The best tasting vinegar is made from sweetened (1 lb. brown sugar per gal) apple juice that has first been fermented into hard cider, but other foods with a sugar, starch (convert to sugar as above), or alcohol content can be used. The skimmings from boiling syrup make good vinegar. A little brown (unpasteurized) vinegar can be added as a starter. Instead, the pioneers added wild bacteria by pouring the fresh juice or syrup through a mat of twigs and leaves from beech or maple trees. The environment for vinegar bacteria can be improved with a warm temperature (100 deg F is ideal) and an aquarium aerator (or pour the liquid from one container to another daily). The jelly-like mass that forms on top of a crock of vinegar is clumped bacteria and is called mother; pieces can be used as starter. A gallon jug of homemade vinegar need never run out; when it is half full, add 1-2 cups of sugar or syrup and refill with water. Caution: vinegar must be stored in glass or plastic; it is corrosive to copper, zinc, and iron.