Using a Pot Still
Update: While this page is very useful for beginners, some of the information is not accurate. Running too far into the tails will not create a spirit which will kill you. You may get a hangover bad enough you'll wish you were dead, but it won't kill you. Also, the risk of methanol is greatly overstated. Focus on the information being shared regarding the process, it will be very useful as you begin to hone your skills. - Uncle Jesse, August 22, 2022.
A pot still is fairly straight forward to use. Turn it on. Once the temperature is up to about 60°C; turn on the cooling water to the condenser. Make sure you throw away the first 100mL per 20L wash, as this will contain any methanol that might be present. Segregate the distillate into 500mL lots as it comes off. Only keep (for drinking) that which doesn't contain fusels (smell off) - probably below about 92°C, however you should keep distilling past here, until about 96°C, as this fraction, although high in tails and not good for drinking this time, can be added back to the next wash and cleaned up OK then.
Graham describes using his ...
I single distill as I have no need to purify my spirits. The concentration at the top of the tower can be controlled with how much heat i apply at the bottom. If I want a pure spirit, I apply a low heat and can run it off at over 90%. with a bit of a twig I have hit the magical 97.5%. But you get utterly no flavours. I apply more heat, so I get a run at about 70 to 80% and get the flavours I need. Its true people, about about 80% you start to lose flavours.
I normally cut my runs when the alcohol drops to about 40%. The heat put in compared to what I get isn't worth it.
>How do you judge the "cut points" for foreshots and feints?
Ah the terms they use for this "firsts and lasts", "Heads, Hearts and tails". for those who dont know, The flavour of any spirit come from a wealth of compounds, alderhydes, amy alcohols (fusal oils), esters, acids and even methanol. The desirable ones are commonly called congeners. The art of any distiller is knowing when to start collecting the heart and stop it again. Start it too late and stop it too early, and you collect mostly pure ethanol and no flavours. Start too early and stop too late, well you make something that will have a lot of flavour, but will give you ripper hangovers, could even kill you.
The art is to collect enough of the congeners in the last of the head and beginning of the tails to get the flavours, but not enough to make it undrinkable. You do this by watching the thermometer at the top of the still. When the firsts start, it will sit at 65C-70C. This is mostly methanol coming off. This you dont want. Then it will suddenly rise as all the methanol is removed. It will rise to 78-low 80s (depending on heat and what you want).
This is the heart. Now for a good rum, you want lots of flavour (and the headache with it) so you start collecting as soon as it starts to rise. For a whiskey, I tend to collect when the temperature hits 78C. For clean spirits, I wait till the temperature stabilises. The same occurs at the tails. The temperature suddenly heads for the 90's, and thats agian when you decide to cut it as the higher alcohol start to evaporate and collect. This I do by the the highly accurate method of tasting it.
The Omnipresent Mecakyrios advises how he uses a Doubler with a pot still ...
Here is what I have done in the past when using a doubler:
I would fill the boiler to the normal capacity with my wash. I would fill the doubler 1/3 full with wash as well (sometimes I would put in 50/50 wash and neutral spirit in the doubler). I would run my batch. If I still had another run to do that day I would throw our the spent wash in the boiler, fill the boiler with the new wash to be ran, add the liquid that was in the doubler into the boiler with the new wash, fill the doubler with new wash adding to it the tails of the run that I had just finished, and start the run. I keep doing this until I have no more wash to be ran.
At the end of a day's run, I toss out the boiler and doubler liquids. I keep the tails until my next run. Sometimes, if I have patience enough, I will store the distillates of that days run and add them to a previous run's distillate. In other words, let's say that a month ago I did a run and had collected one unit of distillate from the first run of the day, a second unit from the second run of the day and a third unit from the last run of the day. I will combine all of the units together and mix them up real good. I will then take one unit worth of distillate and set it aside. I will take the remaining distillate and put it into a container and label it with the date. The unit that I had put aside is for me to drink while I wait for a whole month to go by. Then let's say I did a run today and had collected three units of distillate. I will combine these, put one unit worth aside and add the rest to last months run. I will continue to do this until I have a month of down time.
During the down time I clean out the still real good and take the bottle of several months worth of distillate and draw of one unit worth for me to drink, the rest of the several month collection is bottled, sealed, labeled and stored away and forget about it until a special occasion happens when a good aged product is called for.
Jack writes ...
