Re-purposing heads into usable alcohol

[iliasm]

There was never a clear document or direction on what do with the heads distillate. From the obvious re-distillation which in my opinion doesn't produce good results, to burning and disposing of them.

Skofis in his 1987 manuscript mentions the work of Dr. Guymon's use of fermentation to re-purpose heads, I summarized my findings and experiment at a recent blog post.

https://blog.dropbit.io/2018/09/25/re-purposing-heads-into-usable-alcohol/

 

[Otto Distilling]

Very interesting, thanks for sharing. What was the ABV of the heads/apple juice before fermentation and then again after fermentation? I was under the impression that any sort of alcoholic mash would make it difficult for the yeast to thrive and could produce off putting congeners. 

[Foreshot]

Thanks for sharing the experiment! Open research like this is hard to come by in this industry. 

For the batch that was fermented with the recycled heads:

1. Did you measure the ABV of the heads?

2. Did fermentation show any effects? Ferment faster/slower? 

3. Open or closed ferment? Temp controlled? 

4. Was the percentage of head/hearts/tails similar to the non-recycled batches? 

5. Was the ABV of the wash similar to the non-recycled batches? (The point is to increase ABV, yes?) 

6. What was the FG? Was it different that expected (attenuation issues?)

7. Any differential to flavor or aroma profile? And save some for review every couple months to see if something happens after a while, good or bad! 

[bostonapothecary]

On 9/28/2018 at 8:57 PM, iliasm said:

There was never a clear document or direction on what do with the heads distillate. From the obvious re-distillation which in my opinion doesn't produce good results, to burning and disposing of them.

Skofis in his 1987 manuscript mentions the work of Dr. Guymon's use of fermentation to re-purpose heads, I summarized my findings and experiment at a recent blog post.

https://blog.dropbit.io/2018/09/25/re-purposing-heads-into-usable-alchohol/

 

I have James Guymon's paper somewhere if you want it. It is a very cool technique and supposedly created a 2% economy on vodka production that may have been worth startling money over the years.

[bostonapothecary]

James Guymon - Some results of processing heads by fermentation (PDF) This link is for his original pilot plant article, but there is also another later one published by the American Chemical Society that I'll grab next time I'm at MIT.

The Elie Skofis interview is available here where I index the beverage industry parts of the California Oral History Project.

Skofis also delivered a really informative James Guymon lecture in 1983 and I've digitized it here.

With the birectifier, in the first fraction of finished spirits, you don't really notice acetaldehyde because in spirits that are cut well, ethyl acetate dominates on a sensory level. However, I just started analyzing vermouths and on Noilly Prat, wow was there some nasty acetaldehyde. This was probably because of how they torture their wine by madeirizing it. The interesting thing is how all the other features allow our attention to metabolize it and it is not dissonant and gnarly. Many dessert wines hid scary amounts of acetaldehyde.

The oral history of Antonio Perelli-Minetti is a thriller with him even sitting down to have lunch with Poncho Villa. A technique he used as a hustling wine maker was to buy spoiled wines, presumably oxidized with high acetaldehyde, and then to referment them in volumes of new wine which somewhat rehabilitated them. I think that is where Guymon got the idea. There was a known folk wisdom about the concept.

[iliasm]

Thank you @bostonapothecary for sharing the documents and the lecture, there was also mention of further research that was fallen through in terms of bringing them forward as a book.

On 10/4/2018 at 6:48 AM, Foreshot said:

Thanks for sharing the experiment! Open research like this is hard to come by in this industry. 

For the batch that was fermented with the recycled heads:

1. Did you measure the ABV of the heads?

2. Did fermentation show any effects? Ferment faster/slower? 

3. Open or closed ferment? Temp controlled? 

4. Was the percentage of head/hearts/tails similar to the non-recycled batches? 

5. Was the ABV of the wash similar to the non-recycled batches? (The point is to increase ABV, yes?) 

6. What was the FG? Was it different that expected (attenuation issues?)

7. Any differential to flavor or aroma profile? And save some for review every couple months to see if something happens after a while, good or bad! 

1

@Foreshot ABV of the heads was at an average of 75%, fermentation started slow possibly due to the ABV but completed with no issues. I did add extra nutrients and a second round of yeast additions mid-way to help finish. It was an open top fermentation, yes in terms of the percentage of ABV it was the same as my normal wine fermentations, although this was apple based, which was my first time doing so not a lot of experience there.

In terms of aroma and flavor, I did not notice anything when the fermented cider was finished or distilled. With that said once distilled I did my normal cuts, also the final product was destinated to be a brandy liqueur base so if I was to produce an apple brandy for example, I would have been more careful with the amount of heads added.

Overall, in my opinion, this was successful but it needs further refinement. A better understanding of the fermentation and nutrients and more experiments to figure out a good ratio of heads to fermented mash, although the links that @bostonapothecary shared are a good resource.

 

 

 

[bostonapothecary]

Its really awesome to see this brought to life. I'll be sure to get that second paper in case there is something helpful in it. MIT computers have quick access to anything hosted by the American Chemical Society so if anyone comes across a paper they need, him me up.

My understanding is that UC Davis has special collection of Guymon's papers and I always wondered if there was anything especially cool in there. I have his 1970's course syllabus which includes a lot of hand outs. UC Davis uploaded videos of all his distilling course lectures on youtube and I have a bunch annotated somewhere but I never found time to write up a post. It appears the Davis distilling course got high jacked by the petroleum industry. They strayed from fine spirits production and went theory heavy so the petro industry could poach smart students. There are still some absolute gems in the series and I remember a guest lecturer gave a pretty amazing talk on how distillers malts differ from brewers malts. There are some great recollections of just after prohibition as well as the war years, red wood trunk wooden stills, etc.

[iliasm]

That would be great, I'm sure there some good information on those documents as well. I also plan on doing a test from the document you shared above that mentions the use of heads towards the end of the fermentation (3.8 Brix) since I have a ferment that's almost done, although his recommendation is to add it mid-level when the fermentation is the most vigorous, so that will be done at the next fermentation and compare results.

Cheers,

-ilias

[Silk City Distillers]

Why reintroduce the heads as a single dose?  I would imagine the impact to yeast stress could be minimized by metering in the heads over a 12 or 24 hour period.

 

 

[bostonapothecary]

The only thing I'd caution about using this technique is that it may mess up your ability to make optimal heads cuts in full flavored spirits. This is because the technique targets aldehydes but the limiter for most spirits is ethyl acetate. In the opening paragraph he does mention it can reduce ethyl acetate to a degree.

You could totally tackle these challenges, but you'd absolutely need an analysis solution to get you there. Every new American spirit I analyze with the birectifier has wacky first fractions relative to established role models. Most are too light on ethyl acetate. The birectifier gives a pretty clear organoleptic way to assess ethyl acetate without performing a titration. You can even take the first fraction where the majority of it collects and perform an exhaustive test of systematic dilutions to weight it.

If you could tackle that, the technique may be a meaningful piece of the puzzle of reducing ordinary congeners. A lot of the Arroyo advice adds up to making better spirits if ordinary congeners are reduced in the ferment so you can distill much lower and cut away less.