How to Avoid Methanol When Distilling Alcohol

Making your own spirits at home is not only interesting, but also a great learning experience. However, preparing any alcoholic beverage by yourself calls for the right care and precision.

How is Methanol Produced?

Also known as methyl alcohol or wood spirit, methanol is the simplest (shortest chain) of alcohols which is one-part carbon, one-part oxygen and four parts hydrogen.

Methanol is commonly produced commercially from coal, natural gas, and other renewable sources such as recycled carbon dioxide, biomass, and municipal waste. Initially, it was produced by performing a destructive distillation of wood, but nowadays it’s produced from synthesis gas by combining hydrogen and carbon monoxide with the help of a catalyst.

Apart from that, methanol is also produced in small amounts during the process of alcohol distillation. It is produced at the initial stages of the process and is tossed out by the distillers. This biodegradable form of alcohol is an organic water-soluble chemical.

DEGONG copper distillery equipment

How to Minimize Methanol in Fermentation?

When making alcohol at home, it’s the fermentation stage that produces methanol.

The amount produced will vary with different conditions, including the temperature, the type of yeast and other bacterial in the solution, the type of food you provide to them, the minerals, and more.

Normal fermentation of starch-derived sugars from corn, wheat, and barley will only contain very small amounts of compounds that will turn into methanol during fermentation.

A couple of general rules to minimize methanol when distilling are:

• Be more wary of methanol when distilling fruits, as opposed to sugar washes, grain washes, or whiskeys.

• Brandy made from distilled fermented grapes will have a lower methanol content than schnapps (fruit brandy) made from fermented apples, or citrus.

• Remove pectin from the food sources you are using, or simply go for items that don’t contain pectin. This prevents microorganisms from producing methanol.

• Use high-quality, reliable yeast.

• Make sure to control the temperature and don’t let it go too high during fermentation.

• Sterilize everything before fermentation to kill harmful bacteria.

Can you Test for Methanol in Alcohol?

Yes! You can test for the presence of methanol in an alcoholic beverage by performing some quick tests.

The Smell Test

Smelling the beverage is the easiest methanol test yet one that takes a lot of practice to hone your senses. If you sense an unpleasant chemical odor from the solution, the drink is not safe for consumption.

Methanol has a sharp, stinging scent that is quite potent and can be easily recognized as ‘the smell of alcohol’

Ethanol will smell much milder by contrast. It’s softer, less stingy, and almost has a ‘creamy’ aroma. Ethanol won’t smell as potent as methanol of the same concentration.

Compared to methanol, ethanol will smell very pleasant – but it’s very hard to tell if you’re not comparing the two side by side.

The Flame Test

Take a small sample of the alcohol solution and light it on fire – if you witness a yellow fire instead of a blue flame, the solution contains methanol.

Again, this test is good in theory, but in practice you’ll seldom be comparing two solutions that are entirely methanol or ethanol. They will be blended and of varying proportions.

Also, be very careful setting things on fire as distilling is a potentially explosive process. Keep any open flame well away from a running still.

The Chemical Test

A more effective test for methanol in alcohol is to apply sodium dichromate to a small sample of the solution.

All you need to do is mix 8 mL of a sodium dichromate with 4 mL of sulfuric acid, further swirling the mix and adding 10 drops of the same to a small container or a test tube containing the alcohol to be tested.

Gently swirl test tube, followed by using your hand to fan the air from the opening of the test tube towards your nose while you hold the tube 10-12 inches from your nose. Notice the smell – if it’s unpleasant and pungent, then the alcohol contains methanol. However, if it seems fruity, the beverage contains only ethanol and is safe for consumption.