The Winemaking Process

Sugar in the grape juice, through the activity of yeast, is fermented into alcohol in the wine. The equation for this chemical change is: C6H12 O6 g2 CH 3 CH 2OH + 2 CO2h or literally one molecule of glucose (sugar) is fermented to yield 2 molecules of ethanol (alcohol) and 2 molecules of carbon dioxide gas (bubbles). The alcoholic fermentation also produces heat.

It is necessary to know the level of sugar in the juice you begin with. Sugar level is measured with either a hydrometer or a refractometer. By multiplying the sugar level (in °Brix) by a factor of 0.55, you can estimate the future alcohol level. You want a final alcohol level between 10 and 14% for table wines so you need to start out with a juice that has a sugar level from 20 to 24 °Brix.

The first major step in the winemaking process is to extract the juice from the grapes.  This step can be skipped if you begin with purchased fresh juice or juice from concentrate.  The second major step is to ferment the juice and clarify and stabilize the wine.  The third major step in winemaking is to bottle the wine and store it properly.  The last step is to evaluate and enjoy your wine.