Single run distillation take off rate

[1Dmax]

Hey yall,

I just introduced myself over in the welcome forum. I am running a 15 gallon keg potstill with a 6 inch long 2 inch wide column. It reduces to a half inch pipe and goes up another 6 inches or so before taking a 90 degree bend and then an angled 45 for the liebig which is 3 to 4 feet long 3/4 over 1/2. Already did cleaning and sac run. The wash I am running is second/third gen UJSSM around 12.5% abv with Still Spirits Whiskey yeast (pretty sure it ain't a turbo). The wash tastes as I would expect so I don't think any problems there but I may try shooting for 9% in the future to avoid any yeast stress. I am interested in 1.5 times distilled or single distilled as I have tried stripping and then spirit (on my 5 gallon still) and found quite a bit of flavor loss. I stripped a boiler charge and added it to a fresh charge of wash and did a long spirit run on it for about 4-5 hours(fast drips/broken stream with slower drips for the fores) collected in 500 ml jars.

I aired her out for a couple of days before diluting and tasting the hearts and its nothing to write home about. Now my tastebuds are about as green as grass, but it seemed pretty damn smeary and hot, even for white dog. I got to thinking maybe I need to go a mite slower than your usual spirit run because it is a single(ish) run. It could be the mash but it tasted pretty solid, it was sourish, corny, and a mite bitter but no off flavors. I thought you folks with some expertise on the matter could save me a bit of pain and suffering by helping me dial in on a better take off rate preferably in a quantifiable manner i.e. Liters per hour.

I know that every still is different and needs experimentation but I could use a better starting point. It seems only a select few members seem to run a single or 1.5 so I would love to hear from them. I have read alot of the forums material and would just like a bit of specific advice. If you see anything that looks wonky with my procedure or you need any other information please tell or ask. Also feel free to holler at me if this post is in the wrong spot.

Thank you for sharing your wisdom
Happy Stillin

[jon1163]

I stripped and spirited mostly but my last two runs have been one through a pot and thumper. I also run a 15 gallon keg boiler and an 8 gallon keg thumper. I am liking the taste of my 1.5. I take the first pint really slow (like 2 drops a second) then I up the rate to a broken stream.

[still_stirrin]

1Dmax,

Doing a 1-1/2 distillation run (adding the low wines from your 1st strip to a 2nd run) will increase the flavors and your off still proof.

But I suspect that the issue with your “hot liquor” is proper cuts. I’ll be you “dime to a dollar” that you’ve included a lot of the tails (or smeared product) into your hearts cut. More than likely the reason for the objectionable quality is too wide of a “center cut”. Inexperience with cuts is often the case, although equipment and how it is run can make clean cuts difficult.

With your still...a 1/2 barrel keg and propane fired...the 2” riser is a proper size outlet. But, reducing to 1/2” so close to the boiler outlet forces a lot of vapor into a small pipe while it is still hot. This causes excessive vapor speed which will lead to a lot of smearing. If you were to raise the riser as 2” up to 12” above the boiler outlet and then turn 90* with a 2” elbow before reducing to 1” pipe (or 1-1/2” pipe) through a short section before reducing to your Liebig’s 1/2” inlet, the vapor speed would be more manageable.

Running “low & slow” would help, but being propane fired it may be difficult to adjust the heat input with finesse. By nature, a potstill will smear but excessive vapor velocity will significantly increase it.

In summary, you’re probably getting a lot of the heavier alcohols (fusels) pushed throughout the run (smeared). Redesigning your stillhead would help. And adjusting the operations will help too. Finally, experience with cuts will give you a better understanding of the “hearts” from the “feints”. You can get a lot of good flavor off of a potstill with single runs or 1-1/2 runs. Even 2X runs will get you a good tasting liquor. But don’t get greedy...be selective.

Be safe, responsible, and discrete.
ss

[1Dmax]

I don't think the issue is with cuts as I tasted and diluted every 500 ml jar individually and I didn't taste any super clean hearts. Yes I was worried about the excessive vapor speed with the design but for the time being that was the best design I could manage. In addition to running really slow is there any way to decrease the vapor speed? Perhaps a damp towel wrapped around the 2" riser?

Thanks!

[1Dmax]

Sorry for the double post!
I am planning on packing the 6 inch riser with copper mesh and placing a damp towel over the riser to induce a little bit of reflux that may counter act some of the smearing from the high vapor speed in addition to running very slow. I do have a question of the impact of high vapor speed on smearing. As far as I have read the only vapor speed that matters is the speed of the boiler charge turning into vapor, i.e. the speed or vigor of the boil resulting in the vaporization of alcohols with different boiling points boiling off at the same time. The reduction from 2 inch to 1/2 inch shouldn't effect the vigor or speed of the boil only the speed of the already separated fractions of vapor in the column itself. I would appreciate any illumination of the subject.

[still_stirrin]

The reduction from 2 inch to 1/2 inch shouldn't effect the vigor or speed of the boil only the speed of the already separated fractions of vapor in the column itself. I would appreciate any illumination of the subject.

The “vigor of the boil” creates vapor (in terms of mass per second). If the vapor speed (flow velocity in terms of distance per second) is slow, then it may release some of its heat to the surroundings and begin to condense.

