Why can't I run a pot still by temperature ?

[der wo]

BurntEloi,
do you want higher abv or more neutral flavor?
For a higher abv you need an active reflux still.
For more neutral flavor the simplest way is to dilute and rerun it. To push it to 95% instead of 90% is not much more neutral.

[Kareltje]

BurntEloi,
do you want higher abv or more neutral flavor?
For a higher abv you need an active reflux still.
For more neutral flavor the simplest way is to dilute and rerun it. To push it to 95% instead of 90% is not much more neutral.

Thanks! I am trying to make a real 80 % neutral but after running the heart of a heart I still have very off flavours.
Your remark encourages me to run it again.

[Pikey]

BurntEloi,
do you want higher abv or more neutral flavor?
For a higher abv you need an active reflux still.
For more neutral flavor the simplest way is to dilute and rerun it. To push it to 95% instead of 90% is not much more neutral.

Thanks! I am trying to make a real 80 % neutral but after running the heart of a heart I still have very off flavours.
Your remark encourages me to run it again.

K - on an offshoot of that thumper thread we did a while back - I remember someone saying "Pintoshine" reckoned that 3 passes through a pot with water in the thumper would produce 93% neutral out of pretty much anything.

I know you have the skills to address the 80% aspect by dilution of your charges and that may or may not help - just thought it might

[PS - Pintoshine was a real expert contributor ]

[Saltbush Bill]

I remember someone saying "Pintoshine" reckoned that 3 passes through a pot with water in the thumper would produce 93% neutral out of pretty much anything.

Sounds like a lot of garbage to me , and I think Pint knows better so doubt he would have said that to begin with.

To push it to 95% instead of 90% is not much more neutral.

Are you trying to say that there is very little difference between Neutral run at 90% abv and netural run at azeotrope derwo ?

[der wo]

BurntEloi,
do you want higher abv or more neutral flavor?
For a higher abv you need an active reflux still.
For more neutral flavor the simplest way is to dilute and rerun it. To push it to 95% instead of 90% is not much more neutral.

Thanks! I am trying to make a real 80 % neutral but after running the heart of a heart I still have very off flavours.
Your remark encourages me to run it again.

When you distill the hearts of the hearts, you loose much. I would make all runs like stripping runs (perhaps with a small fores cut), only the last one is a spirit run.

[der wo]

To push it to 95% instead of 90% is not much more neutral.

Are you trying to say that there is very little difference between Neutral run at 90% abv and netural run at azeotrope derwo ?

There is a difference. But the last % need much energy and time. Especially if your column is short and narrow, you will be faster and more successful with diluting and rerunning instead of forcing it to 95%.
In theory 95% has 1/2 of the impurities than 90%. But you need 5 theoretical distillations to get there.
If you dilute the 90% to 45%, you have also 1/2 impurities concentration in the non-acohol part. To get from 45 to 90% again needs only 3 theoretical distillations. 3 vs 5 distillations. And when you dilute more than to 45%, you get much better numbers: For example from 10% to 90% needs only 4 distillations. One less than from 90 to 95%. But you diluted the impurities to 1/9! But this works only, if your column is high enough. And of course the abv in the boiler drops and you will need more distillations to hold the 90%.

[Saltbush Bill]

Or just do it properly and save all the time and effort, build a decent reflux still , one strip run , one spirit run , hit azeo, make good cuts and done.

[der wo]

Ok. Simply do it like all do. It's the safest way. The worst what can happen is, that in a few years the next generation laughs about all those old members, who invested twice the time and energy to get a little higher alcohol number instead of a significant lower impurities number in half the time.

[Bagasso]

https://en.wikipedia.org/wiki/Fractiona ... aratus.svg

About a month ago I was tempted to start a thread about this. I noticed that the search "fractional distillation" in google brought up a bunch of lab and petroleum stills that had no reflux cooling.

Apparently heat management and passive reflux can achieve considerable separation. Typical bunsen burners seem to be equivalent to 200-250 watts, FWIW.

