Equilibrium?

[T-Pee]

This term is constantly used when referencing reflux still operations yet when I try to find a decent description of the term I find nothing.
It's not even in the Glossary.

Can someone please provide some discussion on this part of the process?

Thanks!

tp

[wv_cooker]

In a reflux column as the column comes to temperature and the vapor rises to the top you put the column into 100% full reflux returned back down the column in order to let it equalize or reach equilibrium.

At this time the fractions begin to separate and stack in your column beginning with the lower boiling point alcohols at the top. The longer you allow the column to stay in full reflux the more the fractions compress and stack in the column until the column reaches equilibrium.

The recommended time for this reflux period is anywhere from 15 min. to 1 hour depending on the type of column you use and the type of wash you are distilling.

If you are going for a high ABV neutral you would use longer reflux periods than if you were running a plated column and trying to make a full flavored whiskey.

Hope this helps.

[DAD300]

Equilibrium...search for fractionating stills on google. Like a laboratory (tritium) or oil refinery would use.

When a fractionating (with no reflux) column still reaches Equilibrium, different elements are drawn off from different takeoff points built into the still.

Some would also say that a kind of Equilibrium is being established when a plate still is filling the plates before takeoff.

The term is misapplied to reflux still columns, as we have no different ports from which to takeoff different elements of gas or vapor.

What we do when we go into total reflux for a short period of time is establish a temperature gradient within the column. Because we are refluxing (cooling, condensing and sending the different elements up and down the column), we are in fact (unfortunately) mixing them and have faith that they will separate and come out the product takeoff in the order science establishes. fores, heads, tail,...water.

So if you are at total reflux, you are not establishing element/vapor Equilibrium, but you may be establishing a preferential temperature gradient within your column while you unfortunately mix the fores, heads and send them up and own the column.

I use total reflux until there is vapor at the takeoff port to ensure I don't miss the column filling with vapor and accidentally let it escape. I have this timed now and know it will happen in my rig between 45-50 minutes after boiler heating starts.

I then takeoff the foreshots, heads hearts and tails off in the proper order.

[Ayay]

Equilibrium means everything is in balance and settles to a constant. A reflux column can be in equilibrium at 100% reflux, and at various levels of heat input and take-off. Changing any of the criteria will lead to a new equilibrium thanks to the ability of a reflux column to self equalize or self level. There are many equilibriums during a run.

A reflux column in equilibrium concentrates all the alcohols you give it, it does not separate the various alcohols very well on it's own...it just concentrates all of them according to concentration. The column is stacked with whatever alcohols are driven up and refluxed down, so at the beginning of the run those alcohols are most likely to be foreshots and early heads...but if you drive up tails, they will be concentrated along with the foreshots and early heads, and tails will bleed off in the output of early heads.

A reflux column needs to be driven with some knowledge of a pot stil. Start with an equilibrium of foreshots and early heads...don't give the equilibrium any hearts or tails yet. Let it concentrate the foreshots and early heads and then draw them off. When they are gone, let a new equilibrium happen with the hearts, but no tails. Draw off the hearts. The next equilibrium can only happen with tails. Draw tails off at equilibrium if you want them concentrated, or ignore the equilibrium and strip off the tails without concentration.

Now everything is concentrated to 95% (except tails if you stripped them)...but the hearts are the concentrates that have no heads or tails. Hearts must still be cut by smell, taste, observation, etc. Neither the reflux column nor equilibrium can do this for you.

[Cardinalbags]

To put another spin on what is happening:

Various components if pure will boil at precise temperatures. The lighter the components, the lower its boiling point.

Unfortunately for us, we dont have pure components, we have a mixture of all the components and the mixture will boil based on the properties of the mixture.

Now comes the purpose of the reflux column, to try and separate the components as best as possible.

at the beginning of the boil, the mixture will vaporize and fill the column with vapor. Then the vapor is condensed back to a liquid and drops back through the column. All the components are turned back to liquid, both lighter and heavier components.

