Pure acids and ester production

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Pure acids and ester production

Post by RedwoodHillBilly » Sun Jul 09, 2017 12:04 pm

I've searched here and haven't seen a good discussion of adding (to low wines I assume) relatively pure acids for ester production. Most discussions are about getting the right bacterial infections to produce acids i.e lactic acid, butyric acid, etc. to produce favorable esters. I'm wondering if anyone here has experimented with foregoing the bacterial infections and just using the acids directly. The upside that I can see is that it would be repeatable. The downside might be that there are other chemicals that the bacterial infections produce.

While I'm sure that there are scholarly papers on this (in the synthetic flavor industry) I'm looking for direct experience pertaining to our procedures.

Thoughts and discussion?
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Re: Pure acids and ester production

Post by der wo » Sun Jul 09, 2017 1:54 pm

I don't see a reason, why it shouldn't work. For sure not all types of acids will form esters under our conditions (or is anyone able to taste the use of citric acid?).
Intersting would be lactic acid, because wine makers use it for lowering the pH. Perhaps it also adds flavor.
Butyric acid perhaps has the most obvious effect, because the flavor of the acid is so extreme ugly.
Adding vinegar (acetic acid) to rum washes is well described in the Arroyo papers. Ok, it's not pure acetic acid, but probably unrefined cane vinegar.
Formic acid and propionic acid are perhaps possible too.

Of course it's cheating. But if someone will do an experiment, I am very curious.
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Re: Pure acids and ester production

Post by RedwoodHillBilly » Sun Jul 09, 2017 2:09 pm

der wo wrote: Of course it's cheating. But if someone will do an experiment, I am very curious.
Of course it is "cheating", but so what. I use 85% phosphoric acid for ph control when backset doesn't give me enough ph drop, but I can't taste the difference.

Hopefully, someone here has done the experiments. If not, I guess that I'll have to be the guinea pig and do it my self.
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Re: Pure acids and ester production

Post by der wo » Sun Jul 09, 2017 2:25 pm

Phosphoric acid is very strong. I don't think you have used much of it. And the esters of phosphoric acid are not famous for being very flavorful. They are famous for being very poisonous.
Also sulphuric, hydrochlorid and nitric acid will not form nice flavorful esters.

Edit: Welcome guinea pig! :thumbup:
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Re: Pure acids and ester production

Post by Single Malt Yinzer » Sun Jul 09, 2017 2:55 pm

Some thoughts:

- Sour mashing or dunder does this indirectly. Both are acidic and would help produce esters. Most people use it to create a favorable environment for yeast and maybe unknowingly it creates esters for them. This is maybe why people that sour mash say it takes a few generations of to build up the flavor profile well. And with dunder it takes some aging to build it. As the yeast creates alcohol the acids then can form esters. It's not as direct as what you are saying, but it's there.

- I would want to so see if you could find what % of (insert acid) occurs during fermentation. This would give you a base of how much acid to put in the wort. It's not necessary but would make finding the right % faster.

- Along with the previous item, what esters are the best ones to produce (or are targeted) and what acid would encourage their production.

- i also was thinking about adding acids (mostly lactic) directly.

- If it's not commercial production there are no rules, just successes or failures. Home distillers are the ones that push the bounds of what can be done. I'm here to push the bounds ~5 gallons at a time. :)

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Re: Pure acids and ester production

Post by der wo » Sun Jul 09, 2017 3:11 pm

Sulfuric acid does not form fruity esters, but perhaps it is a tool.
We know that dunder pits are pH controlled with lime and sulphuric acid. AND sulphuric acid is the No.1 catalyst for esterification.
From wikipedis "esterification":

Esterification of carboxylic acids

The classic synthesis is the Fischer esterification, which involves treating a carboxylic acid with an alcohol in the presence of a dehydrating agent:

RCO2H + R′OH ⇌ RCO2R′ + H2O

The equilibrium constant for such reactions is about 5 for typical esters, e.g., ethyl acetate.[10] The reaction is slow in the absence of a catalyst. Sulfuric acid is a typical catalyst for this reaction. Many other acids are also used such as polymeric sulfonic acids. Since esterification is highly reversible, the yield of the ester can be improved using Le Chatelier's principle:

