Methanol in fruit and feints

[PalCabral]

Hiya Distillers.

In a separate thread regarding how to use the enzyme Pectinase (for fruit mashes and fermentation on pulp), viewtopic.php?t=96267 a question was raised regarding pectinase raising the levels of methanol produced in fermentation. Personally, I believe methanol in home distilling is a red herring. Once methanol is mentioned and a number of people fear for their health and see before them blindness or even death. Truth is far from it. As long as we distillers use proper and natural raw materials, follow the distilling practices that are described on this site, and make good cuts, methanol will at worst cause you a headache the day after you drank your hooch, but so will too much ethanol.

However, while going through one of my favorite threads on fruit brandy production, Pálinka - The Fruit's Spirit, I found a reference to another thread regarding Methanol, which I found very interesting. It discusses aspects of Methanol in distilling that puts an interesting light on how we could do cuts when making fruit brandies, and also on how we could view feints.

Methanol exist in all types of spirits in different degrees, but fruit has by far the highest quantities of Methanol, pears often being pointed to as the raw material with the highest quantity of Methanol.

Methanol per type of spirit.png

It is well-known that Methanol is present through-out the distillation, but many of us, myself included, believe that most of it will be removed with proper handling of Foreshots and a good Heads' cut. However, in this thread it becomes clear that the quantity of Methanol is actually more or less the same through-out the run. As the quantity of ethanol is reduced drastically when we enter tails in the run, the concentration of Methanol increases in relation. I have never thought of it this way and it was an eye-opener for me.

Debated in the thread is that the practice of making cuts for fruit distillates should be more generous for Heads (not fearing Methanol) and more restrictive with the Tails. It also discusses that the practice of using Tails in your feints should be avoided for fruit distillates as it just keeps concentrating the presence of Methanol in your spirit run for every iteration you use your feints. Instead, feints for fruit should only contain Heads. For me, it will change my planned approach for making the cuts for my Apple Pomace Brandy and my Mirabelle eau-de-vie.

I hope you find the thread as interesting as I did.

Methanol Concentrate in the tails according to EC study

[Saltbush Bill]

You still have a lot of reading and learning to do, most long term members here have known that all along, methanol isn't just removed in fores and heads.....its right through the run, including tails.
Probably why Yummy and I bought up the subject of Pectinase and its use in the other thread.
There are more comprehensive threads on the subject if you look around enough.

[jonnys_spirit]

I often use an enzyme called Lallzyme EX-V in my red wine which helps break down the grapes and release “good things” i to the resulting wine.

https://www.lallemandwine.com/en/united ... zyme-ex-v/

They also have other enzymes and I believe Scott Labs does too.

They may have technical data on how using their product impacts methanol production in various musts but I did not see that data on first browse. I bet they do have adequate lab facilities to quantify.

Cheers,
-jonny

[PalCabral]

I often use an enzyme called Lallzyme EX-V in my red wine which helps break down the grapes and release “good things” i to the resulting wine.

https://www.lallemandwine.com/en/united ... zyme-ex-v/

They also have other enzymes and I believe Scott Labs does too.

They may have technical data on how using their product impacts methanol production in various musts but I did not see that data on first browse. I bet they do have adequate lab facilities to quantify.

Cheers,
-jonny

Thanks for the tip, Jonny. EX-V is a pectinase enzyme just like the one I am using, Zymex from Vinoferm. There's no mention of methanol in any of data sheets they supplied.

[jonnys_spirit]

I sent a question to Scott Labs on quantity of methanol produced by this enzyme (and/or any others).. Will update here if they respond..

In any case, I have heard similar - That using these enzymes does increase methanol. I would think that the company selling these enzymes would have performed laboratory testing as a CYA so maybe they can provide further data (or maybe they respectfully decline to provide that data which is probably more likely since they didn't publish it in the first place)...

Cheers,
-jonny

[PalCabral]

I sent a question to Scott Labs on quantity of methanol produced by this enzyme (and/or any others).. Will update here if they respond..

In any case, I have heard similar - That using these enzymes does increase methanol. I would think that the company selling these enzymes would have performed laboratory testing as a CYA so maybe they can provide further data (or maybe they respectfully decline to provide that data which is probably more likely since they didn't publish it in the first place)...

Cheers,
-jonny

Since the methanol is produced by the yeast, maybe the enzyme manufacturer doesn't feel they are obliged to make such studies or share the results of them? I am guessing, of course, but it does seem a bit odd this information is totally overlooked in the technical specs. It is after all well-known that pectinase enzyme breaks down the pectin in fruit, which in turn increses the amount of pectin in the pulp/mash that the yeast can produce to methanol during fermentation. Maybe a case of "I'm not responsible for what others do with the product I provide"?

[jonnys_spirit]

Notes from Scott Labs re: EX-V and similar >

The Mechanism: How Pectinase Enzymes Drive Methanol
Methanol is produced before and during alcoholic fermentation from the hydrolysis of pectins by pectinase enzymes — specifically pectin methylesterase (PME) — which are naturally present in the fruit. More methanol is produced when must is fermented on grape skins; hence there is generally more methanol in red wines than in rosé or white wines. The use of exogenous pectinase enzymes as a winemaking practice will have the effect of increasing the levels of methanol in the resulting wine, in addition to the activity of pectinases naturally present in grapes.

The key enzyme activity responsible is pectin methylesterase (PME), which de-methylates the pectin backbone, releasing methanol. Most commercial pectolytic preparations — including maceration enzymes — contain PME as a side activity.

Baseline Methanol Reference Ranges
Red wines: typically 120–250 mg/L (higher due to skin contact)
White wines: typically 40–120 mg/L
Non-Vitis vinifera wines and fruit wines tend to contain more methanol than pure Vitis vinifera wines
Botrytis-affected wines (e.g., late harvest) can reach as high as 364 mg/L
Non-alcoholic fruit juices naturally contain an average of 140 mg/L, ranging from 12 to 640 mg/L [1]The OIV recommended maximum for red wine is 400 mg/L.[1]

Fruit Musts vs. Grape Wine
The relationship between methanol production, pectin content, and pectinase activity — particularly in apple wine — is described in the literature as "still ambiguous due to the complexity of pectin structure and their hydrolytic enzymes."[2]

This ambiguity is compounded in fruit musts because:

Pectin content varies significantly by fruit type, ripeness, and variety
Higher pectin loads = greater potential methanol release when PME is active
Fruits like apples, pears, stone fruits, and Concord grapes are particularly pectin-rich

What Scott Labs Can and Cannot Currently Provide
Lallemand and Scott Labs does not publish specific quantitative methanol impact data for individual Scottzyme or Lallzyme products at this time. The specification sheets provide enzyme activity profiles (pectinase, cellulase, hemicellulase, protease side activities) but do not include PME activity quantification or corresponding methanol yield data per product.

To quantify the methanol impact of specific Scottzyme products in your production context, the most rigorous path is:

Conduct side-by-side fermentation trials — enzyme-treated vs. untreated controls — and measure methanol by GC-FID at multiple points (crush, mid-fermentation, finished wine)
Factor in the fruit matrix — pectin content and degree of methylation of your specific fruit will be as influential as the enzyme product itself

Cheers,
jonny

[PalCabral]

Notes from Scott Labs re: EX-V and similar >
Cheers,
jonny

Thanks, Jonny.