Cheese is made by coagulating milk to give curds which are then separated from the liquid, whey, after which they can be processed and matured to produce a wide variety of cheeses. Milk is coagulated by the addition of rennet. The active ingredient of rennet is the enzyme, chymosin (also known as rennin). The usual source of rennet is the stomach of slaughtered newly-born calves. Vegetarian cheeses are manufactured using rennet from either fungal or bacterial sources. Advances in genetic engineering processes means they may now also be made using chymosin produced by genetically altered micro-organisms.
These contain the words “suitable for vegetarians” on the packing. Vegetarian cheeses are made with rennets of non-animal origin. In the past, fig leaves, melon, wild thistle and safflower have all supplied plant rennets for cheese making. However, most widely available vegetarian cheeses are made using rennet produced by fermentation of the fungus Mucor miehei. Vegetarian cheese may also be made using a rennet from the bacteria Bacillus subtilis or Bacillus prodigiosum.
Spirit vinegar is distilled before the acetification process has finished and contains a small amount of alcohol which changes the flavor dimension of the vinegar.
When bacteria ferment they create one of two possibilities, ethanol CH3CH2OH, or acetic acid, CH3COOH. Acetic acid is a more oxidized form of ethanol. Ethanol is what you want if you're making wine, beer, liquor, etc. Acetic acid is what gives all vinegars their distinct taste, and the simplest of all vinegars would be a ~3% solution of acetic acid. Most vinegars contain additional flavor components. Any acetic acid in an alcoholic drink however would make it bad, since it has a very strong flavor.
In spirit vinegar, the fermentation process is stopped before the bacteria have completely converted all the ethanol (which is always found in very small amounts anyway) into acetic acid. Whereas even a small amount of acetic acid in alcoholic beverages would completely ruin the flavor, the small amount of alcohol left over in spirit vinegar enhances the flavor in some people's opinions.
If you are asking this question on a practical "I want to get drunk" level. The answer is that drinking spirit vinegar would be just about the stupidest way to get drunk. The percentage of alcohol is miniscule, and you would probably have to drink gallons of vinegar to get drunk from it.
Heinz ketchup and beans contain spirit vinegar!
