Dear Winemaking Experts,
I enjoyed reading your homemade wine instructions on making wine from grapes. I hope you can answer my question. Why is it important to ferment the must with the grape skins prior to pressing? Your article says that white wine grapes can be pressed right away, whereas, red wine grapes is fermented prior to pressing. Please explain because I want to lean how to make white wine later this year.
This is a great question, and an area of wine making that causes a lot of confusion for many beginning winemakers.
The first thing I want to say is that if you are making wine from concentrated juices, the skins have nothing to do with your wine making at all. The concentrate producers have taken care of everything for you when it comes to handling the grape skin or pulp. So just relax.
If you take the reddest grapes you can find and run them through a grape crusher. Then press the grapes. You will not have a red juice. What you will have a pink or blush juice. If you ferment that juice you will have a pink or blush wine, not a red wine. There is nothing in the fermentation process that will make it turn any redder.
The color in a red wine comes from the grape skin not the juice. This is the reason that the skins are left in the must during the fermentation, so that the color can be extracted into the juice. There are also body and aroma elements that are extracted as well making the wine bigger.
With white wines it now starts to become obvious why the grapes are pressed right away. Contact with the skin has very little value wine making a white wine. Some wineries do live the pulp and skins in with the juice for a very short period of time to add depth to the white wine, but it is usually a matter of hours not days.
I hope this answers you question sufficiently. If not, please feel free to email us back.
Happy Wine Making,
Customer Service at E. C. Kraus