Whether the column is packed with scrubbies, mesh, ceramics, or is a plated column, doesnt matter to the physics of it, what it is a location for heat exchange to happen. When the rising vapor meets the descending liquid, heat exchange starts to happen at the contact locations. The lighter components with the lower boiling points will gain some heat and revaporize and start back up the column. The heavier components with higher boiling points will keep falling down the column until they essentially hit their sweet spot in the column or reflux all the way back to the boiler to be re-vaporized. Heat exchange also takes place throughout the entire height of the column wherever the contact locations happen to be. Packed cloumns have a lot more locations for heat transfer than say a plated column does. for this reason, packed columns are more efficient separators of components but that is not always desirable for the product being made

With time, this all stabilizes in the column provided none of the conditions change. Stabilization is a better word perhaps than equalibrium for describing what is happening.

Once stabilized, the foreshots will be concentrated at the top of the column. The reason for taking them off slowly is to not screw up how well the column is stabilized. If they were taken off too quick, the mass flow of product to the top of the still would increase bringing up heavier undesirable stuff.

Once most fore shots and heads are removed, a new condition of stabilization forms with heavier products each moving up in the column and each taking their turn at the top until they are drawn off.

[Maritimer]

Cardinal, stabilization, that's a good word for it.

Just to be pedantic, the verb form is to equilibrate--to bring to or be in equilibrium. To equalize--to make equal or uniform, is something else.

M

[DAD300]

Ayay's version of how to use reflux comes close for me.

A reflux column can not concentrate/separate any "portion" of the alcohol..."foreshots are concentrated at the top." NO, they are condensed and drop through the column into the packing until they are vapor and rise where they tend to mix with the next segment! But if done gently, they may still be the first vapor out of the still.

It is a far better practice to try and remove the fores and heads before trying to use 100% reflux to raise the ABV of the hearts. Just like a pot still will. And just like science has them coming off first.

This is another human fable. Humans want to turn simple science (the idea that the bad stuff comes off first) and make it more complicated (refluxing unnecessarily and tinkering with valves and worrying about temperatures) when science says the bad stuff comes off first, collect it and dump it. Then concentrate the hearts...

[bellybuster]

DAD, just so I understand..
are you taking off fores prior to any refluxing?? I have ran my Nixon as per the instructions given on this site.
I think I understand what you're saying is to run like a pot still for fores removal?? Then into reflux??

[wv_cooker]

I also like Ayay's explanation because he brings one more factor into the mix and that is smearing, which is pushing the still too hard and forcing the next heavier boiling points through the mix. Human nature is the determining factor here for sure, we are all after getting done faster and pushing as hard as we can.

And yes stabilization is probably a better word than equilibrium or equalizing. Stacking or compressing each boiling point alcohol in the column would be the perfect scenario but there are also many other factors that come into knowing how to properly run a still and each still has it's own characteristics that also come into the picture.

[Maritimer]

Mr Pedantic to the rescue. A column in equilibrium is the opposite of equalized. The purpose of equilibrating is to destroy the equalization (that is, when all parts are equal) at the start of the run before the gradient is established.

M

[DAD300]

bellybuster, that's what I want to do, but I have to have the reflux condenser cooled before the fores reach the top of the column, so I'm sure I'm dumping some refluxed fores back down the column. I just try to minimize it.

But, I do believe that if you run full reflux for an hour before any take-off, you have just smeared everything (fores, heads and hearts) together and it will take the column a long time to get back to the natural progression of fores, heads,...

A lot of the pros with pack columns making what they call snowflake vodka are running like this. Take off fores and some heads as soon as the column reaches temp, add, some not total, reflux for heads and reduce it up as the hearts start.

This will be very dependent on your still. I can make azeo with very little reflux, so my sweet spot is 1:1.

Just remember nature and science says, the stuff comes off in an order...try to not screw that up too much.

[rager]

a lot of fantastic info here. im about to build a boka and this is helping a lot.

so if I go this right. "full reflux" is running with out taking anything off. anywhere from 15-60 minutes into heat up. (stablazing )

at this point fores, then heads are pulled off.

so now, is this actually done by the thermometer for fores, heads a and hearts? / temp/ experience . what hasn't been mentioned here in this thread is the temps so much .