I use an enlarged ice water/wok type of still, so a thermometer cannot be used- I just go by volume. With a mash starting at about 5 to 10%abv, do the first run, and collect 1/3 of the total mash volume (I.e. Put 3 gallons of mash in the still, keep collecting until you get one gallon out of it). On the second run, I collect one fourth of the total I put in. I.e. distill 2 gallons (8 liters) of low wines, keep collecting until I get 1/2 gallon (2 liters). I also collect heads on the second run at a rate of 150ml to 200ml per each five gallons of (starting) mash volume. Making sure a thermometer is reading the same every time I do a run was too much of a hassle.
Scrounge adds ...
I don't bother with temperature - I used to but after a couple of runs I discovered that relying on the thermometer lead to rather unpleasant off notes.
My still is 6l, I usualy put in a 3l wash ( or 1.5l if it's a lumpy fruit wash ), I discard the first 10ml and then put a jug under the outlet, every 50ml I swap jugs and transfer the spirit to a bottle. I sit there with a shot glass, a spit bucket and a glass of water and every so often I collect a few drops from the outlet and taste. It's up to my tongue where I stop collecting.
Big tip - before mixing fractions try mixing a small quantity separately - some fo the later fractions have a bad habit of suddenly clouding when added to the earlier.
My final ABV - using a set of volumetrics in the lab is 60% on the first run, for Eau de vie I don't often do a second run but sometimes I will add all fractions from previous runs to last was and collect that with a lot of care.
If it's relevant my lyne arm is 1m long and has a slight upward incline.
Jack uses a combination of freezing and his potstill, to maximise the flavour ...
I found by trial and error the flavor on "double run" whiskey wasn't as good as single run whiskey (although I got less whiskey doing it that way- tighter middle cut). Instead of running my still twice, I now use the technique that was/is used to make apple jack.
I take my 5 gallon batch of mash/wine, and I fill 10, one gallon milk jugs half-full (one half gallon being 2 quarts) of the liquid. I then put these jugs into the freezer for two or three days, until they freeze into a solid block of ice. I then set the jugs upside down on a one quart canning jar. The alcohol will drip out as the ice melts (don't add any heat- let it go at it's own pace). When the one quart jar is full, I put the liquid (in the jar) into my carboy to let the yeast, etc settle out overnight. The block of ice in the jug is washed down the drain with hot water- there is no alcohol in it. Since the alcohol melts faster than the water, it tends to come out first- so instead of 5 gallons of 7-10% mash/wine, I now have 2.5 gallons of 17-20% mash/wine.
It takes no real effort on my part, but gives the same results as a beer stripping run, roughly doubling the alcohol content by cutting the volume in half. It doesn't stale the flavor like distilling can do at all, quite the contrary, it makes it stronger- this same method is used by some winemakers to make fortified wines at home (like port, sherry, etc.), without using distilled spirits. By cutting the volume in half, and doing it by freezing, not distilling, the flavor is preserved a little better, but the alcohol is high enough that a spirit run can be done. It typically takes one to four hours for the quart jars to fill up- it depends on the starting alcohol content- the lower it was at the start the longer it takes to melt out. It saves a lot of time for me, since I have a lot of freezer space.
When I make my malt whiskey, it used to always foam over in the still- by freezing it like this, then diluting the mash back to 5 gallons with water when I put it in the still- the starches causing my foaming problem have been diluted to the point that they can't lace together and foam up in the still. In the potstill, it just saves me 4 hours of work on an extra run. While the stuff is melting, I check my e-mail, work out, read, or whatever I feel like doing that I can't do when running a still, because that requires all my attention.
Bill writes ...
I have clear tubing from pot to worm and can see the vapors forming, so I know when to start cutting back on the heat, as soon as it starts to run I toss the first 100ml or so then just fine tune the heat so that I get a slow steady stream, run it down to 40% collect the bottoms for the second run, dump the lees and start another run.
I usually run it through at least twice and usually three times to get it as refined as possible. No hint of fusel oils at all, as proved by drinking it in massive quantities all one night with absolutely no hang over the next day. I use a propane camp stove to heat the pot as i find it has greater control capabilities.
I have been trying the hyper yeast from Gert Strand, am not impressed with the results, a little too yeasty in the aftertaste, could be something i've done wrong, but tried three batches with basically the same result. I will probably go back to using my old receipe for base whiskey, 2 cans of frozen orange juice, 2pkts champagne yeast, 4kilos white sugar and water to 25 litres; you can then feed the resulting mash as the gravity drops till saturation.
