Alcohol is produced by yeast under anaerobic (little or no oxygen) conditions, whereas vinegar is produced by bacteria under aerobic conditions. Both bacteria and yeast spores are present in the air, and conditions favorable to one organism or the other determine the product. However, a covered crock of cider will usually change first to wine and then to vinegar. Fermentation ceases when sugars are completely changed to alcohol or when the yeast is inhibited by the alcohol content. The yeast that causes a cloudy appearance when fermentation slows has the highest alcohol resistance; if some of this liquid is saved from each batch, the alcohol content of future batches gradually increases. About 2 Bu. of grapes make 5 gal of wine. The strongest wine (12% alcohol) requires the equivalent of 3 lb. sugar per gallon of juice. Sugar can be added, or weaker fruit juices can be concentrated by boiling before fermen-tation begins. All fruit has a sugar content and can be used to make wine, but grains have a higher fermentable content, and sweet potatoes have twice as much as grapes and apples. Next highest are Jerusalem artichokes and potatoes.
The pioneers made wine and beer from molasses, honey, maple syrup, bran, malted corn, corn stalks, persimmons (and all other fruits), Jerusalem artichokes, potatoes, pumpkin, and squash.