I guess the question is how do you know when to start pulling fores, then heads , how do you know they have been compressed and ready to be taken off. and when do you know when your in the hearts. at 95 abv its not like you can taste it off the rig like pot still at 60 abv and how much. that I would expect is different to every wash and rig which I get. these questions are based on running a simple boka cuz that's whats up next in my future .

thanks cheers, ragin ragers dring rum again tonite

[woodshed]

Temps never come into play with cuts when I run. The only time I reference temps is to dial in amps to stabilize column. Cuts are all about touch, taste & smell. Experience is the only successful path to cuts. And lot's of research here.

I don't run a Boka but can say that experience again is what you need. I sneak my fores and heads out before full reflux but could not really tell you how to. I just know that this mash fermented this way and run with a certain protocol will give me the product I desire. That comes from experience. And taking REALLY good notes. The day will come when those notes are a nostalgic reference. You may not need them but will be glad you have them.

Taste I believe is better perceived as a feel. Heads will hit the tongue different than hearts or tails. Even at a high ABV you can differentiate with this technique. Heads up front, hearts smooth on entire tongue, tails creepin up the back. Dial this to your preference and cuts become easy.

[wv_cooker]

a lot of fantastic info here. im about to build a boka and this is helping a lot.

so if I go this right. "full reflux" is running with out taking anything off. anywhere from 15-60 minutes into heat up. (stablazing )

at this point fores, then heads are pulled off.

so now, is this actually done by the thermometer for fores, heads a and hearts? / temp/ experience . what hasn't been mentioned here in this thread is the temps so much .

I guess the question is how do you know when to start pulling fores, then heads , how do you know they have been compressed and ready to be taken off. and when do you know when your in the hearts. at 95 abv its not like you can taste it off the rig like pot still at 60 abv and how much. that I would expect is different to every wash and rig which I get. these questions are based on running a simple boka cuz that's whats up next in my future .

thanks cheers, ragin ragers dring rum again tonite

The question here was what is equilibrium not how to run a still or make the cuts so there shouldn't be a reference to temps and all the other factors of running a still.
Here is a link better suited to answer your questions. http://homedistiller.org/forum/viewtopi ... 63&t=13265

[rager]

fair wv.... but equilibrium does have to do with running a rig. I will I admit may have got off topic with temps . was only trying to contribute . bout to read the link you posted.thanks

read your link... thanks good info .
still got lots to learn

[DAD300]

The OP asked what is the definition of equilibrium? I think the answer is in the above, but the conclusion should be that equilibrium has nothing to do with a reflux column/still.

If you run full 100% reflux you build abv by dropping condensed alcohols for a return trip through the packing, but you also chance smearing the components coming from your boiler. You can't truly separate and stack the components in a reflux still.

[wv_cooker]

fair wv.... but equilibrium does have to do with running a rig. I will I admit may have got off topic with temps . was only trying to contribute . bout to read the link you posted.thanks

read your link... thanks good info .
still got lots to learn

Was in no way trying to bash you or stop your participation was just pointing to info I thought might be pertinent.

[FreeMountainHermit]

Was in no way trying to bash you or stop your participation was just pointing to info I thought might be pertinent.

Darn hillbillies are rude. At least thats what I heard down ta the fillin' station.

FMH

[woodshed]

The OP asked what is the definition of equilibrium? I think the answer is in the above, but the conclusion should be that equilibrium has nothing to do with a reflux column/still.

If you run full 100% reflux you build abv by dropping condensed alcohols for a return trip through the packing, but you also chance smearing the components coming from your boiler. You can't truly separate and stack the components in a reflux still.

I agree with all but the last part of this. Knowing what temps the components want to come off with a particular recipe pulling fores and heads are very straight forward. This is why you pull these before full reflux, makes for a much cleaner separation. Easy to do but you gotta know your still like your lady. What makes her hum?