[Pikey]

We'll see how well they perform, when BurntEloi gets his alcohol hydrometer and tests his product. My impression is that he is running too fast to get any real reflux effects - but we shall see and it will be interesting to see what those thngs can do

[Kareltje]

Thanks! I am trying to make a real 80 % neutral but after running the heart of a heart I still have very off flavours.
Your remark encourages me to run it again.

When you distill the hearts of the hearts, you loose much. I would make all runs like stripping runs (perhaps with a small fores cut), only the last one is a spirit run.

I did a stripping run of 60 litres of wash to 3 flasks of about 5,5 or 6 litres: 61,5 %ABV, 40 %ABV and 11 %ABV.
Diluted the heart to 30 %ABV and stilled again to get a standard stock of 80 %ABV, again taking heads and tails. I expected the heart to be neutral as both nasties and wet dogs should not (or hardly) be there, but it definitely is not!
Today I stripped the last flask from 11 to 40 %ABV and it was a real joy to smell the first sample: no trace of the normal nasties!!
I think I will just dilute in portions to max 30 %ABV and make slow spiritruns again.
Or forget about making standard stockbottles of 80 %ABV and be satisfied with 70 % or so. I do not really use 80 % as is anyway.

[Kareltje]

K - on an offshoot of that thumper thread we did a while back - I remember someone saying "Pintoshine" reckoned that 3 passes through a pot with water in the thumper would produce 93% neutral out of pretty much anything.

I know you have the skills to address the 80% aspect by dilution of your charges and that may or may not help - just thought it might

[PS - Pintoshine was a real expert contributor ]

I know Pintoshine from another forum and have high regards for him.
I do not know about taste, about that he might be right. The method is used to give more taste too.
To my surprise my model shows you can indeed make stronger products through a thumper with water. (Or spent lees or the like.) But you have to run several times successively and at the last run a lot of alcohol stays in the thumper!

I have about 10 litres of 80 %ABV I collected this summer and wanted to use coming winter and spring but it tastes not very neutral. So I am motivated to do something.

[Kareltje]

And coming on topic again.
Today I ran a wash of 21 %ABV: 7,5 litres in a boiler of 10 litres, as slowly as my stove does allow: 0,37 kW. My first sample was 74 %ABV, corresponding with about 1,5 trays. So apparently even an insulated upper 1/4 of a boiler can act as a refluxing part of the still.

[Pikey]

And coming on topic again.
Today I ran a wash of 21 %ABV: 7,5 litres in a boiler of 10 litres, as slowly as my stove does allow: 0,37 kW. My first sample was 74 %ABV, corresponding with about 1,5 trays. So apparently even an insulated upper 1/4 of a boiler can act as a refluxing part of the still.

MY Topic - go off it and come back as you like - progression is hugely superior to "Rules"

[Kareltje]

And coming on topic again.
Today I ran a wash of 21 %ABV: 7,5 litres in a boiler of 10 litres, as slowly as my stove does allow: 0,37 kW. My first sample was 74 %ABV, corresponding with about 1,5 trays. So apparently even an insulated upper 1/4 of a boiler can act as a refluxing part of the still.

MY Topic - go off it and come back as you like - progression is hugely superior to "Rules"

I checked: Yes, it is your topic. I thought it was of BurntEloi. Sorry.
It was his problem, though.
I only believe in rules that are useful.

[der wo]

...Today I stripped the last flask from 11 to 40 %ABV and it was a real joy to smell the first sample: no trace of the normal nasties!!...

Then it's probably smeared heads what you don't like normally. Did you once try out to treat the low wines with pH risers? Search the "vodka lab analysis I am pissed" or similar thread. It's off-topic here. So please if you have questions, post elsewhere.

