Safety of the product

Ethanol Toxicity

The greatest risk to anyone who drinks alcohol is the stock-standard pissed-as-a-newt high school student style of alcohol poisoning. It tends to come from our culture of binge drinking, rather than the more moderate consumption sometimes observed in Europe. Jack has the details ...

The fatal dose of ethanol is 300-400 mL of pure ethanol (600-800 mL of 50% spirits), for the average adult if consumed in less than one hour.
Chronic users develop a tolerance to ethanol. Ethanol depresses the central nervous system irregularly in descending order from cortex to medulla, depending on the amount ingested. The range between a dose that produces anesthesia and one that impairs vital functions is small. Thus, an amount that produces stupor is dangerously close to a fatal dose. Effects are potentiated by concomitant ingestion of barbiturates and other depressant drugs.
Intoxication levels (broadly) are found in this manner:

  • Mild (Blood alc content 0.05%-0.15% - one fourth of the people at this level are clinically intoxicated) results in decreased inhibition, slight visual imparement, muscular incoordination, and slowed reaction time.
  • Moderate: (BAC: 0.15%-0.3% - 50 to 95% of the people at this level are clinically intoxicated)- results in definite visual imparement, sensory loss, muscular incoordination, slurring of speech.
  • Severe (BAC 0.3%-0.5% -fatalities begin to occur in this range)-marked muscular incoordination, blurred vision, approaching stupor.
  • Coma (BAC above 0.5% - death is common in this range)- Unconsciousness, slowed respiration, complete loss of sensations.

Treatment of acute poisoning begins with the removal of unabsorbed ethanol by gastric lavage with tap water or by emesis (induced vomitting). The airway must be kept clear- artificial respiration may be needed. Give 2grams of sodium bicarbonate in 250ml of tap water every 2 hours to maintain neutral or slightly alkaline urine, avoid administration of excess fluids. Avoid all depressant drugs. In the presence of hypoglycemia, give 5-10% glucose intravenously plus thiamine, 100mg intramuscularly. Hemodialysis is needed if the blood ethanol level is above 5mg/ml. Survival for 24 hours is ordinarily followed by recovery.

Fire

The next greatest risk to distillers is that of fire.
You're producing a liquid which is on a par with gasoline with flammability, yet doing so around heating elements (or even gas flames).
Make sure that there is no way the still can build up pressure - say by blocking the outlet piping, or accidently crimping it?.
Make sure your equipment is in good and clean condition when you use it.
Be sure the packing material is not clogged up, or blocked.
Make SURE that there are no leaks.
Don't bury the outlet tube under the surface of the liquid level in the collection jar, rather have it dripping into it openly.
If using gas, keep the collection jar quite away from it.
Don't set up your collection jars so that they are easily knocked over, and cap them when not in use.
Keep your area well ventilated.
And never, NEVER, NEVER, leave the still unattended.
At all times keep a fire extinguisher close.

Will I go Blind ?

A big fear for many new distillers is that they are risking poisoning themselves with methanol - a toxin that can cause blindness. There is little basis for this fear however; if formed, it is only in small amounts, and can be easily discarded with the "heads" collected first (see here) during distillation.
A simple (but effective) rule of thumb for this is to throw away the first 50 mL you collect (per 20 L mash used) for a reflux still. If using a potstill, make it more like 100-200 mL. Do this, and you have removed all the hazardous foreshots, including the methanol. To get a really clean distinction between the foreshots and the rest of the alcohol, increase the reflux ratio to the point where you're taking off this first 50 mL at a very slow rate (eg 1 drop per second). This will give a very stable equilibrium within the column to allow all the methanol to collect at the top of the column and be in this first portion.
If you are doing a double or triple distillation with a pot still, don't worry about removing the heads & tails on the first pass. Wait for the second run, when they are more distinct & easier to seperate. Once you have removed them, they are gone, so much less will need to be discarded from the subsequent runs, other than that dictated by taste, and any improved seperation that may result from running a more pure distillate through the still.
How dangerous are the various fuseloils ? I've got some of them listed below.
The ones with toxicity data listed are ...