Tried a rum with fancy molasses 1 gallon 2 yeast water to specific gravity that appeals to you and your yeast, had a friend that works for a distillery, he went on a junket to pourto rico, where they have a distillery, he brought back a bottle of their finest, we did a blind taste test and couldnt tell the difference. Of course after several more taste tests, we couldnt have told the difference from dish water, needless to say I didnt let him drive home as he would have blown the ass off a breathalizer.
John gives his views ...
A potstill is a direct descendant from the medieval alembic still favored by alchemists, and often shown in old woodcuts. The alembic still was a cooker or boiler with a small conical lid with a sideways protruding tube. Its curving form causes it to be named "swan's neck". The latter led into the cooling coil which sat in a waterfilled vat. The modern potstill has a column (variable length) inserted between the cooker and the swan's neck.
In terms of the modern reflux column which, even in our amateur hands, can consistently deliver 95-96% pure spirit, the pot still is very inefficient. It delivers only impure mixtures of ethanol, water, and congeners. For that reason one usually double-distills (redistill) the wash - the first time delivering a distillate at ca. 30-40% abv, and when re-distilled raises this to 70-80%abv. Even then the product still contains congeners in addition to the ethanol. However, it are the congeners that impart the flavour of the grain or fruit. And most of these come from the 'tails'. As Ian Smiley puts it, the tails 'bleed' into the middle cut. While the reflux still can produce mind-stomping purity, the pot still must be run with a sense of art.
Why double distill? The abv would be right on from the first run (35-40%). Is the first run still too harsh to drink?
One double distils to increase the alcohol content, but more so to concentrate the congeners. Note that in pot stilling the focus is on the 'also-rans', the congeners, and not on the alcohol!! The pot still is all about flavour. The first distillate from say a malt / barley run is insipid, but better than the wash was. However, when that distillate is run through again, and more water is discarded, the congeners are further concentrated. The final taste of a single malt whisky is likely about 70% congeners from the wash, and 30% from the cask wood.
The art lies in knowing how much of the congeners to allow into the middle cut.
Cut-off point? That depends on one's sense of taste, and on what sort of whisky or brandy one wants - highly flavourful, just right, or overwhelming. Ian Smiley devotes several fine pages on this point - viz. pp. 72-74. (Making Pure Corn Whiskey. 1999. ISBN 0-9686292-0-2; http://www.home-distilling.com/) . It is a matter of deciding how much of the tails one collects into that middle run.
What are your feelings on the notion of increasing the sugar content in a berry based wash by adding sugar ?
I suppose that depends on which is desired - fruit flavour or ethanol strength. One could argue that blended scotch whisky is in fact sugar based, as a blended whisky is a mix of single malt whisky and grain alcohol, where the latter is highly purified grain distillate, devoid of grain taste. Just the opposite, in eastern Europe slivovitz (plum eau de vie) is double distilled from soft ripened plums, often weeks old, left to ferment in tubs with natural yeasts. Now, that distillate should be plenty flavourfull but in some regions more ripened plums are added to the distillate to further enhance the plum flavour.For me, it is all about flavour, so I go for the fruit or grain.
Michael writes about distilling a wash made from beer kits, to make whisky ..
Coopers Lager comes out very much like a scotch whisky.... There are also malt extracts available at any home brew shop that can be added. Both liquid and crystalline form. These are for use in beer brews, but will make the transition to distilling just as well. Putting two beer kits into the brew keg makes for a stronger flavour too.
I do a stripping run first. Reflux down as low as possible. I have a still spirits still which I have modified into a compound still. I have the original head and a second lid so that I can use this as a basic pot still. The short column originally had a cooling jacket and a marble. I have disconnected the jacket and removed the marble.
Final cut point is a matter of taste and flavour. I am generous with it at this stage since I am going to do a second distillation and can be more picky there.
I don't separate out any heads from the stripping run. The reason for this is that I then stick it into my compound head, water it down and bring the still to full reflux. I let this stay for an hour, and then take off my heads as normal. Once I have got the heads out of it, I turn the still off and let it cool. Then I run it through the pot still again, taking more care that the final cut point tastes good. Water back to 50% and oak. Voila!