The same is true of the production of my hosts. The wine must be made of the juice of ripe grapes. Whatever is in involved in the making of wine is to be followed. One may use either the fresh grapes or the dried grapes, called raisins. One should use white or green-colored grapes, for that gives a yellow wine.
Blue grapes give a blue wine, which is perfectly all right.
The alcoholic content of the wine should be between 12 and 17 percent. There are testers on the market to test for the alcohol content of wine. When the alcohol content is low the wine spoils very easily. When the alcohol content is in the high range the wine keeps much longer. Over the years I have carried by car and by air all the wine that I use in Mass, so these are words again of experience.