Eliminating or Trapping Fusel oils

[DAD300]

There is a thread that we feared we were hijacking and I started to push a third topic.

Here...tell me why or why you don't think a prudent, well cut stripping run would trap most of the fusel oils and leave them in the stripping boiler. Then by cutting with clean water for the spirit run more of the remaining fusel would be trapped. Ending in a cleaner spirit!

I don't regularly do stripping runs for two reasons...
1. I have a column that can go fro 12% wash to 95%+ in a single run.
2. I don't currently believe I'd get a cleaner product by stripping first. Faster production by starting with low wines for sure. But cleaner?

However, the discussion of elaborate efforts and expensive contraptions to catch fusel oils at the bottom of a column in a one run scenario, have left me thinking the better method may be stripping runs to create low wines and a spirit run...even if I can make azeo from wash in one distillation.

There have been people here that advised this long ago. Maybe not for the express purpose of cutting fusel, but promoting cleaner taste!

Some have taken to a bubble ball or a single plate below the column, saying it catches most of the fusel. Wouldn't a stripping run do the same thing? Then cut with water for the spirit run catch even more?

[googe]

I now see a cleaner product differently then what I did before using lava rock for example, and lowering my wash ABV. I used to do strips then a.spirit run at 30%, I.thought it was a nice product till I used the lava. First try was a strip and run at 30% using the rock over 3 plates. Then I tried single runs and found no difference in the two. When I did spirit runs with 3 plates, I would do it slow and get around 93%. With the rock I get 90% but it's much cleaner smelling and tasting. I believe it's about the action of distilling, not how it's done, for me anyway.

[Jacksonbrown]

Making cuts on a striping run might create a cleaner product by default but it will also waste a lot of product. Spend the time on the spirit run to do it properly IMO.

The main reason I do striping runs is I don't like the idea of stewing the yeast and whatever else is left in the wash for hours on end if one was to reflux on the first run.
One hard and fast strip to minimise breaking down all that crap then a careful spirit run with precise cuts. In this way the heads and tails are so well concentrated that there is no point saving them.
An efficient column won't let fusels climb to the top anyway as long as the is enough lower BP product still present to hold it back.

[S-Cackalacky]

I'm assuming this would also hold true for a pot stiller. If I were to do cuts for the stripping runs, I could see maybe excluding some of the earlier heads and late tails and getting a much cleaner spirit run from what I collect with the strips. I notice that with my spirit runs, my tails cut normally ends up at around 50% ABV, so I usually stop my spirit run just below that ABV. I can usually also detect that tails smell around that point as well.

So, my understanding of what you're saying is, that to get cleaner, tighter cuts with my spirit runs I would benefit from excluding some of the late tails from the stripping runs. I say, late tails because with a stripping run on a pot still there would probably be considerable smearing from the hearts into the early tails. With a pot still, would that late tails cut be enough to eliminate significant fusels from the spirit run?

Hope this makes some sense,
S-C

[Doogie]

tag (sorry)

[DAD300]

S-Cackalacky...I don't know these answers...there is a big debate going on in a hijacked thread and I'm waiting for the lab guys to step in and tell us the truth. You've asked the question a bit better than I did.

A few years ago, all the lab guys said stripping would eliminate the fusel's, but lately even the guys who strip are trying to "trap" the fusel's in a bubble ball or a tap takeoff under the column. Then they start siting experiments over a hundred years old and how the commercial ops did it way back then.

Standing by

I'm all for better booze and I guess I'll try a strip for low wines just to see, at this point.

[Lester]

There is a thread that we feared we were hijacking and I started to push a third topic.

I wasn't referring to you Dad.

I used to do stripping runs but find it tedious to do so, plus the wasted fuel.

With my column I am able to get a 12% sugar wash down to 1%, and get 95% at the output, but it was slow towards the end. After putting the reboiler beneath the column I saw that I can run much faster specially right after stabilization. And there's no smell of tails in my output as long as I am sensible with the way I run my still. I made a few mistakes at first (tails came out) but I am now aware of when to stop. All part of the learning experience.

I don't do stripping runs anymore.

As for the reboiler being a tails trap, that was not the intention although after the first run the tails were evident in the reboiler, and it was what I reported. Surprisingly for me, this was contrary to a well-held notion that in a tall column, only water comes out at the bottom. From my experience, if I stabilize long enough, alcohol will eventually drip at the bottom of the column and I think that observation will hold true even for a very tall column, if I wait long enough.