-Using the alcohol in large excess (i.e., as a solvent).
-Using a dehydrating agent: sulfuric acid not only catalyzes the reaction but sequesters water (a reaction product). Other drying agents such as molecular sieves are also effective.
-Removal of water by physical means such as distillation as a low-boiling azeotropes with toluene, in conjunction with a Dean-Stark apparatus.
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Re: Pure acids and ester production

Post by RedwoodHillBilly » Sun Jul 09, 2017 3:29 pm

der wo wrote:Phosphoric acid is very strong. I don't think you have used much of it. And the esters of phosphoric acid are not famous for being very flavorful. They are famous for being very poisonous.
Also sulphuric, hydrochlorid and nitric acid will not form nice flavorful esters.

Edit: Welcome guinea pig! :thumbup:

True, I tend to use 30 - 50 Ml of phosphoric acid in a 50 Gal(US) mash to reduce the ph. I don't think that there are esters that I can taste.
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Re: Pure acids and ester production

Post by RedwoodHillBilly » Sun Jul 09, 2017 3:38 pm

Single Malt Yinzer wrote:Some thoughts:

- Sour mashing or dunder does this indirectly. Both are acidic and would help produce esters. Most people use it to create a favorable environment for yeast and maybe unknowingly it creates esters for them. This is maybe why people that sour mash say it takes a few generations of to build up the flavor profile well. And with dunder it takes some aging to build it. As the yeast creates alcohol the acids then can form esters. It's not as direct as what you are saying, but it's there.

- I would want to so see if you could find what % of (insert acid) occurs during fermentation. This would give you a base of how much acid to put in the wort. It's not necessary but would make finding the right % faster.

- Along with the previous item, what esters are the best ones to produce (or are targeted) and what acid would encourage their production.

- i also was thinking about adding acids (mostly lactic) directly.

- If it's not commercial production there are no rules, just successes or failures. Home distillers are the ones that push the bounds of what can be done. I'm here to push the bounds ~5 gallons at a time. :)
I'm here to push the bounds 50 Gal at a time :)

I tend to do a sour mash. I do this for a couple of reasons, 1) to modify ph, 2) for additional flavor.

That being said, I was curious about using relatively pure acids to give a known (and repeatable) ester to the distillate.
John Barleycorn must die.
"and little Sir John in the nut brown bowl proved the strongest man at last.
The huntsman he can't hunt the fox, nor so loudly to blow his horn
and the tinker he can't mend kettle nor pots without a little barleycorn."

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Re: Pure acids and ester production

Post by Single Malt Yinzer » Sun Jul 09, 2017 4:38 pm

RedwoodHillBilly wrote:I'm here to push the bounds 50 Gal at a time :)
Ha - I wish I had that capacity.

If you're going to do a good experiment I would limit the variables. Always use the same grains, same yeast, same methods every time. Using sour mash would be an unreproducible variable unless it's from the same batch for every time. Maybe even forge it for this. Only change the acids that you use. I've been messing with yeasts and dunder and haven't been doing a good job of limiting my variables so I can't say very well what is causing what flavors.

So I see two variables: The acid used and the % used.

Good luck!

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Re: Pure acids and ester production

Post by Pikey » Sun Jul 09, 2017 5:09 pm

Single Malt Yinzer wrote:
....If you're going to do a good experiment I would limit the variables. Always use the same grains, same yeast, same methods every time. Using sour mash would be an unreproducible variable unless it's from the same batch for every time. Maybe even forge it for this. Only change the acids that you use. I've been messing with yeasts and dunder and haven't been doing a good job of limiting my variables so I can't say very well what is causing what flavors.

.......Good luck!
Hell I've been making sloe gin for years - 20 gallons of product maybe ? I've never had 2 taste the same but they all taste great ! - Even my "Easy whisky" - 220 litres batch distilled in 25 litre pot with feints from last time - doesn't taste quite the same after each run - no problem, but that is why the distilleries have professional "Blenders" tasting and blending all day long "

as he said - Good Luck :)

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Re: Pure acids and ester production

Post by Single Malt Yinzer » Mon Jul 10, 2017 4:51 am

Read this link for a chart of Esters and the acids they need to be produced: http://sourbeerblog.com/understanding-esterification/" onclick="window.open(this.href);return false;" rel="nofollow

That should help you figure out what acids you want to test.