[wv_cooker]

The OP asked what is the definition of equilibrium? I think the answer is in the above, but the conclusion should be that equilibrium has nothing to do with a reflux column/still.

If you run full 100% reflux you build abv by dropping condensed alcohols for a return trip through the packing, but you also chance smearing the components coming from your boiler. You can't truly separate and stack the components in a reflux still.

I would agree with that for the most part. But I also think some of the old terminology creates the problem. Equilibrium should be stated as stabilization of the column as someone mentioned. And yes there is an inherent possibility of smearing the components back through as shown in many graphs and charts throughout the forums. There is also the differences of a reflux column and a true fractionating column being involved in the definition of equilibrium. So for the simple definition at the hobby level, using a Reflux column we are trying to stack the fractions in the order that they come off. AS for the scientific explanation of them coming off in order of boiling point that is true however they must be separated to do so. And that is why we try to compress and stack them. Otherwise we would have no use for fractionating columns or reflux columns. A simple pot would be sufficient.

Once a column is stabilized then there are many factors involved that can effect it's stabilization, such as too fast a take off, to much heat applied etc. Thus causing the fractions to smear through each other again. Different diameter columns as well as the type of packing such as SPP have an effect on the outcome as well. But the basic definition stays the same as it has been passed down for years. Some of the newer technology such as plated columns and SPP at the hobby level have changed the way we equalize a column and take off product for sure.

[Hound Dog]

Dad, I greatly appreciate you posting about pulling the fores off early! I run a boka. The last run of vodka I made I did take a half quart off just as soon as it was coming up to temp, just experimenting. It just stuck in my head that you really have to be smearing it together if you let it sit and reflux everything prior to taking anything off. But what do I know? I have always read otherwise. Well I have to say, it was an exceptional batch.

Do you think taking more off right away would dip into reducing heads prior to letting it reflux for a while?

Sorry to wander off topic here.....

[8 Mile Hillbilly]

I think I will try Dads system next time I run and see how it is. I usually push the heat hard until the column starts to heat up and then back off so it will climb slowly and then reflux for 20 to 30 min. I think I will try to take off right from the start as this sounds like it makes sense as the fores will boil off first.

[humbledore]

While I am interested in where dad is going with this, wv_cooker captured my understanding in post #2. Full reflux doesn't cause smearing...it is in fact what helps bring more separation between the fractions and compress them. That's why a reflux still compresses heads better than a pot still.

[Hound Dog]

While I am interested in where dad is going with this, wv_cooker captured my understanding in post #2. Full reflux doesn't cause smearing...it is in fact what helps bring more separation between the fractions and compress them. That's why a reflux still compresses heads better than a pot still.

Yes, this is what I had always read and understood it to be. But it just nags at me that I am cooling the vapor and dropping it back down in the column with the other alcohols. I am going to try taking off some early my next couple of goes and see how it works. Then let it reflux for a good bit to start takeoff. It won't hurt either way since I usually end up putting the first quart or two in my feints stockpile as heads. I could be wrong and so could Dad but what do I have to loose by trying? A little liquor? I can always make more! One thing I like about this hobby is playing around for curiosity's sake.

Of course I am in the middle of a new build now and have a kitchen remodel getting ready to start. When that starts, I will have to put stillin' on hold to finish the kitchen or the ol' lady will be up my ass for sure!

[DAD300]

o.k., so here's another step in this process.

As you are heating you boiler and column, put your hand at the top of the column and slowly lower it. You will be able to feel the spot, a very distinct spot, where the vapor has risen to. Do this over and over until you feel the hot point at nearing the takeoff point.

The human hand can stand about 140 deg F. If it makes you retract your hand...it's about 140 Deg F.
No no vapor has reached the reflux coil, yet...or very little. What is that vapor composed of? Fores...fores and heads maybe...all bad.

It's almost 100% fores! Because it has not been condensed and sent back down the column. Let it the hell out before you smear it back down the column.

At this point do you know about how much foreshots and heads you get from your normal boiler charge? So get rid of at least that much and start to reflux more aggressively.

