A great deal of work can go into making the perfect bottle of wine, but if you are more interested in just making a quick and easy bottle of wine you can do so with common household items. While professional winemakers wouldn't normally use baker's yeast to make their wine, it is not very different from the yeast that is traditionally used.
Wash and sterilize both gallon jugs. Pour your container of grape juice into the first gallon container.
Put the cup of sugar into the gallon container by placing the funnel in the container's opening and pouring the sugar inside. Recap the container and shake vigorously.
Hydrate 2 packets of baker's yeast in warm sterile water (95-105°F) in a sterilized cup. Add a teaspoon of sugar to the cup. If the yeast is not producing an inch of foam within half an hour, you will need to start over and try again. If the yeast is producing about an inch of foam after half an hour, pour the mixture into the gallon container.
Poke three holes in a balloon. Place the balloon over the top of the open gallon container. Shove the top of the balloon into the top of the container so that it is inside out. Wrap the rubber band around the mouth of the container to secure it in place. The balloon will allow CO2 to escape the container while letting nothing in. As CO2 leaves the container, the balloon will inflate slightly and deflate when the holes open back up.
Wait for approximately 24 hours. The jug should be showing visible signs of fermentation by this time and the balloon should be either partially or completely out of the gallon container. Leave the container covered with the balloon in a cool, dry and dark place for 30 days and the fermentation process will be complete. When the wine starts producing less CO2, you will know that the wine is nearing the end of the fermentation process.
Siphon the wine from the gallon jug used to contain the yeast, sugar and juice into the empty container. Your wine is ready to drink. To improve flavor, allow the wine to sit an additional two weeks.