Wine making, whether commercially or for personal consumption, involves growing, harvesting, destemming and crushing grapes for their juice. The juice is then allowed to ferment before being bottled and sold. (According to Wine for Beginners, fermentation is the process of converting sugar into alcohol. When making wine either a cultured yeast or a "wild" yeast is added to the grape juice, the yeast interacts with the sugar converting juice into alcohol.) Because the skin and seeds of grapes contain tannin, which gives wine a dry, astringent taste, white wine is made from grapes that have been deseeded and have the skin removed. According to "The Complete Idiot's Guide to Wine Basics" by Tara Q. Thomas, the skin of red or purple grapes is considered essential in accentuating the color and taste of red wine. Whether making red or white wine, you will need to use fresh or frozen grapes.
Buy or grow grapes in bulk. It can take hundreds of grapes to make one bottle of wine. Grapes can be purchased at your local grocery store or ordered online. To grow grapes you need to purchase vines (from either an online distributor, a catalog or your local nursery) and plant them in an area that receives a lot of sunlight. Make sure the ground is soft enough that they can put down deep roots and build a trellis or other support structure to hold the weight of the grapes.
Destem, crush and freeze the pulpy mixture of red or purple grapes to make red wine. Remember the skin is essential to giving red wine its color and flavor.
Run white grapes through a press to extract the juice for freezing when making white wine. A press contains a compression plate that is either manually or hydraulically driven which crushes the grapes for their juice. Grapes waiting to be crushed are usually contained in a sack cloth (or cheese cloth) lined barrel or basket.
You can also freeze whole grapes by thoroughly washing them, removing them from the vine, allowing them to dry, then storing them in thick freezer bags.