You remember your child asking, "Mommy, does chocolate milk come from brown cows?" Unless you had a particularly perverse sense of humor ("Now, Jesse, that is udder nonsense!") you gently set your child straight and provided him or her with one more piece of life information.
So when people ask me whether white wine comes from white grapes and red wine from red ones, I have to smile my brown cow smile .
Here is the straight information, from winemaker to you. The word "sometimes" is used because the winemaker, who is a sort of chef d'grapes has a lot of options available in his kitchen/winery and we all make it somewhat differently.
When white grapes are crushed, they are pressed immediately or sometimes after a day or so of grapeskin contact. The resulting juice is fermented into wine. When it is finished it is white wine, or more accurately, a shade of light straw or very faint green wine. .
Red grapes are crushed and the juice is left on the skins to ferment for a week and sometimes much longer. It is during this skin contact that the red color leeches out of the skins and into the liquid as it is becoming red wine. When the fermentation is complete, then the wine is pressed from the skins.
Now here's what's neat: If you take red grapes, crush them and immediately, remove the juice from the skins and ferment it separately, you will end up with a wine that is "white". Or close to it, depending on the grapes. Champagne is sometimes made partially from pinot noir, a red grape.
At one point, this process was the true source of what we call "blush wines" because you cannot get the juice away from ripe red grapeskins fast enough to avoid some pink color. And a very popular new wine category was born.
