Distillation temperatures, step by step.

[Elut]

Bring up to boiling temperature (start the cooling water through the condensors once you get to about 50-60oC), then once it has started distilling;
Discard the first 50 mL's (this may contain some methanol),
Collect the next 2-3L of distillate.
Segregate the distillate into 500 mL containers as you collect it.
Stop distilling once the temperature gets to 96oC (else the flavours get nasty).
Set aside any distillate which smells of tails/fusels. This can be added to the wash of the next run, and cleaned up then.

Hi Everyone !

After reading the parent site several times, I still don't fully get the picture of the distillation temperatures.
If I correctly understand the parent site, it's just about letting the power source do its thing until the temperature
of the [alcoholic steam? Wort? Output?] reaches 96c.

I'm planning on building a temperature control based on the temperature readings of the wort and the steam.
So, upon your own experience, what would be the "best temperatures" to heat the wort at?

Would applying a constant 78~79c heat during the whole run be a good solution? If not, why?
Or at the contrary, should I get through several steps? If so, which?

Thanks a lot in advance, for explaining me more in details these blurry points !

[goinbroke2]

Temperature? We don't need no stinking temperature!

Couldn't resist..I don't go by temp's, got a pot still and I crank 'er until the lyne arm is too hot to touch and the chips are rattling, then ease up on it and collect foreshots.

[eternalfrost]

sounds like you need to go over the basics of how distillation works. gotta get the basic chemistry into your head before worrying about making anything drinkable.

Would applying a constant 78~79c heat during the whole run be a good solution?

you apply energy, not temperature. the chemical composition of the mash will dictate what temperature it is. a still is not an oven

try to boil a glass of water at "a constant 78C" and youll learn what you need to know

[Elut]

Eternalfrost,

First, thanks for being so rude and for giving me so few information
I guess that it's the warm greeting reserved to novice distillers from all-mighty
experienced distillers whom have never been beginners during their whole life.
Well, I "should get that in my head" before posting a question which is "o so basic".

As you told, a wort is not water, it's a lot of compounds all together. Why did you compare it to water?
Well, I might be wrong, since I didn't spend much time there, but a while ago, at school, I've learned
that ethanol is evaporating at 78~79c. And that H2O is evaporating at 100c.

So what would be the point of bringing it to a boil? Releasing things? Accelerating the process of evaporation?
Please develop a bit to enlighten my stupid person.

[Dnderhead]

The wash/mesh/beer (whats in the boiler ) does not make much difference it will be between the boiling temperature of
water and the amount of alcohol that is in it.

the head temperature is what you want if running a reflux still (a pot still wont work this way)
Acetone 56.5C (134F)
Methanol (wood alcohol) 64C (147F)
Ethyl acetate 77.1C (171F)
Ethanol 78C (172F)
2-Propanol (rubbing alcohol) 82C (180F)
1-Propanol 97C (207F)
Water 100C (212F)
Butanol 116C (241F)
Amyl alcohol 137.8C (280F)
Furfural 161C (322F)

as you can see you do not want anything 77c and below and nothing above 80c, this "middle" is "harts". above and below (except a small amount of fore shots)
can be put in next run to extrac more ethanol. these changes can take place very quickly and most controllers cant keep up.

[Elut]

Thanks a lot DND, I'm gonna use a pot-still (column), would it be adapted to check the temp under the cooling tube?

[Dnderhead]

as close to where your product is taking off as you can git .

[eternalfrost]

As you told, a wort is not water, it's a lot of compounds all together. Why did you compare it to water?
Well, I might be wrong, since I didn't spend much time there, but a while ago, at school, I've learned
that ethanol is evaporating at 78~79c. And that H2O is evaporating at 100c.

So what would be the point of bringing it to a boil? Releasing things? Accelerating the process of evaporation?

heh not meaning to be rude. just 95% of times when people speak of temperatures like you did they simply dont have a full grasp of how distillation theory works. not trying to be mean, just point you in the right direction.

i think giving even the relevant wikipedia pages a quick read through will be a great help


evaporation and boiling are two different things. basically there are inter-molecular forces holding the wort together as a liquid. temperature translates to average kinetic energy. at any temperature there will always be a handful of guys with enough energy to overcome these forces and break out as a gas. this is evaporation and happens at all temperatures.

this jump requires a chunk of energy called latent heat of vaporization.

boiling is not strictly necessary, see solar stills etc.