  • Methanol : usual fatal dose 100-250 mL
  • 1-Pentanol : LD50 (rat) 3030 mg/kg
  • 3-Pentanol : LD50 (rat) 1870 mg/kg

Compare this to the amounts present in distilled spirits. The data in Wheeler & Willmotts "Spirits unlimited - a complete guide to home distilling" gives :

  • Home distilled spirit (untreated): methanol 0.0067%, ethanol 99.632%, fusils 0.361%
  • Commercial vodka: methanol 0.013%, ethanol 99.507%, fusils 0.48%
  • Poor quality home distilled spirit : methanol 0.0186%, ethanol 98.453%, and fusils 1.528%

If you're talking about untreated spirits as being dangerous, then to reach the LD50's that are published, you'd need to consume 149 L to be affected by the methanol, or for a 90kg bloke, about 58 L for the pentanol, from the "good" homemade stuff. That would be one hell of a session ! Even on their "poor quality" brew you'd need 11 L for the fusels. Stock standard pissed-as-a-newt high-school-student alcohol poisoning is the greater problem.
Now their "home distilled spirit" was at a time when their best design was only putting out roughly 75% pure ethanol. What's the story from like a Nixon-Stone or Euro doing 95%+ purity ?
Compare that to the levels of methanol etc that you get via other sources ...

Methanol & Other Impurities

Methanol is formed when fermenting beverages high in pectins - eg grapes and berries. Starting with a grain or sugar based wort, in a clean fermentor with a yeast culture from a well aereated source will result in small/none formed.
Carl from Hambletonbard (makers of Alcotec yeasts) details ..

Methanol, you will typically get around 2 or 3 parts per million (or milligrams per litre if you prefer) of methanol produced during fermentation of a standard 6kg type Alcotec - this is extremely low even compared to commercial products. We don't have a great deal of data on methanol because whenever we have tested for it we have got extremely low results.

Mike explains about the pectin ..

The methanol comes from the pectin, which mainly composed of methyl esters of galactose. When pectin breaks down, by enzymes introduced by microorganisms, or deliberately introduced, the methyl esters combine with water to produce methanol, so the aim should be to leave the pectin well alone if you can.
I think Jack would agree that what he means is that fermenting at a high temperature, or adding pectin enzyme, or trying for an abv higher than 12% all increase the risk of methanol being produced, so his advice about low temperature fermentation, adding no exra enzymes, and a target lower than 12%abv is all good stuff.

You are already being exposed to methanol from other sources. Some fruit juices are naturally high in methanol - for example apple juice can have 0.2-0.3% methanol, or if derived from pulp by enzymatic degradation, the levels can be 2 to 3 times higher.
Johan found ..

In orange juice contains 10 to 50 times as much methanol as sugarmash.
The lethal dose of methanol is at least 100 ml that is equal to about 80000 mg or you need 27000 liters of mash at least to get that amount.
also from the webpage: "Dietary surveys have shown that an extreme consumer of orange juice drinks slightly over 2 litres/day. The estimated maximum intake of methanol based on this consumption would be 455 mg for a 60 kg adult which is below the maximum advisory intake of 600 mg per day for a 60 kg adult, recommended by the Department of Health."
So if we stay under 600 mg per day we are safe, that's the same as 200 liters of mash per day or about 70 liters of 40% alcohol per day if you weight is 60 kg.
total amount of methanol in mash expressed in ml is about 0.1 ml = nothing.

Jack comments ...

The Long Ashton Research Station did some studies that showed that ciders and apple juices clarified with pectic enzymes are higher in methanol due to the demethylation of juice pectins. The methanol content varied from 10 to 400 ppm in the test samples. I don't know which fruits are highest/lowest in pectin content, but apples are commonly considered the highest.
This is why all the old books on cider making refer to a condition called "apple palsey" - it's the massively painfull hangover from the high methanol content. In order to prevent this (I'm sure distilling the pectin turns it into methanol) distillers must fully clarify any fruit wine before cooking it. Rather than use clarifiers, put the wine into 2 or 4 liter plastic jugs (only filled half full) and freeze them solid, then thaw them out, this will result in perfectly clear (and chill- stabilized) wine ready for distilling. After the thawing is complete or maybe as much as a week after, the wine will be crystal clear.

Stephen Alexander reports that commercial spirits contain small levels of methanol. 'Food Chemistry' by Belitz&Groschlist an assay of about 50 different components of about 10 different distilled beverages. The US and Scotch whiskies had methanol levels around 0.2 to 0.3 %. Kevin Brown has scanned in some MeOH chromatograms from a column application guide published by Supelco of Bellefonte, PA. (a vendor for chromatography supplies). Check out for details.
See also "Increasing Direct Marketing for Fruit Farmers by Connecting Producer to Producer through Research and Development of a Value-Added Product" at for quite a detailed report into the compostion & quantities of impurities present etc in fruit brandies, and the factors affecting their production.
The Food and Drug Administration (FDA) advised ATF that 0.1 percent of methanol by volume in wine was a safe level. Any wine containing methanol in excess of this amount is deemed adulterated pursuant to the Federal Food, Drug and Cosmetic Act, 21 U.S.C. 34l(a)(2)(C) and 348.
From - it reckons that a molasses wash won't have any methanol present !