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Re: Pure acids and ester production

Post by still_stirrin » Mon Jul 10, 2017 7:00 am

Interesting article SMY. I found this "gem" burried there:
Pitching Rate - Again, it all comes down the production of acetyl-CoA. If a wort is under-pitched, yeast can sense this and undergo rapid growth and multiplication which results in a high degree of acetyl-CoA production, driving esters. Conversely, over-pitching will result in negligible cell growth and very little ester production.
What I find interesting is that many of the home distillers here over-pitch yeast using a less than optimal protocol...pitching unrehydrated yeast or inadequate aeration...hoping that a rapid high Krausen will ensure a healthy ferment. What is suggested in the article is that proper cell count and conditions (including making a proper starter) will generate more of the favorable ester products desired in the finished distiller's beer. Many times I've read of brewers simply dumping in double to 5x the needed yeast and wondering why there is still a lag in activity.

Great article...thanks for the post.
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Re: Pure acids and ester production

Post by Single Malt Yinzer » Mon Jul 10, 2017 7:20 am

You're welcome. Esters have been a under discussed topic in the home and commercial distilling communities. I think that it's due to the somewhat abstract nature and really technical chemical aspects of the subject. We can easily see results on ingredients (barley, rye, corn, sugars), the still, and cuts have. We have control over them. Esters are more magical. You don't add them. You don't know which ones are being formed. The nature of the conversations I've have is that "Hey esters are cool!" and that's as deep as we've gone with it. It's great to see Der Wo, Redwood Hillbilly and others start to really get deep into understanding them better. I see similarities with starch conversion - you tell newbies "let it sit for an hour or so, it'll be fine". I think we're kinda at that stage with esters. We know they are important, we're just starting to scratch the surface to understand them better.

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Re: Pure acids and ester production

Post by der wo » Mon Jul 10, 2017 8:35 am

I will do an experiment. Basic things. I don't plan to add it to my spirits or mashes.

I will have acetic, lactic, butyric and citric acid at home. Also sulphuric (catalyst) and of course ethanol. And propanol (I will not drink it of course). And some stinky feints with perhaps interesting alcohols.

I am very interested in the comparision with or without sulphuric acid. Perhaps sulfuric acid becomes a player in my spirits. Two bottles with Rum low wines + infected dunder, one with one without sulphuric acid.

But it will need time. I fear I don't have time for this the next days.
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Re: Pure acids and ester production

Post by MDH » Mon Jul 10, 2017 9:22 am

Of course you can. This is how esters are produced commercially. The result will likely taste one dimensional, just like anything artificial does.

Fermentation produces a very complex array of chemicals outside of just esters; yeast and bacteria can metabolize all sorts of compounds other than saccharides, they create a diverse array of flavors from these.
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Re: Pure acids and ester production

Post by der wo » Mon Jul 10, 2017 1:49 pm

MDH wrote:Of course you can. This is how esters are produced commercially. Yes. But how long does it need? Does it need heat? The result will likely taste one dimensional, just like anything artificial does. Probably yes. But mixed with molasses or grain flavors perhaps it's interesting.

Fermentation produces a very complex array of chemicals outside of just esters; yeast and bacteria can metabolize all sorts of compounds other than saccharides, they create a diverse array of flavors from these. That's why we know only little about it. All experiments end with "yes, it tastes great".
I will experiment for three reasons:
- I want to know the flavor of the basic esters (ethylacetate, ethyllactate, ethylbutyrate). So perhaps I will be able to identify them in my spirits. So perhaps I will know better, what has happened in my dunder pits or washes.
- I want to know, if it needs sulphuric acid. If it rises the esterification is remarkably, I will add sulphuric acid to all my mashes and washes in future (except neutral washes of course).
- I want to check how much time and heat is neccessary. If heat is absolute neccessary, I will heat up my washes to around 50°C and wait perhaps 1h before I start the distillation. Or I will reflux 100% for 1h and then start to collect. This process of refluxing for a while is described from Arroyo: At the beginning of the evaporation, the ascending alcoholic vapors are totally refluxed back to the column, for a time which is determined largely by the particular characteristics which it is desired to impart to the end product: it has been found that 1 to 2 hours of refluxing is appropriate in most cases. This refluxing increases the esterification and also bauses the accumulation of low-boiling-point constituents at the top plates of the column...(Arroyo: Production of heavy Rums)
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Re: Pure acids and ester production