[thecroweater]

Firstly you can not run a pot still based just on temp and there are already a multitude of threads to explain why. The information you get from a thermometer on a pot is not entirely useless but you can't use it to run ya pot still. As for EC yes most will stay in the boiler and if you have a copper riser just about every bit of it will but if you avoid using urea then its really a non issue. EC is a compound formed from ethanol and urea sometimes called urethane and can not otherwise form so the solution is a bit of a no brainer.

[Tater]

And coming on topic again.
Today I ran a wash of 21 %ABV: 7,5 litres in a boiler of 10 litres, as slowly as my stove does allow: 0,37 kW. My first sample was 74 %ABV, corresponding with about 1,5 trays. So apparently even an insulated upper 1/4 of a boiler can act as a refluxing part of the still.

MY Topic - go off it and come back as you like - progression is hugely superior to "Rules"

MY HOUSE so please stay on topic unless its in off topic forums.

[daspooper]

This thread is hugely confusing to me, but that's probably because of my own ignorance; first off, the use of a fractional distillation column implies that this is not a pot still. A pot still, from my understanding, is a boiler with a corner on the top for vapors to move down. A fractional distillation column is a hollow cylinder, typically made of glass, with indented bits of glass called trays (or hollow and packed with copper/broken glass/stainless steel) for the vapor to condense upon. The theory of operation is slightly different from running a reflux column, but not by much. As someone pointed out earlier in this thread, distillation is high school chemistry stuff, or at least it used to be back in the day. I am a more recent graduate, but I experienced using a fractional distillation column in my organic chemistry lab at university where we used it to extract alcohols from a mixture; actually the fist of these labs was to chemically synthesize alcohol and distill it out of the mixture. I distinctly remember the smell of tequila in the lab (maybe from the chemical process we used) and that the best (highest ABV) distillations were from the students who went the slowest and best monitored the temperature at the top of the column. The ABV was measured by a grad assistant who was familiar with how to use a refractometer. That is a lab grade one; not one of those $20 ones you get on ebay.

In the FDC, the vapor condenses on a tray, then another bit of warm vapor passes by; if the condensed liquid contains some bits which are able to evaporate under this influx of heat, they will evaporate and continue climbing the column. The more indentations, the higher your theoretical plates and the better your separation. If you were to run your boiler at maximum temperature, then this wouldn't really work because you would keep increasing the temperature of the column and you would just spit out whatever you boil at the bottom; when you run these slowly you can watch the liquid creep up the column. In fact, it is remarkable to see the difference of ethanol climbing vs water; the water's high surface tension allows the water stay stuck to the walls of the FDC while any of the liquid with a bit of ethanol in it will continue flowing down the column. Think of stepping out of a hot shower and looking at the mirror; that is about what the inside of the column looked like when water vapor was creeping up. The temperature at the top of the column would go from ~78.5 C to very quickly ~100 C as the water made it to the top of the column. I haven't run my FDC in a few years, but this thread is making me want to get it set up again to take some pics to elaborate on these effects.

With the reflux column, you're running your boiler at full power, but you're chilling the column. So as long as you make sure that you have water running through the column at the correct temperature, you will get out whatever high ABV, and it will probably run quicker than the FDC setup; my problem with it is having to readjust the water the whole time to get the same product. The principle of operation is the same; you end up with a gradient of temperature through the refluxing part of the column which provides high ABV at the top and low at the bottom. You do want a metal reflux column because you want to be able to exchange heat from the inside to the chilling water as efficiently as possible; in an FDC, you don't want to transfer heat efficiently as you want that gradient of temperature across the whole length of the column. Reflux is the name of the process given to the condensing-vaporizing cycle that the mixture goes through inside the column.

