Making wine from grapes requires you to first crush the grapes into "must," then add yeast and allow the wine to ferment for several days. During this process, you should also monitor the sugar levels and acidity of the must to ensure that the yeast ferments the grapes into wine.
To make wine, begin with 18 pounds of white or red grapes. Sort through them, removing stems, leaves and any moldy clusters. Place them in a nylon straining bag, and then place the bag in the bottom of a food-grade pail. Crush the grapes into must, either with your hands or a sanitized tool. Add a crushed campden tablet to the nylon bag, then cover the pail with a cheesecloth, and wait at least one hour. Measure the temperature, acidity, and specific gravity of the must, and adjust if necessary.
Mix yeast and water. Once this mixture is bubbling, add it to the nylon straining bag, agitate the bag, and cover with cheesecloth. Fermentation should begin within 24 hours. When the wine has reached your desired dryness as measured by its specific gravity, remove the straining bag, and give the wine 24 hours to settle before siphoning into another sanitized container, topping off with a similar wine, and allowing it to ferment another 10 days.
After 10 days, siphon the wine into another sanitized container, and allow it to sit for three months before bottling.