Post by MDH » Mon Jul 10, 2017 7:34 pm

Sulfuric acid provides protonation, so you don't need sulfuric acid exclusively but it is one of the main reagents. You can use any number of acids. You can try highly concentrated tartaric or malic acid and a food grade dessicant (e.g. anhydrous Magnesium Sulfate) in conjunction. It won't be as fast as sulfuric acid, but I wouldn't use sulfuric for a reason:

When trying to use acids, In basic pot distillation you need to watch out for the esters of certain acids because they are volatile and can make it into the product. I discovered years ago with another hobby that phosphoric acid can and does indeed make it into alcohol based distillate in a basic pot distillation - as its triethyl ester, which I was able to verify through a metathesis with soluble copper (the resulting product was copper phosphate of course).

The same case exists for sulfur acid. It will make it into the spirit.

So, I suspect that in the kind of distillation we are doing, we would not want to use sulfuric acid. Perhaps only in the most niche of situations, such as Vodka production. That's about it.

Heat is necessary because all chemical reactions move faster with higher temperature. But, heating your boiler for a while won't be very efficient. You want the reactants in as much contact as possible. They will be so in the column more than the boiler. Plus, they'll be in contact, I assume, with a large amount of copper or copper mesh. Copper and its oxides are catalytic themselves and will assist in speeding up esterification.
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Re: Pure acids and ester production

Post by der wo » Tue Jul 11, 2017 12:49 am

MDH wrote:I wouldn't use sulfuric for a reason:

When trying to use acids, In basic pot distillation you need to watch out for the esters of certain acids because they are volatile and can make it into the product. I discovered years ago with another hobby that phosphoric acid can and does indeed make it into alcohol based distillate in a basic pot distillation - as its triethyl ester, which I was able to verify through a metathesis with soluble copper (the resulting product was copper phosphate of course).

The same case exists for sulfur acid. It will make it into the spirit.

So, I suspect that in the kind of distillation we are doing, we would not want to use sulfuric acid. Perhaps only in the most niche of situations, such as Vodka production. That's about it.
When I google sulfuric acid mash in my language (Schwefelsäure Maische), I see that all professional distillers here use it for everything (grain, fruit), between 50-100ml per 100l mash.
If you are right, a mixture of ethanol and sulfuric acid should form esters. And if they have flavor and are volatile, I should smell them? Easy experiment. Next week I will do it.
MDH wrote:heating your boiler for a while won't be very efficient. You want the reactants in as much contact as possible. They will be so in the column more than the boiler.
Probably you are right. But because I have an agitator running all the time in the boiler, perhaps it's enough contact.
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Re: Pure acids and ester production

Post by RedwoodHillBilly » Tue Jul 11, 2017 1:49 pm

Single Malt Yinzer wrote:
RedwoodHillBilly wrote:I'm here to push the bounds 50 Gal at a time :)
Ha - I wish I had that capacity.

If you're going to do a good experiment I would limit the variables. Always use the same grains, same yeast, same methods every time. Using sour mash would be an unreproducible variable unless it's from the same batch for every time. Maybe even forge it for this. Only change the acids that you use. I've been messing with yeasts and dunder and haven't been doing a good job of limiting my variables so I can't say very well what is causing what flavors.

So I see two variables: The acid used and the % used.

Good luck!
That is the protocol that I use. I do understand "design of experiments" having been working in R&D for most of my career.

My backset is fairly predictable, considering that I do the same mash protocol. That being said, there will always be some variation. My original question was about using pure (or fairly so) acids instead of (relatively non-repeatable) bacterial infections.
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The huntsman he can't hunt the fox, nor so loudly to blow his horn
and the tinker he can't mend kettle nor pots without a little barleycorn."

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Re: Pure acids and ester production

Post by der wo » Sun Jul 23, 2017 10:17 am

I did a little experiment:

Caution! Experimenting with sulphuric acid and butyric acid is very dangerous. Sulphuric acid is extreme acidic, please wear gloves and glasses. Concentrated butyric acid has a horrible smell, better do experiments with it outside.