[wv_cooker]

@googe
Hi googe, during his trials and experiments with Lava Rock, Mash Rookie commented in one of his discussions that after a few runs he noticed white streaks on the surface of his packing after it had dried in the column. He attributed these streaks to fusels clinging to the surface of the rock and having an effect on the purity of the final product. His method of cleaning his rock was to throw it in his boiler with water and boil it to clean the surface again after a few runs.

@Jacksonbrown
I don't remember whether it was Lester or Edwin, could have been Cardinalbags or Flyingdutchman too, but whichever one it was stated in the other thread that they felt that even though a high percentage of fusels could be held at bay at the bottom of the column that they felt a small percentage escaped up the column throughout the entirety of a run. Mash Rookies findings with his experiments with Lava Rock as packing may just be proving this to be true.

@Dad
I have seen Rad and many others state that water is the best filter, strip and do spirit runs for a cleaner product. Though I have never done stripping runs either maybe some experimentation is in order.

All of these threads of late about refluxing or not refluxing, stacking the column, separating fractions, and removing fusels, I believe are moving us one step closer to cleaner and better products. Thanks to all the folks that are participating.

[googe]

Interesting you say that cooker, yesterday I was playing with my still and noticed white crusty type stuff on the base of the deflag, never had that happen before!. My last run through it was with the rock. I think you've answered my query thanks mate.

[Lester]

Interesting you say that cooker, yesterday I was playing with my still and noticed white crusty type stuff on the base of the deflag, never had that happen before!. My last run through it was with the rock. I think you've answered my query thanks mate.

That's alarming Googe. If you didn't get this white stuff prior to using lava rocks then it's possible that the white stuff is leaching out from the lava rock itself and joining the vapors on the way to your deflagmator. Scary.

[pounsfos]

theres a difference between, clean and pure

just because you're still can reach 95.6% doesn't mean it's a clean product

Odin will tell you all about

it takes roughly 12 plates (physical or HETPS) to get to azeotrope
but that's only to get it there, after that you still have alot of other stuff in there as it still needs purifying

roughly 40 plates will produce a much cleaner product (IE if your still takes your wash to azeotrope without any forced reflux then a forced reflux ratio of 4/1 will give you roughly 40 plates)

thats why we say when doing a spirit run, to go nice and slow as time will give you a better product

and after many tests and "blind studies" i've found, a strip/spirit run will always produce a much better product than just a stripping run, or a spirit run on your wash instead of low wines

but as they say, if you like it, then that's all that matters

[DAD300]

Well, I use SPP and never see any discoloration or buildup on the packing or the SS Scrubbie at the bottom. I do smell the fusel's at the bottom of the column after a few runs (a rinse with hot water to remove). And if I take off below about ~70% the get to the top and takeoff.

But, I also think I get passed them or at least past some oily by products. I can actually get a pint of oily, very light blue tinted crap and followed by something clear and less vile.

I also believe water is a great filter. It is easy to accept the idea of the benefit of a strip and spirit run process. I expect, very time you water the product for the next run you trap SOME fusel's in the water. Just like the water dropping down the packed column takes some fusel's to the bottom with it.

I don't want to invest the time in stripping runs and worked hard to get a column that would go from wash to azeo. But it's worth a try.

[Prairiepiss]

This subject could go back and forth all day long. Problem being. Everyone's tastes and perception of what is clean and what is not clean. Is different. If I say this way works for me. Another person will come along and say it doesn't work for them. More then likely we are getting a very close product. It's just our tastes and perception of what it should be are different. So the only may to definitively figure it out. Would be with chemical analysis. Which most of us can't do or afford. So we are stuck relying on our senses. Which as a group is a big bag of mixed nutz.

Some things I don't think anyone can deny.

The cleaner the product going into the still. The cleaner the product coming out.

Every distillation run done on a particular batch. Will clean it up at least some. To many variables to say how much.

Diluting with clean water for a second run. Will make a cleaner product. Some may not notice it. But how can you deny that it wouldn't clean it up? Common since says it will.

These are my thoughts.

A proper reflux still. Ran proper. Should hold the fusel oils at bay. Until its time for them to come out. Only having problems with inadequate stills and or pushing it to fast.

If chemical analysis was used to build the best neutral making still. I would bet the majority of us would not like the product it made. While some would just love it.

We concern ourselves to much in finding the best method for everyone. When we should really be concentrating on the best method for us individually.

Now as far a stripping runs removing fusel oils. I think this thread would make a few points. Yes it is about a pot still. And yes its about running feints. But that doesn't mean we can not learn from it. To make a reflux still operation better. Since I feel the only way to better find what works to remove things. Is to work with a higher concentration of those things. To see what gives you the most removal.

I personaly found this post by BigR very enlightening. Many others didn't. And I can't see why they can't look past their blinders. And see what good info it really is.
http://homedistiller.org/forum/viewtopi ... 15&t=24388

Sometimes us as humans just have to make things way more difficult then we need to. Thinking science will always work out the problems. I am a firm believer that this hobby is not all science. It's a mixture of science and magic. And you may never be truly happy. If you don't realize that. And keep chasing that rabbit down the hole.

Don't get me wrong. I am all for bettering our hobby. But I also think we can complicate it way to much.

[flyingdutchman]

Maybe some background info might help things along.
For me what I found interesting was a post by Edwin about how the volatility of Fusel oils (and other stuff) changes depending in the ABV of the boiler charge or just liquid in general. http://homedistiller.org/forum/viewtopi ... =1&t=42227 Keeping in mind that these are often the very things we want to control how much if any goes into our final product.

What I found interesting was the very top graph.
What I notice the most is that at low ABV some of the tails seem to be way more volatile than ethanol. But later on at higher ABV they are way less volatile than before.

On the third graph down what is see is a bunch of plates on a giant column (I am thinking continuous still with this image).
Concentrated on the lower plates are some common Fusel Oils/Alcohols. Like i-amyl alcohol, i-propyl alcohol, propyl alcohol.

On the web is a free book at the Internet Archive (Distillation Principles and Practices, Sydney Young) its an old book from 1922 but that doesn't mean it isn't helpful.
https://archive.org/details/cu31924003958216
He makes a clear distinction between how to deal with this stuff between Batch Still vs continuous Stills.
For Batch stills he says

ON PAGE 294..Impurities such as amyl alcohol, for which K' is low, are retained in the still or lower parts of the column as long as possible. Completely to prevent amyl alcohol from passing over into the distillate, it is necessary to maintain a very high concentration of ethyl alcohol on the upper plates of the column, and the alcoholic content of the distillate should be not less than 93-8 per cent by weight........
The amyl alcohol will be present in greatest concentration near the point in the column at which the ethyl alcohol strength is 33-4 per cent by weight, and K' = 1. Towards the end of the rectification, as the
amount of ethyl alcohol remaining in the still decreases, the point at which the alcoholic strength is 33-4 per cent by weight will gradually rise in the column and the distillate will become more and more contaminated with amyl alcohol.

Which to me says on your spirit run on a hobby scale batch still..
1) do a good job equilibrating your column
2) run a reflux ration and heat input rate so that you keep a good equilibrium and keep your product ABV as high as possible
So that then, the tails will come off last. I don't think it matters if you use plates or packing.

that's not to say kicking around the idea of building a fusel oils collector isnt fun to do. Just like kicking around the the idea of building a heads trap/reservoir.

ps I see no reason you couldn't cut them on the stripping run (if your willing to spend the time), I just run mine fast.

[DAD300]

quote...What I notice the most is that at low ABV some of the tails seem to be way more volatile than ethanol. But later on at higher ABV they are way less volatile than before. unquote

This would imply that charging with low wines would keep the column ABV higher and longer. And that that would keep the fusel's in the boiler longer or at least til later in the distillation.

[Jacksonbrown]

By definition tails should be less volatile. Are you suggesting something similar to an azeo is occurring? If that's the case then we can't break the laws of physics with 'traps' etc.

Something to think about, in an efficient column being run properly almost none of the the vapour at the head is being produced at the boiler. Sure it started off there but this is the whole idea of a reflux column. Are people trying to solve imaginary problems or have I completely missed the point?

[flyingdutchman]

Are you suggesting something similar to an azeo is occurring

Yes that is what I think may be happening.
Go to the free book I posted a link to and checkout page 220. See table of azeotropes and notice that i-amyl alcohol forms an azeotrope with water at ~95C which just happens to be ~ 38% ABV for ethanol!