"....Molasses spirit can also be rectified and then used to produce vodka. In some countries it is even preferred, since it contains no methyl alcohol at all. Crop-sourced spirit contains infinitesimal amounts of methyl alcohol which have no effect on health, but some people, victims of their own overconcern, insist on molasses spirit. I should add that the presence of these tiny amounts of methyl alcohol have no effect whatever on the aroma of even unflavoured vodka. It is simply undetectable. In neutral grain or potato spirit the methyl alcohol has practically disappeared....."

"DBall" asks .. If Methanol is poison and is removed at the beginning of distillation... Question: When/how is methanol removed from wine or beer?
Brad answers ...

It's not tricky at all. Methanol is a by-product of fermentation; more methanol is produced in fruit fermentation than in grains. Brewers do not remove the methanol in beer and wine because methanol is not especially toxic at low concentrations. You are looking at between 0.4%-1% methanol in wines and brandies and smaller amounts in beers. Distillers remove almost all the methanol in most cases. Ever notice how vodka produces clean hangovers and wines (particularly reds) give you very nasty hangovers? Methanol. That, and dehydration!
Methanol is an especially nasty type of alcohol because the body tries to break it down the same way it metabolizes, or breaks down, ethanol, the type of alcohol in beer, wine and other drinks. Metabolizing ethanol produces chemicals less toxic to the body than alcohol. Unfortunately, if the same chemical action is performed on methanol the result is formic acid, lactic acid and formaldehyde.
Formaldehyde attacks nerve cells, especially the optic nerve and can damage the liver and kidneys. Formic acid and lactic acid also attack the kidneys and liver. Most people who have drunk methanol die of severe and sudden kidney and liver failure.
Chronic methanol drinking will cause optical damage. The stories of moonshine causing blindness comes from U.S. prohibition times where some bootleggers used to cut moonshine with methylated spirits to increase profit.

Gregory writes:

It isn't the yeast that controls methanol, it's what you're fermenting. I believe yeast has very limited metabolic pathways around methanol. Quoting from -
"Basically it can be produced biologically in 2 ways; through the oxidation of methane by methane monooxygenase, or by the reduction of formaldehyde, by methanol dehydrogenase (and this reaction normally works in the reverse direction).
It's true that some methanol can be produced during fermentation, but this is not derived from the ethanol or by carbohydrate oxidation. It is produced in small amounts, either by non-enzymatic reactions or through the reduction of formaldehyde."
Methane isn't present in our washes, so the culprit is formaldehyde. I believe the pectins in fruit are methylated and can break down in the wash into formaldehyde. But so long as your wash has only pure fermentable carbohydrates, you can expect essentially zero methanol. There's a bit more in this discussion of methanol here:
Ethyl acetate, OTOH, is produced spontaneously whenever acetate is present with ethanol. There are several possible sources of acetate during fermentation. In general, acetate is formed by oxidation of ethanol. (In fact, acetate is the 'end-product' of our own metabolism of ethanol). In fermentation, oxidation of ethanol into acetate can happen as a result of desperate yeast metabolizing its own ethanol, or by contamination with other yeasts or bacteria.
See

Fusel Oil Composition

Thanks to Brad, heres a bit more detail on what has been found in the fusels, and can be present in your distilled product:
Quotes from the MERCK INDEX 10th Ed. 1983 (entry number given):

4195. Fusel Oil.

A by-product of carbohydrate fermentation to produce ethyl alc. The material varies widely in composition, depending on the fermentation raw material used, but contains chiefly isopentyl alcohol and 2-methyl-1-butanol as well as isobutyl alcohol(20%), n-propyl alcohol(3-5%), and small amounts of other alcohols, esters and aldehydes. Described as an oily liq with a disagreeable odor; 60% boils at 122-138°. Amyl alcohol (commercial) obtained by chemical treatment and refining of fusel oil contains about 85% isopentyl alcohol and 15% 2-methyl-1-butanol. Ref: Industrial Chemicals, W.L. Faith et al.