boiling is when the vapor pressure becomes equal to the ambient pressure. this means there is enough energy to spontaneously break free into a gas, even within the liquid itself. when this happens, any energy added gets 'stolen' away by phase transitions,latent heat, rather then raising the temperature. therefore you cant get hotter then boiling, at that temperature depends wholly on the composition of the liquid, regardless of your energy input.

as you say, pure water boils at 100C at STP and pure ethanol boils at 78.4C and mixes will be someplace in between. we never deal with the pure states... because of this, temperature can tell you roughly what %ABV you are at. but in honesty, this is unnecessary in pot stilling. how it actually tastes is what matters so thats what you should judge by. taking temperatures is only really helpful in reflux columns when you are shooting for a specific %ABV (azeotrope)

cheers

[manu de hanoi]

water boils at 100C at STP and pure ethanol boils at 78.4C and mixes will be someplace in between.

that's in short what you need to remember.

[blind drunk]

Hey Elut, it's good that your reading and asking questions. It will all make sense (sort of ) after you've tried a couple of runs. You'll find that this hobby is a blend of theory and practice and each informs the other. Good luck, bd.

[Hawke]

Yeppers, I don't even bother with a thermo on my pot stills. The wash will determine where it wants to go, I just hang on for the ride.
Trying to control the temps on a pot is a lot like a dog chasing it's tail. Might catch up to it once in a while, but what did it accomplish?

[Dnderhead]

""Yeppers, I don't even bother with a thermo on my pot stills""" I don't either.
but I whould thank if someone wanted boiler temps. I whould think it whould go something like this????
:exampol: 75% water//25% alcohol
water .75 x 100c = 75.00c
alcohol .25 x 78c = 19.50c
boiler temperature = 94.50c
as you can see the temperature whould change as alcohol was depleted

ya Iv got tooooo much time/drink on my hands

[blanikdog]

Elut, using a thermometer on a pot still is just not going to help you one little bit. Goinbroke said it all. Worrying about temperatures on a pot still will only confuse you even more. Reading the parent site a couple of times is a good start, but really, a couple of hundred times along with actual practice is what you will need to do. This isn't rocket science, but it isn't something that you will accomplish without a lot more reading, and experience. I still refer to the parent site after years of experience and always find something new. Getting cranky about replies won't help either.

blanik

[IdahoMole]

Elut,
I think a thermometer will be a good idea for you to use, for awhile at least. It will give you one more piece of information to help you understand what is going on in your still. Sure, when you have been doing it for years you will gain enough knowledge that you won't need it anymore, but for now I think it will help with the learning curve. I have been at it for over a year and I still use one. Is nice to glace at it once in awhile during a stripping run. No need for a parrot or such, I just run it up to 98-99C.

Mole

[rad14701]

I still refer to the parent site after years of experience and always find something new. Getting cranky about replies won't help either.

+1

[Fester]

hi, and welcome! i read your origional post and my take on it is that thermometers are ok, but in the mash, well, maybe not so important. the vapor that it being drawn off of the still head is much more important if you want to monitor temp. so if you want temp feedback, that's the place. my newest pot still has no thermometer at all. I use an alcohol parrot mostly (so I can see the proof drop and that gives me a better feel for the cuts).

I just put my hand on the pot from time to time and that gives me a good indication of when the spirit is about to come over. When it starts to flow, i cut back the heat some on a spirit run so i can collect nice and slow. on a stripping run, i leave it running hot and wild and collect just about everythng.

The only thermometer that is really worthwhile is in the vapor stream. It should be very close to the junction of the column and the liebig. This is the vapor temperature of the distillate and it is an indicator of the quality of the spirit that you are collecting.

I don't know much about your mash temp controller. Just know what I know.
Hope it helps a little
Fester

[Elut]

Thanks a lot for all these answers ! That does help a lot.

After all these answers, it sounds like I'm going to put the electric element aside and go with propane burners :p
And sorry, Eternalfrost, looks like I misunderstood your point.

Cheers !

[Fester]

good god no, don't do that. i love my electric element. it is superior to propane and my only regret is that i did not convert to it sooner
Fester

[Elut]

I've always wondered if putting an electric element in contact of high proof alcohol for a re-run was safe ?

[FeralPig]

I've always wondered if putting an electric element in contact of high proof alcohol for a re-run was safe ?

Whether you use propane or electric, you shoul;d be watering down the spirit. I cut to 50%. I am not sure what the more experienced folks suggest.