20ml acetic acid (20%) + 20ml ethanol (95%)
Smells like vinegar and ethanol. Adding 10 drops sulphuric acid doesn't change something. But after a while the vinegar smell disappears and more and more a glue/foreshots smell comes up. Nothing fruity. Exactly like the first jar coming from a reflux still after refluxing a while. Very nasty.

10ml lactic acid (80%) + 20ml ethanol (95%)
Lactic acid has a bit creamy and fruity flavor already without adding ethanol. Like youghurt drinks. Adding the ethanol makes the flavor a bit stronger. Then I added 10 drops sulphuric acid. It develops more and more a really strong flavor. But it's still very similar to the pure lactic acid flavor. It's a bit synthetical, no specific fruit like apples or plums for example, but interesting complex. I think it fits well in Whisky or Rum.
Edit: The ester of lactic acid and ethanol should smell like coconut (wikipedia). If you have this in mind, you can smell it. But if not, probably it's too synthetical.

10ml butyric acid (99%) + 20ml ethanol (95%)
Butyric acid has pure a horrible and strong smell. Sweat, vomit... After adding the ethanol it instantly changes to a fruity smell. It was still a bit musty, adding 10 drops sulphuric acid removed the musty smell. This was way faster than the two other experiments. The flavor is extreme synthetical and ugly extreme, has no specific fruit flavor, but is complex. A bit like fruit gum. Interesting for me is, that I know this flavor from two fruit ferments, which I mashed very unsterile (sloe and sea buchthorn). But at least at this purity I don't smell a relation to Whisky or Rum.
Edit: The ester of butyric acid and ethanol should smell like pineapple (wikipedia). If you have this in mind, you can smell it. But if not, probably it's too synthetical.


Conclusion:
Especially butyric acid turns to an ester very easy. Sulphuric acid helps esterification (but perhaps other acids too). The flavors are synthetical, I don't know them from nature, but they are complex.

Next experiment will be adding those esters to Rum and Whisky and look how the flavor changes.
Last edited by der wo on Sun Jul 23, 2017 12:04 pm, edited 1 time in total.
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Re: Pure acids and ester production

Post by RedwoodHillBilly » Sun Jul 23, 2017 11:26 am

Der Wo, I'm glad that you started with the experiments. This looks like it could be a very large rabbit hole. The first problem I see is which acids to experiment with. i.e lactic, butyric of course, then I/we should start looking at others like Caproic, Isovaleric, and so on. Once the basic esters have been characterized, then the question becomes how to blend the acids for what type of product enhancement one is looking for. What is appropriate for rum will probably not be appropriate for bourbon.

Like I said, this looks like a very deep rabbit hole. Once I get my current bourbon run on wood so that I have a case or six to drink, I think that I'll do some enzyme converted corn mashes (no backset) so I have a repeatable source of ethanol and low wines to experiment with.
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Re: Pure acids and ester production

Post by der wo » Sun Jul 23, 2017 11:55 am

If we want to make something totally new, then we should try as many as possible acids. I personally have no interest in designing a full synthetic flavored spirit.

If we want to stay in a Rum or Whisky area, then acetic, lactic and butyric acid are the major players. Second important propionic acid and perhaps formic acid. I personally have interest, because I can learn something here perhaps. But I don't think I will ever make for example Whisky low wines and then add lactic acid before the spirit run.
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Re: Pure acids and ester production

Post by rgreen2002 » Sun Jul 23, 2017 12:30 pm

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Re: Pure acids and ester production

Post by der wo » Mon Jul 24, 2017 7:34 am

I also tried to esterificate citric acid. It didn't work. No flavor. Also wikipedia says, that the ester of citric acid and ethanol has no flavor.

I also made a test jar with ethanol and sulphuric acid. I couldn't detect any flavors besides the ethanol flavor.

I diluted the lactic and butyric ester jars to "drinking strength". It didn't change the flavor character.


Adding lactic and/or butyric ethyl ester to Whisky
The best way would be to distill the ester solutions first to get rid of the sulphuric acid. But as long I only smell and not taste the whisky, it's ok with the sulphuric acid.
I took a solid quality but not very interesting Whiksy, it's the Nikka Blended Whisky.

