LM Still Operation Instructions questions

[normandy]

Thanks for the instructions. If the first objective is to remove foreshots, ie methanol, why not run the still at methanol temp, 64C (147F) for a while and collect foreshots before increasing the temp ( 78c 172F) to collect ethanol?

[jbierling]

Distillation doesn’t work that way.

[Saltbush Bill]

why not run the still at methanol temp, 64C (147F) for a while and collect foreshots before increasing the temp ( 78c 172F) to collect ethanol?

As a new distiller the first thing you need to get your head around is the fact that you CAN NOT control the temperature at which your wash boils......in short you cant control the temp your still runs at.
Read this it may help you understand.
http://www.kelleybarts.com/PhotoXfer/Re ... gMyth.html

[normandy]

why not run the still at methanol temp, 64C (147F) for a while and collect foreshots before increasing the temp ( 78c 172F) to collect ethanol?

As a new distiller the first thing you need to get your head around is the fact that you CAN NOT control the temperature at which your wash boils......in short you cant control the temp your still runs at.
Read this it may help you understand.
http://www.kelleybarts.com/PhotoXfer/Re ... gMyth.html

Thanks for the response and the ref to the article, yes I have never distilled. In my question I meant the temp of the vapor at the top of the column before condensation and not the boiling temp of the wash. In the instructions no 2 above, it says to maintain the temp of the vapor at 170F by controlling the heating in the still, which is the ethanol boiling temp. I will be using a voltage controller to control the heating element in my still. If I can maintain the vapor temp at 172, then I could also maintain it at 147F first to get rid of the methanol in the wash, not?. But then maybe I am wrong and this can not be done, which is why I asked. Thanks again for responding.

[Expat]

why not run the still at methanol temp, 64C (147F) for a while and collect foreshots before increasing the temp ( 78c 172F) to collect ethanol?

As a new distiller the first thing you need to get your head around is the fact that you CAN NOT control the temperature at which your wash boils......in short you cant control the temp your still runs at.
Read this it may help you understand.
http://www.kelleybarts.com/PhotoXfer/Re ... gMyth.html

Thanks for the response and the ref to the article, yes I have never distilled. In my question I meant the temp of the vapor at the top of the column before condensation and not the boiling temp of the wash. In the instructions no 2 above, it says to maintain the temp of the vapor at 170F by controlling the heating in the still, which is the ethanol boiling temp. I will be using a voltage controller to control the heating element in my still. If I can maintain the vapor temp at 172, then I could also maintain it at 147F first to get rid of the methanol in the wash, not?. But then maybe I am wrong and this can not be done, which is why I asked. Thanks again for responding.

You can't control temp by power input. The vapor temp at the top of the column is a function of purity, which is charge content, packing, reflux rate and takeoff.

[Tummydoc]

Also, methanol content is minimal, and distributed throughout the run, not in the fores. You need to read more and not watch George at barley and hops. Distillation of a mixture of alcohols in water behaves quite differently than pure alcohols.

[normandy]

Also, methanol content is minimal, and distributed throughout the run, not in the fores. You need to read more and not watch George at barley and hops. Distillation of a mixture of alcohols in water behaves quite differently than pure alcohols.

The link given by saltbush above "Zymurgy Bob" , I got to the root of it, and it is fantastic, http://www.artisan-distiller.net/phpBB3 ... 46#p121746 , I am fast reading it. And poor George , yes I have seen some of them vids.

[Yummyrum]

As mentioned , the temp at the top of a reflux still will be determined by what is there at that moment .

Concider you are at the start of the run . The still is in full reflux ... IE ,you are not yet taking off product .
If you leave the still like this , it will seperate the fractions in the column packing with the most volatile being at the top .
The temp at the top will be the boiling point of this most volatile substance . It will be what it is because that is what is there .
You cannot set this temp , it is what it is .

We know when Ethanol is at the top that the column temp will be 78.3°C .
We can even detect that the temp is pretty close to 77.1°C when we are taking of heads due to all the ethyl acetate present at the time .