With the pot still, you don't try to separate any more than the vaporization from the boil is giving you; you're running off at whatever medium ABV, and from what I can tell (I've never run a pot still, so what do I know, though I could if I removed the FDC from my setup and put the corner bit from the top to right on top of the boiler) it seems like through the whole run of hearts you will definitely have some heads left in the mixture because of how vigorously you're producing vapor. There isn't any column for separation, so whatever makes it into the vapor phase at any point will make it into your collection vessel. I assume that there is something I'm missing with the pot still for this to not be the case, but this lack of separation is also the reason that flavors and aromas will survive so readily with the pot still. I would argue that you can run a pot still by temperature, but it is unnecessary as you should be able to tell when you're at tails from the taste of the product. Using the thermometer in the pot still would be more of a binary indicator for whether you should keep going or not as you're dealing with a very complex mixture ie heads, hearts, and tails at the same time so you don't really know what the azeotropic temperature of the mixture is, but again, I've never run one, so wtf do I know, lolol. I guess if you didn't intend on consuming the product then you may want to use the thermometer, but if you're trying to do a separation of oil and alcohol, I would look to a more robust system like a reflux or FDC system as your solvent may pickup scents/flavors if you're not separating them well enough. I guess if you used the same solvent with the same plant, then it wouldn't matter so much, but if you want to get oils out of lavender and orange with the same solvent without mixing the flavors/scents good luck!

I noticed in the discussion of the azeotrope curve that people were talking about the wash composition and temperature, but you need to remember that each time the vapor condenses, it is essentially a new wash at whatever part of the column. So if I had my column set up well, then there would be the wash at the bottom at whatever low ABV, and as you climb the column the ABV of the condensed liquid increases. So each time the vapor condenses, vaporizes and then condenses again, it will be at a slightly higher ABV. This is the reason you can run an FDC by temperature, but you're measuring temperature of the vapor which is condensing and vaporizing again from the thermometer bob where it will pass to your condenser. If you look at the azeotrope curve again, you can see that if you're measuring the temperature of this vapor, you know the ABV of the vapor.

There was a mention in this thread that someone thought copper/stainless steel would work better as packing material in a column as it has better heat transfer; actually that is a negative for this type of system. The faster that the column packing is able to change temperature, the worse your ABV gradient from top to bottom of the column. Consider a metal pot on the stove with metal handles and then consider a glass pot on the stove with glass handles; from my experience, the metal pot handle will quickly heat up and I'll need pot holders in order to safely handle the pot. My glass pot, on the other hand, I am able to hold by the handle even after it has been on the stove for a long time. If I want my whole column to be one temperature, then I would pack it with metal, but I want there to be a significant gradient from the bottom to the top so that only ethanol is vaporizing at the top. This isn't to say that you can't run a FDC with copper packed in (I remember doing this in one of those organic labs, actually), but I would, and do, use a glass indented column for my stated reasons.

Actually, wikipedia does a pretty good job of explaining how a FDC works in small and industrial scales, so if you're super confused about how or why this works, try out their explanation. https://en.wikipedia.org/wiki/Fractional_distillation" onclick="window.open(this.href);return false;" rel="nofollow

This isn't reinventing the wheel; this is using the peer reviewed, best methods wheel, lolol.

PS: after looking back through the thread, I think maybe my confusion is because I misinterpreted the intention of the thread; was the point of the thread to determine if you can run a pot still by temperature? Was it to determine what process BurntEloi uses? It seems like BurnEloi wants to know about urethane in his product, but that isn't what Pikey wanted to talk about, I think. What is the topic of this thread? A demonstration of confusion? Also, it looks like BurntEloi knows what he is doing as far as using his still; woo chemistry sets!

PPS: WALL. OF. TEXT.

[Pikey]

I think you have a grasp of the reflux system as applied to your glass column. Your understanding of the "Coolant management" type of Reflux column, I assume comes from the T500 column explanation ?

We have a number of other reflux systems.

I think it will be interesting to see what your glass column can do with 25 litres of wash and how long it will take to remove the alcohol and what level of purity you can get.

(You won't need a skilled technician to measure your abv for you by the way, just one of those cheap ($6 ) alcoholometers )

Pot stilling Is used for making spirits with flavour and takes a number of variant incarnations. By various methods we can produce flavoursome product at around 60%+ abv, which is then subject to ageing or becomes "White whiskey" etc.