[Hawke]

From what I've read, most cut to 40%. So, that is where I shoot for. Some of the more experianced potstillers cut to a percentage that will give them the final proof they want to achieve. i.e: Cut to 30% and get 65% in thier hearts. Of course this takes a few runs to establish how your still performs.

[Fester]

i.e: Cut to 30% and get 65% in thier hearts.

What a great tip. I've been buying distilled water because my well water has some calcium and it clouds the spirit. Never thought about adjusting the stripping run to get my barrel strength. Thanks!

[smokerscully1]

I do 'bout everything backwards. I built a pot still and ran it for several months before I came across a stainless steel thermometer. I stuck it in the top of the lyne arm. Interesting but not really nessesary. I keep an eye on it and when it gets about up to 150 degree's ( it in Farenhieght) I know to get ready for the foreshots because it runs from 150 to 180 really fast. The it slows down and steadys at about 190-195--when it hits 196 the tails are starting to come over make sure I switch jars.
I'm sure every thermo is going to read slightly different on different pot stills.

[blanikdog]

...I'm sure every thermo is going to read slightly different on different pot stills.

And also every wash, smokers. I actually have a thermometer on my pot still (which I thought was essential before I learnt otherwise) and it never reads the same. I'd take it out but would mean I have to plug the hole. I find that feeling the heat in the lyne arm is the way to go.

blanik

[Fester]

blanik, you are so right. i can feel around on my still and tell you just when she will start coming over.

[theholymackerel]

The best advice I can give anyone learnin' a potstill is (1) A potstill runs itself, and (2) Just play with it and pay attention.

A potstill runs itself: Pot stills run themselves... you can't "dial" in any specific temperature. The temp it runs itself at is based on the mix of liquids it contains.

A potstill charged with a higher ABV wash/mash will operate at average lower temps, while a potstill charged with a low ABV% wash/mash will run at higher average temps. Make the same exact recipe but the final ABV is a wee bit different? It'll make the still operate differently... this is why a thermometer is next to useless in a potstill.


Just play with it and pay attention: The easiest way to learn a potstill is simply to start usin' it. Try high ABV% washes, try low ABV% washes... learn the difference. Learn how yer still operates, and you'll see it pretty much works the same with everythin' to some degree... the timin' will spread out, or speed up, but you'll see the same pattern over and over and over. Once that pattern is as familiar as the back of yer hand, "cuts" with a potstill will become entirely easy and yer still will almost make 'em for you. You'll be able to take a wee sip of anythin' ya made, and if ya find any fault you will KNOW what it is and avoid it.

[Dnderhead]

you got to do a cleaning run anyway,, make a cheep sugar wash, run it ,, dilute down and run again,again and again.---------

[goinbroke2]

blanik, you are so right. i can feel around on my still and tell you just when she will start coming over.

That's a coincidence fester, I feel around and can tell when she's about to come too.

[Hillbilly Rebel]

I run a traditional pot still. I do not use a thermometer, but through touch I do follow the burn through the lyne arm, into and out of the doubler and over to the condenser. I get excited each time as it works its way through, following it each step of the way! By how fast, how slow or whether the heat retreats, I can monitor what the still is doing and where it is in the process.

As to the point about the temperature, think of it as a light switch. Right now, you may think it is like an off / on switch. Turn it on, (or reach 173 degrees) and the alcohol will all come out all at once with little or no water. This would not be correct. It is more like a dimmer switch, in that you have to keep turning it, (temperature will climb as the mash loses its alcoholic content until it will approach the boiling temperature of water), until it is bright enough for your purposes, (until you have reached your cut off point for your tails).

It is not an immediate thing, it is a gradual progression. As you approach the 173 degrees mark, the abv% of your mash will be the highest. As alcohol vapors will start coming off it will bring not only the alcohol but also other things, (the different components making up the fore shots), including water, with it, but not so much at first. This is when the distillate you capture at the worm will be at the highest in abv%. As the abv% of the mash in your still drops, the higher the temperature will go and also the more water that will come off. Consequently, the abv% of the distillate will continue to drop as it is diluted with more and more water. This will continue until conceivably, all you would have is water left in the still and then the temperature would have reached the boiling point at or near 212 degrees. At this point only water will be coming through. Of course, we all cut this off much earlier when we make the decision as to where to cut the tails.

[rad14701]

That's a coincidence fester, I feel around and can tell when she's about to come too.

Same here, but she makes more noise and moves about more than my still... Heat up to cool down is quicker too...