I know my boiler and column take 45 minutes to get first vapor to the takeoff. At about 20 minutes I make sure I have min water going to the reflux col, at about 40 minutes I start putting my hand on the column, I lower the boiler heat to abut 3,000watts, I take off my normal fores 4-6 oz and put it in a fuel jar, I up the reflux ratio a bit and take off 1.5 quarts of pure heads, I set the reflux ratio at my sweet spot, I adjust the cooling water outflow to about 140 Deg F, and take off remaining heads, hearts and tails in the natural progression.

I certainly don't need a thermometer to do any of that. I never attempted to reach Equilibrium in a non fractionating, reflux still column. And I get azeo from 12% wash.

[bonehead]

this is a real interesting thread. there are a few things that i need to try.

[humbledore]

Not saying anyone should not try it, please do. I am just going over it in my mind and discussing.

The way I see it, everything coming up the column even at first is a mix of stuff, and you need that stabilization (equilibrium) to layer it and separate it better. If you do so, that first draw of fores is going to be all fores. If you take the first stuff up the column it is mostly fores, but also other stuff, heads, etc. So now whatever fores you missed will come later, in a mix of heads/fores. Now of course you are still separating heads so it's not an issue. But where I do see an issue is that the same thing will happen with the heads. If not stabilized and taken off slowly you are spreading the heads over a larger volume of distillate in the same way that fores was spread over more overall volume of output. And in my experience that is exactly what happens. When I first started making whisky I made several runs without letting the column reach equilibrium just out of inexperience. I ended up with a larger percentage of the distillate being heads than I would have anticipated.

again, just thinkin' out loud and not saying I'm right.

[googe]

I've tried equalizing for 15, 30,45 and an hour and the difference was not worth worrying about, I now just load the plates and start taking off, taking fores slow, heads a touch faster and hearts faster.

[wv_cooker]

Time for the ah ha moment I see. What Dad hasn't mentioned for those that don't know is that he runs a Manu designed, sliding condenser, VM or vapor management still. He can take off fores and heads like on a pot still as the take off is vapor and below the reflux condenser. Remember different stills and different variables?

On his VM it is quite possible to take off in the method he has explained with out smearing the fractions back down the column. Now let's discuss LM or Liquid management which is the most likely still that most new distillers will end up building outside of a pot still. On a LM vapor must reach the condenser and be changed back to liquid before it can even be taken off. Once it is changed back to liquid at least a percentage returns back to the column either through a tube or through the center of the column itself as reflux. Now I ask the question what happens to that returning foreshots that returns back down the column while you are removing a percentage as well.

It smears back through all the other components that are rising back through the column, thus the reason for stabilizing or equalizing the column. Allowing the fractions to stack and we will call it stabilize for the sake of argument. So now by returning some and taking off some we have the column out of sequence those returning fores are gonna want to go back to the top as lighter alcohols but so are the heads causing the entire process to be unequal ergo the word equalizing or equilibrium.

Now back to the OP's original question what is equilibrium, It is as stated by definition of refluxing your column for a period of time allowing the different fractions of alcohol to stack in the column starting with the lighter fractions at the top. Creating a stable or equal condition for taking them off slowly. That is the simple definition however as you can see there are many different variables that effect how you run your still.

Each type of still whether VM, LM, CM, or LM/VM all have different attributes that will allow you different methods of running them to allow you to achieve the same goals. This is why you are pointed to the different threads here to give you time to grasp an understanding of the principles and theories of how distillation works. Once you have that understanding you are better equipped to choose the type still for the type of drink that you wish to make.

Thanks Dad for your knowledge and input in a very enlightening discussion.

[rager]

if some one could just post some temp numbers that go with this convo it would be great. I know a boka runs much differently than a pot still .not try to side track the thread .but to me... equilibrium has to do with running your rig .why aren't temps mentioned?

I guess im confused about how you make cuts with a reflux still , im well read up on pot stilling. boka is my new project and I want to learn, yoda please teach me the way.....I feel like im missing something here