How is alcohol made?
Ethanol is commercially produced using a process called fermentation. Many other alcohols can be made this way, but are more likely to be produced by synthetic routes - from natural gas, oil or coal.
Fermentation is the process in which yeast breaks down sugar into alcohol and carbon dioxide. Yeast are tiny single-celled fungi that contain special enzymes responsible for this reaction.
The word equation for this process is:
Glucose + yeast alcohol + carbon dioxide
Carbon dioxide gas bubbles out of the fermenting solution into the air leaving a mixture of ethanol and water. It's important that no air is present or the yeast will produce ethanoic acid - the chemical found in vinegar.
Beer and lagers:
Barley, hops, water and live yeast produce beers and lagers. The sugar in the mix comes from the spouting barley. Bitter, stout and ale use top-fermenting yeast, while lager uses a variety that sinks to the bottom.
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Wine:
In wine making the sugars come from the flesh of the crushed grapes. The type of wine produced depends on the type of grape used in the process.
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Other Products:
Fermentation is also used in bread making; the yeast is mixed with the dough and kept warm. The carbon dioxide produced by fermentation makes the bread dough rise and the alcohol evaporates.
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Reference: alcohol and you