Most of our processes have methods by which we can recover the ethanol from the "Heads" and "Tails"

I did post 2 photos above showing what happens when you DO try to run a pot still by controlling the head temperature, as opposed to running it by adjusting the heat input according to distillate stream. It is not possible to run a pot by temperature, except insofar as when the temp gets up to 100 C it is time to switch off.

[daspooper]

I don't know what "undersanding dropouts" are. I am definitely confused now. : )

[Pikey]

Sorry I editted

[Bagasso]

I don't know what "undersanding dropouts" are. I am definitely confused now. : )

What is confusing you is that around here "fractional distillation columns" always have reflux cooling.

If someone proposes one without reflux cooling they are told that it isn't going to be any different than a pot still. You have seen different which is making you think "that isn't right".

EDIT: Added the word "reflux" to cooling to differentiate from the cooling in the product condenser.

[thecroweater]

Oh boy way to confuse particularly newer guys with horse shit. I don't want to post to much on factional stills as they are off topic for this thread and generally stills more commonly refured to as fractional towers are not used for alcohol distillation but still always use coolant for condensing.
OK so a quick look around would have shown the reasons why you can't run a pot still by temperature. Simplified the compounds in the wash have many different boiling points and depending on the ferment there will be a varying of the volumes of the constituents of those compounds, this can even vary from wash to wash using the exact same recipe as and change to the conditions will produce a different result. Right now not only are the individual compounds higher and lower alcohols etc etc have very different boiling points but combinations of those also have another point of boil depending of the make up of similar boiling point compound volumes. Now a pot still kinda gradually slide for one faction to another and this is why to fairly similar cuts may come off at a different temp from one run to another. Dependent of where the reading is taken there can also be even more variants influenced but outside influences like air temperature humidity etc. Here's the thing, if you could do this everyone would be onto it and would have been a very long time ago. I don't mean to be abrasive but maybe read this post and see if the penny drops
http://homedistiller.org/forum/viewtopi ... 0#p6801645

[Bagasso]

Oh boy

Meh, the person has first hand experience. No amount of eye-rolling is going to change that.

ETA: Just to cover all bases. It might not be the most efficient way to run but it isn't inaccurate to say that an FDC can be operated with heat management and no additional cooling other than passive reflux.

[thecroweater]

OK fella, I'm kind of thinking you are taking the piss now but ..... Yes even my old bumfk no where high school had those 20 mm diameter bunsen burner glass stills, I'm pretty sure you know as well as I why they worked (to a fashion) and why it won't scale up for normal home distillation. Either way its off the discussed topic and not a sensible or realistic concept .

[Bagasso]

Either way its off the discussed topic and not a sensible or realistic concept .

The title is a little misleading. Actually it is the topic of the thread. The setup in the op is not a pot still.

Someone has a lab setup that they believe gave them higher than pot still ABV. Someone else said it wasn't possible because a FDC without reflux cooling can't do that. Someone else chimed in and said that they did just that in his university chemistry class.

It isn't a question of whether it is sensible but whether it is possible.

[daspooper]

Pikey
Yeah, I've watched a few videos with people using various T500 like reflux systems, so I assumed that most were similar in principle to that. From a quick google search, that appears to be correct, but I'm curious to what these other active cooling reflux techniques are.

I wonder with your copper column if there was a problem where the whole column was coming to an equilibrium temperature after a long time of using the still; like I mentioned with the pot on the stove example, that whole column is eventually going to heat up. You said that you held it electronically at 85 C; how did you maintain temperature? If the entire column was at the same temperature and the heater wasn't on or high enough, then I could see having a column of ethanol vapor which was essentially hovering; as the boil wasn't vigorous enough, there wasn't enough pressure from new vapor to push the cloud through the system. Can you measure the temperature of the column at different heights? Maybe if you have an IR thermometer or if you attach a thermometer to the outside of the column with zip ties or something; then we could see if this temperature equilibrium solution I'm proposing is correct or if I'm a dolt. If when the still gets stuck at 85 C, the temperature of the column is the same at the top and bottom (or very nearly the same, say within a few degrees) this may well be the problem. I suppose listening for boiling activity may also be an indicator. I've only used a variac where I am able to adjust the power through the mantle by hand. Then when the drops stopped, I would check the temperature and adjust the variac a bit. A few seconds later I'd see drips again, but I had to do this only once every few hours during a run.

