A 1-gallon container should be filled with sugar, juice concentrate, and yeast. Add cold water to the jug until it is fully filled.
After thoroughly cleaning it, place a big balloon over the jug's opening. With a rubber band, hold the balloon in place.
Put the jar in a cool, dark location. You'll see the balloon start to grow after a day. Gases will be released as sugar converts to alcohol and fill the balloon. The wine will be ready to drink once the balloon has deflated. It takes roughly six weeks all told.