“Synthetic” dunder.

[Al The Chemist]

On 5/17/2024 at 4:58 AM, Kena1979 said:

@Bolverk I know the column installation is used for Spanish (light) style, not English (heavy body), but still, also in Spanish style, acid mix is used to adjust aroma in some way. We can disable the plates 1 by 1 to do potstill if needed.

I am aiming for a light rum though, with subtle fruity esters; for what I read and tested myself my best guess is that the acid mix is added to the spirit run and let is esterify with sulphuric before running, if you're aiming for this type of rum with this type of installation.

But of course this can be wrong. 

I agree with @Bolverk. If you double distill with 4 plates, even with a heavily wash you will end up with more of a vodka than a light rum. 
I would try running your stripping run in full pot mode (no plates). You can esterify your stripping run if you like. Then if you want a light rum, run your spirit run with 2-3 plates. The fruitiness will depend on what acids you use. If you’re running a plated spirit run, you’ll likely be getting more of highly volatile esters. I’d drop the Butyrin and Lactic and stick to Acetic.

[Silk City Distillers]

3 hours ago, Al The Chemist said:

@Silk City Distillers Would love to get my hands on one of those bottles. It makes perfect sense.  The heads contain a high amount of ethyl acetate, which has a nice sweet and heavy aroma. Its boiling point is so low that it’s usually gone by the hearts. I also don’t cut the heads, though I’ve never tried concentrating them. Any toxicity concerns?

I take it you don't normally drink Wray & Nephew or Rumfire?  Those are 200-500ppm esters.  

Some of the mega high ester rums are 1600ppm.

[Al The Chemist]

5 hours ago, Silk City Distillers said:

I take it you don't normally drink Wray & Nephew or Rumfire?  Those are 200-500ppm esters.  

Some of the mega high ester rums are 1600ppm.

I'll have to remedy that situation.

[Bolverk]

5 hours ago, Silk City Distillers said:

I take it you don't normally drink Wray & Nephew or Rumfire?  Those are 200-500ppm esters.  

Some of the mega high ester rums are 1600ppm.

Rumfire at 500 is definitely at the upper limit of what I can do straight, 200 ain't so bad

[Silk City Distillers]

I would not age out an entire barrel of heads, well, I wouldn't do it intending to bottle it straight, but possibly as blending stock.

Go for it?  What have you got to lose really?  Suspect you are going to let her need to sit for a few years before it starts to really get interesting.

On the point about selecting acids.  Acetic is going to exist in the highest concentration, even in a very typical fermentation.  Acetic esters are the most common, and likely the least sophisticated esters in the bouquet.  It's the other carboxylic acids (propionic, butyric, valeric, caproic, etc) - that start to add some unique and distinctive character, especially with alcohols beyond ethyl (ie. heavy tails alcohols like isoamyl, amyl, isobutyl, n-propyl).

Coconut oil as an anti-foam additive during fermentation and distillation could be very interesting due to the fact that it does contain the C6-C14 acids, and is readily available.  Sugar cane itself does contain similar fatty acids, and when you read the old literature around cane vinegar, cane trash, cane waxes (fats), raises some questions about whether these heavier acids are equally as important.  Coconut oil is a well known "natural" defoamer, so it's a defensible additive.  C12-14 tend to come across as soapy florals, so fractionated coconut oils might be a better option.

[Al The Chemist]

Understood and agreed on the aromatic contributions. I was referring to a plated setup. I've had very little luck getting any of the heavier esters with plates, unless I go very deep into tails. At which point I'm getting too many undesirable flavors, at least for my liking. Ethyl butyrate for example has a higher boiling point than water and is one of my personal favorite additions. Some of the Iso' esters could come through in low hearts, but tend to have a high boiling point as well. 

For more traditional rum distillation (pot, thumpers...) I'd 100% agree. The richer flavors are the heavier ones and they do come up in the churn of the more "acceptable" tails. 

Ethyl acetate has such a low boiling point that you'll get plenty of it even on a "light rum" plated setup. You might actually lose a good portion of it to your foreshots.

[Silk City Distillers]

Some details on ethyl butyrate in fractional distillation:

https://www.mdpi.com/2306-5710/5/2/29

It smears across distillation, likely due to it forming azeotropes.

Isoamyl acetate is an even better example, it has a higher BP than ethyl butyrate, but comes through early in distillation (or even ethyl caprylate/octonoate - with its wicked 400F+ BP).

 

[Al The Chemist]

That's fascinating, thanks for sharing!  

[Brewstilla]

On 5/24/2024 at 6:59 AM, Silk City Distillers said:

I would not age out an entire barrel of heads, well, I wouldn't do it intending to bottle it straight, but possibly as blending stock.

Go for it?  What have you got to lose really?  Suspect you are going to let her need to sit for a few years before it starts to really get interesting.

For sure, the intent isn't the bottle straight, or even blend necessarily. I have spare used empty small barrels, rum heads from last week, and time. Really just an experiment to see what happens with time