White wines are typically pressed as whole clusters and then just the juice ferments and the skins and stems are discarded. There are several options to destem white grapes and leave the juice in contact with the skins for a period of time, which can add palate weight, and flavor to the wine. Then there is the rare situation where you destem the grapes and ferment the wine in contact with the skins all the way through fermentation. This will likely yield a wine that is a bit too bitter but this wine can be successfully used to enhance both red and white wines when blended in. Here's a look at the process.