10ml Whisky + 5-10 drops of my lactic ester solution:
The grain spice disappears, the drink gets smooth and a bit fruity. Exactly like I experienced in "my infected wheated Bourbon" thread:
http://homedistiller.org/forum/viewtopi ... 34&t=64615
Yesterday I poured some of the backset to the finished Bourbon mash. I then had around 8% infected backset in the mash.
And, whooo!, the magic works! After a few hours when I sniffed the CO² from the airlock, all the cheesy and meaty smell was gone, but I got mild malty fruity flavors I never had before with my homemade spirits. But I know this aroma, I often taste it in Malt Whiskies. For example Macallan and Auchentoshan have this aroma. And some haven't it at all, Bunnahabhain for example. When tasting Whiskies, I often say, this one is malty and that one is grainy. It's not a quality statement. When I say "malty" I mean a mouthfeel/texture like sirup, when I say "grainy", it has a more coarse mouth feel. Now I realize, my "malty" means lacto-infected.
But this is a Bourbon. I can't remember, that I ever had this aroma in a Bourbon or Rye. So I tasted the three Bourbons I have at home and tried to find it: Makers Mark doesn't have this taste at all, Woodford reserve probably not too, but Eagle rare 10 does have this taste. Not as much as some Malt Whiskies, but it's there. I also tasted it a little in 1776 Rye and much in Mount Gay XO rum.

IMO an improvement of the original Whisky. Or at least a different character, which I like a bit more, with the same quality. I think I am a fan of lactic infections.

10ml Whisky + 1-2 drops of my butyric ester solution:
Bubblegum for kids smell. Exactly like many Irish Whiskies. Tyrconnell for example. I have no idea what those dirty Irish bastards do with their grains, but I have no doubt, their bubblegum smell is butyric acid ester.
I don't like it. I never had it in one of my infected spirits. So here I am still unsure, what exactly is going on in my dunder/backset pits.


Adding acetic ethyl ester (ethyl acetate) to Bourbon:
Here on hd the glue smell of Bourbon is something everyone wants to avoid. But in Bourbon drinkers forums the glue smell is something the real Bourbon connoisseurs really like. So just for fun:
10ml Maker's Mark + 2-4 drops of my acetic ester solution:
Yep. Exactly the glue smell we all know from Jim&Jack.


Next experiment probably will be the same with a dark and a white Rum. But I don't expect something new here. And then infected dunder + alcohol, either with or without sulphuric acid.
Last edited by der wo on Mon Jul 24, 2017 2:20 pm, edited 1 time in total.
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Re: Pure acids and ester production

Post by RedwoodHillBilly » Mon Jul 24, 2017 7:46 am

der wo wrote:But I don't think I will ever make for example Whisky low wines and then add lactic acid before the spirit run.
From your latest experiment, this might be a viable method to add a different character. Quantifying how much to add particular batch of low wines to get a desired result would take some experimenting and experience I would think. Hmmmm... I need more hours in a day for some of these experiments. I think that I'll try to replicate your work as a starting place for me to branch off from.
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The huntsman he can't hunt the fox, nor so loudly to blow his horn
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Re: Pure acids and ester production

Post by der wo » Mon Jul 24, 2017 8:30 am

Yes. This was a success IMO. But currently I am not interested to try it.

If someone wants to pimp his low wines this way, I calculate:
1 drop is around 0.05ml. And my lactic ester solution contains originally 13% lactic acid. 5-10 drops per 10ml Whisky means 0.325 - 0.65ml lactic acid per 10ml 40% ethanol. Perhaps it's a good starting point to add to the low wines the same amount. So per liter pure alcohol of Whisky low wines add between 0.325 x 100 / 0.4 = 80ml and 0.65 x 100 / 0.4 = 160ml pure lactic acid. And perhaps per liter pure alcohol 10ml sulphuric acid. It sounds for me like a bit much lactic acid. But that's what it needed in my experiment... So at least my calculation should convince you not to try something like a few drops lactic acid for 5gal low wines. I would add something realistic in a sample jar, wait 12h and smell. Then you can decide what you will try out for the whole low wines.
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Re: Pure acids and ester production

Post by RedwoodHillBilly » Mon Jul 24, 2017 8:57 am

der wo wrote:Yes. This was a success IMO. But currently I am not interested to try it.