So in theory we should see the temp reach 56 °C as the Acetone comes off before the Methanol . .... but it doesn’t

The reason is because there s so little Acetone and Methanol compared to everything else that the typical column length we use just cant seperate each minority substance n the space there . If there were substantial amounts f Acetone or Methanol , then we would see the column top temp Indicate the relative boiling points of these as they reached the top .

So while we are taking off foreshots at a drip rate from our typical wash n our typical sized still , the column top temp will be showing a temp which is an approximately average of the small amount of fores and the upcoming heads which by their share volume will be not very far below the foreshots

[cob]

thanks Yummyrum

[normandy]

As mentioned , the temp at the top of a reflux still will be determined by what is there at that moment .

Concider you are at the start of the run . The still is in full reflux ... IE ,you are not yet taking off product .
If you leave the still like this , it will seperate the fractions in the column packing with the most volatile being at the top .
The temp at the top will be the boiling point of this most volatile substance . It will be what it is because that is what is there .
You cannot set this temp , it is what it is .

We know when Ethanol is at the top that the column temp will be 78.3°C .
We can even detect that the temp is pretty close to 77.1°C when we are taking of heads due to all the ethyl acetate present at the time .

So in theory we should see the temp reach 56 °C as the Acetone comes off before the Methanol . .... but it doesn’t

The reason is because there s so little Acetone and Methanol compared to everything else that the typical column length we use just cant seperate each minority substance n the space there . If there were substantial amounts f Acetone or Methanol , then we would see the column top temp Indicate the relative boiling points of these as they reached the top .

So while we are taking off foreshots at a drip rate from our typical wash n our typical sized still , the column top temp will be showing a temp which is an approximately average of the small amount of fores and the upcoming heads which by their share volume will be not very far below the foreshots

Thanks, this was the best and most understandable explanation of why I can not control the vapor temp at the top of the column. I wrongly assumed that that temp is in direct relation to the amount of heat I supply to the still at any time. Thanks a lot.

[Bushman]

Thanks Yummy for your well written explanation only too often we give advice but do not explain why they can’t do it that way.

[Stibnut]

I'll mention another detail that might help drive it home. In most fermentations not involving fruit, there's more acetaldehyde than either methanol* or acetone**. It's an intermediate compound that is one step away from ethanol in yeast metabolism. It's also one step away from ethanol in us - we metabolize most ethanol we drink to acetaldehyde and from there to acetic acid. Acetaldehyde causes nasty headaches and is a contributor to hangovers.

Acetaldehyde boils at just over 20 C or 68 F, yet there's still plenty of it in any yeast fermentation, even if you've got some crazy Kveik strain fermenting at 40 C/104 F. The temp at the still head won't hang at 20 C for any amount of time either. The acetaldehyde will come over with the first few percent of the ethanol right around ethanol's boiling point, and it (plus ethyl acetate and some other nasty congeners, but not methanol) is why we throw out foreshots.

*Methanol is a tricky beast - it's so chemically similar to ethanol that it comes over right along with it, boiling points be damned. And it's more hydrophilic - it tends to stick with water to a greater degree than ethanol, and this outweighs its slightly lower boiling point to keep it coming over right in the hearts barring extremely high rectification, as in columns several stories tall. The reason we aren't all blind/dead is that very little of it is produced in any normal fermentation. Brandies tend to have more than other spirits because fruits contain pectin, which releases methanol as it is broken down. Even then the amounts are small enough that our bodies can metabolize it fine. In fact most fruit juices contain more methanol than most whiskies or other spirits apart from brandies.

**Very little acetone is normally produced. What people think is acetone is usually ethyl acetate, which has a similar solventy odor although a bit fruitier. Its boiling point is just barely lower than ethanol but it gets pushed out faster because it's more hydrophobic. It is harmless but tastes and smells bad, dominating the heads along with acetaldehyde.