I also wonder how long it will take to get what purity hooch with 25 L; if I'm thinking right, at a high enough product proof it might take days to finish. If I run it a bit faster/hotter, though, it should be on the order of hours, hopefully, lolol. I am also interested in making flavored spirits, so running it as a pot still is something I'm interested in as well.

I realize that for this application a cheap hydrometer will get me a close enough measurement; I didn't see a need back then, and since I haven't started again yet I haven't bought one yet.

How dare you edit and make me look even more confused!

Bagasso
Thanks for that clarification; I guess most people think of metal columns which I do anticipate acting like a pot still if they aren't actively chilled, but a glass column is very different from a metal one.

thecroweater
Obviously the condenser is cooled; I didn't realize we were talking about cooling the condenser. I was only referring to actively chilling the column. I was talking about running a fractional still as that is what BurnEloi is using; it seemed like people were trying to call that a pot still when it plainly isn't.

Why do you think the fractional still won't scale up without active cooling?

Thanks for the thread on running pot stills; it cleared up a bit, but I would point out that kiwistiller does say that temperature is useful in roughly determining when to make cuts with your taste buds and nose doing to fine determination. Obviously this doesn't mean you should solely rely on the temperature for when to make cuts, but it does seem like it would be useful to know what window of temperatures, or ABV if you are measuring that instead as kiwistiller uses both as a rough indicator, to be looking for to make cuts. Should you only use the temperature/ABV? Seems like no. Is it

You didn't mean to be abrasive? lolol starting out with profanities is surely helping that.

[Pikey]

Pikey
Yeah, I've watched a few videos with people using various T500 like reflux systems, so I assumed that most were similar in principle to that. From a quick google search, that appears to be correct, but I'm curious to what these other active cooling reflux techniques are..........

No the principles vary a lot and whilst it is generally tru that most of the commercial ones are based on the same principles as the t500 because they are easy to make and relatively easy to use "just keep the cooling water at xxx temperature"


http://ww.homedistiller.org/forum/viewt ... =1&t=46605

We discovered a little Polish still which one of teh lads bought a few weeeks ago and is NOT a CM still

That little t500 boiler of yours for example would lend itself to having a Bokakob column fitted (A liquid management still, which can also be run close to "Pot mode" )

http://homedistiller.org/forum/viewtopic.php?t=36050

This is a cracking little column - If I had your kit, I would make this column to fit on top. (I wouldn't buy the commercial column)

My copper column was designed as an offset head reflux, but then I found flavour and it has never once been run in reflux mode ! I do have some anomalies within it though. I seem to be getting an element of passive reflux caused by the thin column and the air cooling to it. I also seem to have the temperature at the head of my column around 5-10 degrees C Above the boiler temperature. (Not Proven as yet). It works fine for me at the moment, but one of these days I will make a batch of washes and do some experiments to see what I can see.

I am hoping that you will do that too for us on your little glass column, so we can see what "Lab Equipment" can do and I'm hoping for a little write up so we can investigate it and see what it's constraints and advantages are.

[Bagasso]

Thanks for that clarification; I guess most people think of metal columns which I do anticipate acting like a pot still if they aren't actively chilled, but a glass column is very different from a metal one.

I think that is backwards. Metal would offer more passive reflux but they are not used in chemistry because metals are reactive and glass isn't.

In this post, in a thread about air cooling, Kareltje explains how controlling the heat creates a 2 or 3 cm gradient in his condenser.