Chemistry onlyUnfortunately most alcohols are toxic and are definitely not suitable as drinks. The one alcohol which is less harmful is ethanol, although it still causes many people to do very silly things when taken in excess! Ethanol has been made for thousands of years as an alcoholic drink. Traditionally beer was made in large copper tanks or vats as shown in the image.
Making alcohol using yeast is very simple. All you need is a source of sugar, it could be any fruit e.g. apples, pears,
strawberries, blackberries, grapes. The fruit is squashed, added to lukewarm water and placed in a bucket with a lid
or air lock somewhere hot, like an airing cupboard or beside a radiator. Once the yeast is added fermentation will begin.
After about 2 weeks filter the mixture to remove the yeast and any other solids present. That is it.... Easy, you have made ethanol!
Yeast is a fungus, a living organism, and it will produces enzymes that turn glucose into ethanol. This is a form of anaerobic respiration which work best around 370C. If the fermenting solution gets to hot then the yeast will be killed and fermentation will stop. If the solution is kept too cold then obviously fermentation will be very slow. Air needs to be excluded since bacteria and oxygen present in the air will oxidise the ethanol into ethanoic acid (vinegar). One of the uses for alcohol is as an agent to kill bacteria and fungi. Once the concentration of alcohol in the fermenting container reaches around 15% alcohol fermentation stops- this is because the alcohol has killed the yeast. For alcoholic spirits such as whisky or vodka which may contain up to 40% alcohol, the alcoholic solution from fermentation needs to be distilled
Alcohol (ethanol) used in alcholic drinks such as beer, wine and spirits is made by fermentation. However alcohol can also be made a method called direct hydration. Using this method produces alcohol very quickly and being the only substance made there is no waste and no costs needed in separating out unwanted substance.
Alcohol used for industrail purposes e.g. solvents and in sanitisers will more than likely be made by the direct hydration method rather than fermentation. Here steam is added across the C=C in an alkene as shown below. A catalyst and some heat are both needed to get this reaction to occur smoothly.
Equations for this reaction are: