dump this dried herb powder into our percolation cone,
once our water-alcohol combination hit it, it would swell up and would not let fluid flow through, so we
have to pre-moisten our powder, and we do that with the same solvent
that we're using (in this case, 50% ethanol.) The technical way to do it
is to take your powder put it into a volumetric flask, compress it see how
much it displaces, and then you're going to pre-moistened about 65% of your
displaced volume. We're just going to eyeball it, because we're going for a
specific consistency of wet sand.
So, we take our menstruum, and add a little bit in,
and give it a stir.
And we're just trying to rehydrate our powder,
so that the cell walls expand to their maximum size and it doesn't swell once we add our menstruum in.
So this process of adding a little bit of your menstruum and then working it in
and making sure that it doesn't swell, or that it is fully-swelled but it's not
still drying, this takes experience.
I recommend the first few times you make percolations, use the cheapest powdered herb you can find,
so that if you mess it up, you know, you haven't just tried to percolate
five hundred bucks worth of American ginseng. Use of something maybe
that you have leftover or that's inexpensive, and play around with
this process. So we're getting to a pretty good consistency. What you'll find
when you're pre-moistening your plant material is that things will look really good,
and then you'll come back like twenty minutes later, and it's sucked in
more water, so you have to keep adding and tweaking for the first hour or so to
make sure that it's the right consistency. And once you get things
looking the right consistency, you want to put something over the top
to prevent your menstruum from evaporating, and then let it sit and just
soak in and hydrate for at least two hours (a lot of people say 12 to 24 hours)
but normally, you know, two or three hours and we're good. So this will need to sit
aside and make sure that it's absorbed all of the moisture.
I have already pre-moistened another batch, and this is the consistency
that we're looking for: it is wet sand, like, it clumps in your fingers, but falls
apart pretty easily once you drop it. So we have our Echinacea that has
been pre-moistened, it's at the right consistency, now we're going to
pack our cone. A lot of times when you pack and do percolations, or see classes
on percolations, they'll put a coffee filter in the bottom to hold the
plant material up. I did it that way for years, and then maybe a year ago
somebody said, "why don't you just use cotton balls instead?". So you can get
these unbleached organic cotton balls and just shove them in the neck of your
percolation column, and that will hold your plant material off of the bottom
and allow some space for fluid to fill. And we're going to put our valve in and
you want to be sure with these silicon valves (because they're pretty slick), that
you really press it in there. And then we're gonna open our valve up because, as
fluid moves through, it's going to displace the air, and if we keep our
valve closed, those air bubbles will come up and disrupt our packing of our
pre-moistened herb. So we're gonna open that up until everything runs through.
Then we're just going to tighten this down and start adding our plant material.
This is done in thirds. You're going to dump about a third of your plant material
straight into your percolation cone.
And once you get about a third of your plant material in there, you need to
slightly compress it. So we're going to tamp it down and what we're doing here
is just making sure that the consistency of the powder is even, because we want an
even movement of our menstruum through our plant material. If you over pack,
if you tamp down too hard, then your fluid won't be able to make its way through.
If you tamp down too loose, then your powder, once you add your menstruum,
will kind of float, which is not great. So it takes practice; I've been doing
this for years, and I still mess these up every now and then (I pack them too tight,
or I don't pack them tight enough), but once you get hang of it, it's
pretty easy to stay consistent. So we have that packed in now, we've got
a hundred grams, and we're gonna do a 1-to-5 extract, so we're gonna add 500
milliliters of our solvent. So if we just add it right now, it's going to
disrupt the packing, and all of the plant material will start to float around and
you won't get an even movement of your solvent through your plant material, so
we're going to take an unbleached coffee filter and put it in, and just kind of press it
in place so that when we add our solvent,
our powder won't float to the top.
Now what you're looking for, is an even movement of your menstruum through your plant material, so keep an
eye on your moisture level as it moves down and,
it should be moving at about the same speed all the way around. If it's not, then I
have kind of packed it equally. That looks good, you can see the menstruum
flowing through evenly through the plant material, and that's about two-thirds through now,
remember that our valve is open. Now at this point if your valve is closed, all
of the air that the fluid is pushing will bubble back up, and you'll get
little rivers through your powder, and you won't get an even movement of
your solvent. So keep the valve open until you start getting your solvent
dripping through your menstruum, dripping through the bottom, we're down to about
here. One of the benefits of percolation is that you're moving unsaturated
solvent here at the top through the plant material, and extracting the stuff
that's inside of plants works via a constituent or a concentration gradient,
so your menstruum will only pull out half of what is inside the cell walls of
the plant, but because our menstruum is unsaturated, as it moves through, it's
going to pull a little bit more than if we did a standard maceration.
Now there are no studies on this that I'm familiar with, but the general consensus
is that percolations (which can only be done with dried herbs, so there are some
drawbacks) but percolations are somewhere between like ten and thirty
percent more potent than standard macerations. I definitely have
plants that I prefer doing standard macerations on, but the majority of the
dried herbs that we turn into tinctures, I like this process of percolation.
So we moved all the way through the plant material
now our cotton balls (our filters) are slowly filling with our liquid. There's the first one,
so we're going to get ready, as it filters through, to close our
valve once all of that air has been displaced.
And of course if a few drops go through it's no big deal, but the idea is to ... there we go, our liquid's at the bottom, the air is
displaced, it starts to drip, and we just close our needle valve. Now, at this point
at this point, we pause and we let this menstruum sit with our plant material for about 12 hours,
and that process is called digestion.
And once our plant material has been digested by our menstruum, that means
that the solvent (the menstruum that is in contact with the plant material) has had
enough time to pull the constituents from inside the cell wall out into
solution. Once that 12 hours has passed, we're just going to start our
percolation dripping. So let's just pretend the 12 hours has passed. We're
just going to adjust our valve so that we get one drip every three to five seconds.
So a slow, steady drip of about one droplet every three to five seconds, and
this is, you know, set overnight and digested. This is going to take a couple
of hours to move the continual unsaturated solvent through the plant
material, and then, in a couple of hours, your tincture is ready. So percolation:
fairly easy to do, you do need to do a little bit of weighing and measuring to
make sure that you have a good weight-to- volume ratio (one-to-five is the most
commonly used one ...you can do one-to-one fluid extracts with a few extra steps),
and once you've weighed and measured everything, pack it in thirds,
remember to keep your valve open until it starts to drip, close it off, let it
sit 12 hours, and then open it back up so you get one drip every three to five
seconds. You'll have a finished tincture ready to go within about 24
hours of starting this whole process, and that's how you make percolation-based tinctures.