If the vapor velocity is fast, it can’t release much of its heat to the surroundings. Changing from 2” ID to 1/2” ID is a 16:1 reduction in crossectional area. If mass flow is constant, then the vapor must accelerate. This is why you don’t want an abrupt change from such a large diameter to such a small diameter. The vapor in the 1/2” pipe is so fast that it wants to steam right through the pipe without giving up its heat.

Now, if the vapor flow is too fast, it can “choke”, that is - reach a point where it can’t flow any faster without the source pressure increasing. If you put enough heat into the boiler such that the flow chokes in the piping, then the boiler pressure will rise. This is the physics of compressible (vapor) flow.

And as the pressure in the boiler increases, so will the boil point of the mixture (wash). And this can affect the smearing and taste of the product off still, especially for a “one & done” protocol.

Are you beginning to “see the light”?
ss

[1Dmax]

Interesting, so if there is enough back-pressure to increase the pressure in the boiler, smearing would occur due to modified boiling point. That is sound chemistry in my book. So the issue with the abrupt change in diameter is both the back-pressure and the issue with the lack of condensation(passive reflux?). I could never have imagined that the the change in diameter would result in any sort of significant back-pressure during a slow spirit run. I understand that but am still rather curious about the condensation you are referring to. This condensation seems to be implying passive reflux which I thought was non-existent on a pot-still. Are you implying that passive reflux is actually a semi-significant factor in potstilling???? Thank you very much for your input in the subject. I have noticed a significant put-put sound coming out of the liebig and the top of it was warm. I will attempt the packing and towel method with a super slow run on a boiler charge filled with low wines and see if I can get passable results until I can redesign the still head. Some light is definitely getting through to me!!!!

FYI the flavor is absolutely bonkers good but the burn is just too much!!

[googe]

12.5% is pretty high, especially using a pot youll get noticable off flavors. you sound like your over thinking things. A pot is the simplest toll there is. Do multiple runs if you want to split fractions better or make a reflux still.

[1Dmax]

I will try a lower wash abv but the wash tastes great with absolutely no off flavors which lead me to believe it had to do with the distillation process.

[Pikey]

Hey yall,

I just introduced myself over in the welcome forum. I am running a 15 gallon keg potstill with a 6 inch long 2 inch wide column. It reduces to a half inch pipe and goes up another 6 inches or so before taking a 90 degree bend and then an angled 45 for the liebig which is 3 to 4 feet long 3/4 over 1/2. Already did cleaning and sac run. The wash I am running is second/third gen UJSSM around 12.5% abv with Still Spirits Whiskey yeast (pretty sure it ain't a turbo). The wash tastes as I would expect so I don't think any problems there but I may try shooting for 9% in the future to avoid any yeast stress. I am interested in 1.5 times distilled or single distilled as I have tried stripping and then spirit (on my 5 gallon still) and found quite a bit of flavor loss. I stripped a boiler charge and added it to a fresh charge of wash and did a long spirit run on it for about 4-5 hours(fast drips/broken stream with slower drips for the fores) collected in 500 ml jars.
..................

I know that every still is different and needs experimentation but I could use a better starting point. It seems only a select few members seem to run a single or 1.5 so I would love to hear from them. I have read alot of the forums material and would just like a bit of specific advice. If you see anything that looks wonky with my procedure or you need any other information please tell or ask. Also feel free to holler at me if this post is in the wrong spot.

Thank you for sharing your wisdom
Happy Stillin

I run singles with the feints added back into the boiler charge, on what is similar to a pot.

Firstly I agree about the flavour loss and my recipes are adjusted to produce a little less flavour in the wash, but I run around 12% all the tiime, with no "Off-flavours" at al, except when I used Turbo once or twice at the beginning.

However, My column is 40" to the offtake. It is 1" copper all the way, with a 1" tee and the arm is agin T'd onto a 1" vertical which contains a Dimroth condenser and I take a steady pencil lead stream.

I have never understood teh point in having a wide riser, then restricting it down to a half inch before the condenser. It just seems like a waste of copper in teh wider part, since the flow can only go through the half inch part at a certain rate. WHat difference does the 2" portion make ?

My first runs were done before I found any info on line and although I took off the "Fores", I did nothing about "Cuts" and again my first runs were of a "Sour mash" a bit like UJ.

It was ok when mixed. LAter I found out about cuts and it got somewhat better. - HOWEVER there was a slightly "musty" taste which I did not care for too much and my "mentor(ish)" confirmed this was normal with a corn wash. I have never had any problems with my "Bacardi(ish)" or my "Easy Scotch" - Just with Sour MAsh. - So if that's what you mean by "off-taste" that may be your answer. It may also be that Double distil removes that "mustiness" I don't know. (Oh Both those receipes are in the forum somewhere - use the Google search if you'd like to try them. ) - PS if you drop down to 9% wash, it's most unlikely you will get a decent strength product without Double distil - which of course takes you back to square 1 )

Sorry I can't help directly as my pipes differ greatly from yours, but I hope I gave you dsomething to try out.

[Antler24]

My still is setup the same as yours, piping and all. I just do 1 run through pot and thumper lately. I just thought I'd say unless your used to drinking traditional moonshine or corn whiskey, you may need to age your stuff a bit. I don't care for any of it "white". Everything I make goes on oak.