By definition tails are supposed to be more volatile

Well I agree but what if we say tails should come off at the end instead?
It sounds the same but maybe more than one thing is happening that give us the same result.
See look at that first graph of Edwin's. (Now go look at pg 288 in the book I posted, different author same exact graph)
Now that middle line (x axis) is the percent ethanol. The Y axis shows how volatile something is, 10 being the highest, 0.1 being the lowest. The more volatile it is, the faster it escapes the boiler as a vapor. The Now look at the line labeled isoamyl (just above propanol) For what ever reason when the ABV is low, isoamyl alcohol is more volatile than ethanol. Now as the percent ethanol gets higher i-amyl alcohol gets less and less volatile. When it gets to about ~ 38% ABV ethanol they are the same. By the time the ABV of ethanol is ~95%, i-amyl alcohol is a lot less volatile.

So take a wash at say 10% ABV in a boiler. At first I-amyl alcohol is more volatile so it escapes the boiler with some ethanol. But in total reflux more and more ethanol escapes the boiler. The column equilbrates and things settle out by their volatility. From 10% the first plate gives us ~50% ABV (now i-amyl is much less volatile than it was). As we go further and further up the column the ABV of ethanol gets higher and higher. So ethanol keeps climbing and it leaves I-amyl way back down the column.

This would imply that charging with low wines would keep the column ABV higher and longer.

Yes I agree it wont leave the boiler as fast. Then even when it does if we just run it carefully it should come off last. Of course I-amyl isn't the only fusel alcohol check out the book or graphs. There are others and they come off before i-amyl. I say all the more reason to run the column the way it was designed.

[Jacksonbrown]

If what your saying is the case then the way to control it is by controlling what your ferment is producing in the first place. More HETP or bubble plates won't break an azeo.

[Edwin Croissant]

During my limited research I have not come across a clear answer if the vintage distillers made cuts during the stripping run or a low wine run. I may have overlooked, I may have missed the book that explains it all, but I wonder if this was not a closely kept secret. It is not in the best interest of a distiller who makes a perfect cognac, jenever or gin, to have his successful method published. Making cut during a stripping run will make a distinct difference as the fusel oil will be more concentrated in the first part of the run.

Just my two cents, but I think that making cuts in a stripping run is not economical if you are going to use the result to feed a column. Feeding a column with low wine means feeding the column with triple the amount of fusel oil making things worse.

I found another graph in the book “Extracting Bioactive Compounds for Food Products". There is a lot of good information in this book. Google is your friend

Volatility of alcoholic components of wine as function of the ethanol molar fraction.
Source: Extracting Bioactive Compounds for Food Products: Theory and Applications (2009) from chapter 3: Distillation Applied to the Processing of Spirits and Aromas, figure 3.7.

[DAD300]

"The phenonienon of azeotropy can on the one hand be very troublesome, as in the
distillation of dilute alcohol and similar mixtures; on the other hand it offers a means
of “breaking” existing aieotropes and of separating very narrow-boiling mixtures.
By the addition of a foreign compound (known as an entrainer) the formation of a
new azeotcope, between the entrainer and one of the components of the binary mixture,
is purposely brought about; as a result of the larger difference in boiling point the
latter azeotrope can then be separated from the other component."

"At first I-amyl alcohol is more volatile so it escapes the boiler with some ethanol. "

Isn't this the idea of adding Sodium Bicarb to the boiler charge? Although never stated this way, could it entrain the I-amyl alcohol making it less volatile?

Process is usually for an all feints run. Mix a tablespoon per gallon and let set for a week before distilling.

[Jacksonbrown]

Don't think so. that a chemical process. Ionic compound don't really distill. could be wrong though.

More like benzine.

[flyingdutchman]

I don't think we have to worry about breaking azeotropes. Look at the picture Edwin posted which for simplicity I will place here.
My guess is Its a giant commercial still. The lines with numbers on the left are the actual plates (bubble, sieve whatever) from bottom to top. The spirit plate is where they are taking off the ethanol at around 95% would be a guess.
The volatile curve above it may be ethyl acetate like a heads trap.
The curves below it are different fusel oils/alcohols. I would bet donuts for dollars plate 7 has ABV around 38%
Look at what plates they are "stuck at" all we have to do is keep the ethanol ABV ~95% and the usel oils/alcohols stay way down their at the plates with the lower ABV. No need to break any azeotropes just keep the ABV high the rest falls into place like any distillation your used to.

At leasts that's what I think I am seeing.