[still_stirrin]

Good stuff right there, Stibnut.

It would make a great “cut & paste” sticky....save us all repeating it over and over and over and over....
ss

[zapata]

I will say now that the main point has been driven home that it is useful to not take it too far. Of course any still can be driven by power input, at least to a certain extent. All Cooling Management stills are also power management stills, if'n ya tweak the power knob rather than the cooling knob. And in a LM still more power may increase the temp at the still head if it is overdriving the column/packing, or it may reduce the still head temp if the added power optimizes reflux, column loading and hydraulics. For most people, most of the time, it is true to say they don't and shouldn't run by twiddling the power knob. But that assumes it is set reasonably to begin with. And fine tuning the power can have large effects when dialing in a still.

Similarly, while we can't run a still by temperature in the way most beginners want to, using a thermometer and running the still based off of it is nearly essential for getting the most from a reflux still.

Getting the overall paradigm straight in your head is important, but don't throw the baby out with the bath water. I don't really run by temperature and power management, but of course I sorta do. And understanding that is as useful as understanding why the simplified power and temperature paradigms don't work.

[ThomasBrewer]

Also, methanol content is minimal, and distributed throughout the run, not in the fores. You need to read more and not watch George at barley and hops. Distillation of a mixture of alcohols in water behaves quite differently than pure alcohols.

George is well intentioned, but man, soo much bad and/or misleading information as he doesn't really understand what's going on. His latest series, trying to help two fellows in Potomac, MD. is just hard to watch.

[shadylane]

I can't blame folks for being misled by George
Judging by his comment section, he has a 5 star rating.
He edit's out all who would correct him.

[Brewfiend]

As mentioned , the temp at the top of a reflux still will be determined by what is there at that moment .

Concider you are at the start of the run . The still is in full reflux ... IE ,you are not yet taking off product .
If you leave the still like this , it will seperate the fractions in the column packing with the most volatile being at the top .
The temp at the top will be the boiling point of this most volatile substance . It will be what it is because that is what is there .
You cannot set this temp , it is what it is .

We know when Ethanol is at the top that the column temp will be 78.3°C .
We can even detect that the temp is pretty close to 77.1°C when we are taking of heads due to all the ethyl acetate present at the time .

So in theory we should see the temp reach 56 °C as the Acetone comes off before the Methanol . .... but it doesn’t

The reason is because there s so little Acetone and Methanol compared to everything else that the typical column length we use just cant seperate each minority substance n the space there . If there were substantial amounts f Acetone or Methanol , then we would see the column top temp Indicate the relative boiling points of these as they reached the top .

So while we are taking off foreshots at a drip rate from our typical wash n our typical sized still , the column top temp will be showing a temp which is an approximately average of the small amount of fores and the upcoming heads which by their share volume will be not very far below the foreshots

Yumylmyrum. I'm wondering how much methanol is distributed throughout the wash. I assume they are neglegable amounts and probably safe for consumption?

[Saltbush Bill]

Yumylmyrum. I'm wondering how much methanol is distributed throughout the wash.

Question not aimed at me but here goes anyway
It depends on the wash, sugar washes contain very little if any Methanol at all.
Sugar Heads, Grain Mashes/ washes and fruits contain higher amounts, Fruits on average being the highest in that group.
Sugarcane juice ferments in the style used to make Cachaça are also high in Methanol from what I have read.
There is not enough to really worry about in any of the above.

[NormandieStill]

Yumylmyrum. I'm wondering how much methanol is distributed throughout the wash.

Question not aimed at me but here goes anyway
It depends on the wash, sugar washes contain very little if any Methanol at all.
Sugar Heads, Grain Mashes/ washes and fruits contain higher amounts, Fruits on average being the highest in that group.
Sugarcane juice ferments in the style used to make Cachaça are also high in Methanol from what I have read.
There is not enough to really worry about in any of the above.

From my readings if you really want to make levels of methanol that might be a concern you should be fermenting coffee cherries.