Brewing - getting rid of methanol

[shroomeryguy]

Swim has just fermented some yeast/sugar/potato mash, and some sugar/yeast mash, just to make sure (" Swim does not want to go blind") since methanol boils in a lower temp, would collecting the mixture at ethanol's boils temp 78C get rid of all the methanol, if not please tell swim how
and one more thing is there ethanol coming out when the temp goes higher than 78C?

[bcubed]

SWIshroomeryguy,

Welcome to a fun and potentially economical (depends on usage rates) hobby!

Rest assured that you haven't produced a toxic brew: methanol concentrations are minimal, assuming good practices, and even then are generally associated with fruit-based washes (i.e. high in pectin). In things like beer, for instance, they don't even make an attempt to remove the traces of methanol.

To produce a high-quality liquor, however, generally the first fraction (depending on the "selectivity" of the still, but never more than the first 10%) is tossed out. Also, don't get greedy! Toss out the last 1/3 of production, or whenever the taste is "off" (sorta rancid), as that contains "fusil oils," or higher alchols/esters/whatever, that won't kill, but will produce nasty hangovers in volume. (Actually, save the dregs so that you can taste a few ml and learn to ID the "tails" by taste.)

I guess what I didn't mention is that you won't ever distill just methanol (or ethanol, for that matter): it'll be a mixture of water, ethanol, and a bunch of other chemicals--all the stuff that makes booze taste like more than just ethanol+water. Multiple distillations (or a fractionating cloumn, that just allows you to distill multiple times in one go) produces "purer" ethanol: higher proof, lower flavor. Personal tastes vary.

[shroomeryguy]

okay thanks I just wanted to make sure

[st sam]

^^ a lot better than what im going to say.

However, if you do still want to get rid of methanol. Put it in a pan with a thermometer and heat it to about 68-72. Methanol boils at 65 so this should get rid of methanol and not ethanol. the methanol would just go into the atmosphere.

Boiling it at 78 and collecting it would give you both ethanol and methanol.

[Potter]

Understand that if you do attempt distillation to clean out the methanol, and mess up your procedures, you will concentrate what may have been a safe booze into poison.

Best to have it fresh and not risk it. Remember, the ethanol will use up the liver enzymes, so the small amount of methanol passes through before turning toxic, but if you concentrate everything down, you risk the methanol being turned into formaldehyde and fumeric acid, both very bad for you.

[bcubed]

I didn't want to get this far into the minutia of distilling, but I also don't want anyone getting any ideas about distilling methylated spirits to drink.

If you take a mixture of methanol and ethanol, the methanol WON'T all boil out at the BP of pure methanol! What will happen is 1. the mix will boil somwhere between the two BPs, based on respective concentrations, and 2. The vapor will be comparatively richer in methanol, and the remaining liquid poorer in methanol.

To know EXACTLY how much methanol would remain, you'd need to know a whole bunch of info, as well as have a sure-fire way to test the remaining undistilled product. I'm not saying it'd be impossible; I'm saying it would require so much accumulated smarts that you'd be smart enough to know how bad of an idea this is!

You'll never get every molecule of methanol out of an ethanol mix, any more than you'd ever get the last ethanol molecule out of some fermented potatoes. However, when starting with a very modest amt. of methanol, as is the case with fermentation, tossing the first 10% collected will be plenty sufficient to reduce concentrations to "generally recognized as safe" levels.

(Oh, I mean "you" in the plural, indefinite "any youz guys" vs. "you--yes, you reading this at IP such-and-such", 'kay?)

Reputation Comments on this post:

Thanks for clearing up a couple things on boiling points!

[Sven99]

The worst possible consequence is that your spirit will have the same methanol to ethanol content as whatever you were distilling from. Which isn't anywhere near enough to hurt you. Prohibition era Methanol-lore mostly comes from shady bootleggers topping up their moonshine with methanol to increase profit - at which point it does become dangerous.

Throw the first 50ml for each 5 gallons of mash away if you're using a reflux still, or 100-150ml if using a pot-still. If you're doing multiple distillations of the same mash, throw it out on the second run as this will concentrate the methanol towards the beginning of the run and get rid of more of it.

Reputation Comments on this post:

	exacltly what I was looking for, a ratio between product and methanol.
	good call on a common misconception. thanks for clarifying that better

[cra$h]

a, great info. Definitly got swim a little more confident in his first expidtion of distilling. He's only dealing with a 1/2 gallon still, but it's a good place to start. thanks a lot!