[flyingdutchman]

If however we wanted to try and eliminate some of the fusel oils from a alcoholic solution, we would have to try and take advantage of some of its physical properties
Young offers this advice on pg 289 of the book I have referenced.....

The fact that the tail products are more readily removed from dilute alcoholic solutions than from more concentrated solutions is
utilised in at least one type of modern still. According to the patent of E. Guillaume the alcoholic liquors to be purified are diluted if
necessary in such a way that the products considered as tail products, e.g. amyl alcohol, may behave during the distillation like head
products relative to the mixture of ethyl alcohol and water. These liquors are then fractionally distilled in a continuous distilling column
of sufficient power and number of plates to enable a large part of the products hitherto considered as tail products to be removed at the
same time as the so-called head products, so that to the bottom of this distilling column there comes only a practically pure mixture of
water and ethyl alcohol.

Now I am not rushing out to try this but it is at least interesting to consider. The idea that it is possible (but maybe not practical) remove heads and tails all at the same time!

Oh and for anyone interested here is the referenced patent..
http://www.google.com/patents/US887793

ps click on the image, then select original image option for a clearer view of his distillation deseign

[Edwin Croissant]

Look at what plates they are "stuck at" all we have to do is keep the ethanol ABV ~95% and the usel oils/alcohols stay way down their at the plates with the lower ABV. [....] At leasts that's what I think I am seeing.

You are seeing it right I found references that "only" 90% ABV prevent the fusel oil from being carried over.

Now ask yourself, what happens when the exit is blocked by the high ABV ethanol in the top of the column?

Show Spoiler

The fusel oil accumulates in the column and eventually seeps through or demixes resulting in a column hiccup.

Source: The alcohol textbook 4th ed. Page 264 fig 9

Now ask yourself how can I prevent this.

Show Spoiler

By doing one of the following:

• By continuously flushing the fusel oil out of the column with excess reflux.

• By containing the fusel oil in a bubble ball of jokmann's relocated gin basket.

• By bleeding the fusel oil off at the point of the highest concentration.

• By Intermittent flushing the fusel oil out with full reflux when the temperature in the top of the column has become to high.

I can't nest spoilers

Thank you for the patent reference for Guillaume's still

[flyingdutchman]

Hey Edwin,
How about hydro separation and the other option hydro selection (extractive distillation)?

[Edwin Croissant]

Hey Edwin,
How about hydro separation and the other option hydro selection (extractive distillation)?

Thank you flyingdutchman

This thread on hydro separation is quite interesting Maybe cold salt saturated water would work better but might damage your still

I looks like extractive distillation is what is going on in ethanol distillation.

The solvent interacts differently with the components of the mixture thereby causing their relative volatilities to change.

To get the heavier alcohols out the water is acting as the solvent to increase the volatility of those heavier alcohols

I found a book as PDF through Google called "Downstream Processing in Biotechnology" by Wesseling and Krijgsman. In chapter 8 page 86 the concept of volatility is explained with polarity (polar and apolar molecules) with no reference to vapor pressures and Raoult's Law. Nice reading

[flyingdutchman]

Yes Hydro separation essentially sounds like a big sepatory funnel (or even Florentine flask). Normally when I use Ethyl Acetate and Water in a sep funnel the Organic (ethyl acetate) forms a distinct layer on the top and the aqueous layer is on the bottom. I am not sure what effect different salts would do to the still but I like the idea of cold in the hopes it reduces the solubility of Fusel oils in the aqeous layer.

Hydro selection using water is how I believe that patent I posted is supposed to work.

[WithOrWithoutU2]

Question....Has anyone tried to do a simple filter of the striped runs with a coffee filter? I've noticed oils comes out on the stripping runs around 25-20% ABV. Personally, I'd like to stripe down to 10% but don't as I want to avoid unnecessary oils. I know people will filter final products through carbon sometimes, but wonder if anyone has simply filtered the stripped runs before the product runs through a couple coffee filters attached to then of a column? I would also think placing the alcohol in the deep freeze would help thinking the oils to make it easy to catch in the filters.

I think I will try it unless anyone has reasons to suggest filtering the stripped runs in this manner is bad or a waste of time.

[Twisted Brick]

I fill a couple of carboys with low wines maybe half an inch below the level of the lip. All of the oils float to the top and and are easily sopped up with a paper towel.

[cayars]

Doesn't get much easier than what Twisted Brick just mentioned. Just wick the oils off the top.