If someone wants to pimp his low wines this way, I calculate:
1 drop is around 0.05ml. And my lactic ester solution contains originally 13% lactic acid. 5-10 drops per 10ml Whisky means 0.325 - 0.65ml lactic acid per 10ml 40% ethanol. Perhaps it's a good starting point to add to the low wines the same amount. So per liter pure alcohol of Whisky low wines add between 0.325 x 100 / 0.4 = 80ml and 0.65 x 100 / 0.4 = 160ml pure lactic acid. And perhaps per liter pure alcohol 10ml sulphuric acid. It sounds for me like a bit much lactic acid. But that's what it needed in my experiment... So at least my calculation should convince you not to try something like a few drops lactic acid for 5gal low wines. I would add something realistic in a sample jar, wait 12h and smell. Then you can decide what you will try out for the whole low wines.
Agreed, I would start with small samples. A low wine run for me are between 25L - 30L. Much too large to screw up on a 1st attempt. I appreciate the numbers, as this will give me a starting point to iterate on.

To do this research correctly, I will probably have to build a small lab still. I can do a stripping run to get 25L or so, then run small samples in the lab still to test. Like I said earlier, this could become a deep rabbit hole if I pursue it to the logical conclusion.
John Barleycorn must die.
"and little Sir John in the nut brown bowl proved the strongest man at last.
The huntsman he can't hunt the fox, nor so loudly to blow his horn
and the tinker he can't mend kettle nor pots without a little barleycorn."

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Re: Pure acids and ester production

Post by der wo » Tue Jul 25, 2017 9:56 am

In the meantime I did the same experiment again, but with other spirits:

First with a simple white Rum, the Captain Morgan White Rum. Also here only the lactic ester solution was good. It needed a smaller dosage, perhaps half, probably because this Rum doesn't have much taste. And like the Nikka Whisky, which lost grain spice, the Captain Morgan lost molasses flavor after adding the lactic esters. Here I prefer the original without added esters.

Then with a dark Rum, the Appleton Rare Blend 12yo. Similar results like with the Whisky. The butyric esters don't fit in even at 1 drop per 20ml Rum. With a very small dosage like 1 drop per 50ml it looses its synthetic fruit gum character, but then it's only a small enhancement of the fruitiness, not something exceptional. The lactic esters are pleasant together with the oak. I like it with oaked Rum as well as with Whisky.

Now after those experiments with the other spirits I think I have a bit more experience and I feel now, that there is also a way to use the butyric esters. But in a way lower dosage than I wrote earlier. It's still strange, on the one hand I am sure my pits have produced butyric acid, but on the other hand I get other flavors...

Anyway, I hope and think it's realistic, that adding acids to low wines instead of esters to spirits will give better results. Mainly because also the other substances of the low wines (for example the higher alcohols) have the chance to react with the acids. And perhaps time and heat will start other reactions ("long chain esters").

I have Rum feints. Perhaps I will experiment with them and the acids.
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Re: Pure acids and ester production

Post by RedwoodHillBilly » Tue Jul 25, 2017 10:28 am

That was my guess from the reading that I did. Adding acids to low wines should allow them to create esters with alcohols that wouldn't be present in any appreciable amount in a finished spirit. Also the heat during a spirit run should help drive the reactions faster.
John Barleycorn must die.
"and little Sir John in the nut brown bowl proved the strongest man at last.
The huntsman he can't hunt the fox, nor so loudly to blow his horn
and the tinker he can't mend kettle nor pots without a little barleycorn."

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Re: Pure acids and ester production

Post by der wo » Wed Jul 26, 2017 1:35 am

RedwoodHillBilly wrote:That was my guess from the reading that I did. Adding acids to low wines should allow them to create esters with alcohols that wouldn't be present in any appreciable amount in a finished spirit.
Yes. But following this theory, adding the acids to the finished washes before stripping would be the best way. Perhaps you have to add more acids this way, but those acids are cheap.
In this way, imperialism brings catastrophe as a mode of existence back from the periphery of capitalist development to its point of departure. - Rosa Luxemburg

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