5816. Methanol.

Methyl alcohol; carbinol; wood spirit; wood alcohol. Flammable, poisonous, mobile liq. Slight alcoholic odor when pure; crude material may have a repulsive, pungent odor. Burns with a non-luminous, bluish flame.bp 64.7°. mp -97.8°. Caution: Poisoning may occur from ingestion, inhalation or percutaneous absorption. Acute Effects: Headache, fatigue, nausea, visual impairment or complete blindness (may be permanent), acidosis, convulsions, mydriasis, circulatory collapse, respiratory failure, death. Death from ingestion of less than 30ml has been reported. Usual fatal dose 100-250ml. Chronic: Visual impairment, cf.Patty's Industrial Hygiene and Toxicology vol. 2C, G.D.Clayton et al. pp 4528-4541.
The alcohols of interest in the same MERCK: (just the boiling points at atmospheric pressure, some basic characteristics and all the alternative names for each alcohol)

212. Alcohol, Anhydrous. Ethanol

; ethyl alcohol. Clear, colorless, very mobile, flammable liquid; pleasant odor; burning taste.Absorbs water rapidly from air.bp 78.5°. mp -114.1°. Solidif below -130°.

4978. Isobutyl Alcohol.

2-methyl-1-propanol; isopropylcarbinol; 1-hydroxymethylpropane; fermentation butyl alcohol.Colorless, refractive liq; flammable; odor like that of amyl alcohol, but weaker.bp 108°. mp -108°.

5042. Isopentyl Alcohol.

3-methyl-1-butanol; isoamyl alcohol; isobutyl carbinol; primary isoamyl alcohol; fermentation amyl alcohol.Liquid; characteristic, disagreeable odor; pungent, repulsive taste.Vapors are poisonous! bp 132.0°. mp -117.2°. Caution: May be moderately irritating to mucous membranes. High concns may cause CNS depression, narcosis; lower concns, headache, dizziness.

5906. 2-Methyl-1-butanol.

Active amyl alcohol; dl-sec-butyl carbinol.One of the major components of fusel oil.Liquid, bp 128°.

5907.3-Methyl-2-butanol.

dl-sec-Isoamyl alcohol; sec-isopentyl alcohol; isopropyl ethyl carbinol. Liquid, bp 113-114°.Fusel oil component.

211.Alcohol, 95%.

Binary azeotrope having a distillate composition of 95.57% ethyl alcohol (by wt) and bp 78.15°C.Also specified as containing 94.9% by vol or 92.3% by wt of ethyl alcohol at 15.56°C. See U.S.P. XVIII, 20, 1067(1970). d 0.816 at 15.56°C (60°F).

6985. 1-Pentanol.

Pentyl alcohol; n-amyl alcohol; n-butyl carbinol.Liquid, mild characteristic odor.bp 137.5°C. mp -79°C. Slightly soluble in water (2.7g/100ml at 22°C); misc with alcohol, ether. LD50 orally in rats: 3030mg/Kg, P.M.Jenner et al., Food Cosmet. Toxicol.2, 327 (1964). Toxicity: Irritating to eyes, respiratory passages. Narcotic: E.Browning, Toxicity and Metabolism of Industrial Solvents (Elsevier, New York, 1965)pp 356-367.

6986. 2-Pentanol.

dl-sec-Amyl alcohol; methyl propyl carbinol. Liquid, characteristic odor.bp 119.3°C. Slightly soluble in water (16.6g/100ml at 20°C).Miscible with alcohol, ether. Caution: see 1-Pentanol.

6987. 3-Pentanol.

Diethyl carbinol.Liquid, characteristic odor.bp 115.6°C. Slightly soluble in water (5.5g/100g at 30°C); sol in alcohol, ether. LD50 orally in rats: 1870mg/Kg, Smyth et al., Arch. Ind. Hyg. Occup.Med. 10, 61 (1954). Caution: see 1-Pentanol.
Brad also commented :
As you can probably see from these brief descriptions, methanol appears to be one of the most toxic of all. In fact the other alcohols by and large appear to have much the same effct as ethanol when consumed (with much greater activity/toxicity), except methanol which has some toxic metabolite (formaldehyde) which is somehow toxic to the optical nerves of the eye. Ethanol administration is actually used to slow down the metabolism of methanol when it's accidentally consumed!! Note the Merck note about Chronic effect (long-term use) of methanol being visual impairment; does this occur to heavy drinkers?!?