Mary writes:
When winemakers make wine one technique they use is to macerate the grapes.
When they macerate before fermentation, it’s a cold maceration. Cold maceration extracts color and aromas.
During fermentation, a winemaker will punch down the cap that sits on top of the fermenter. This warm maceration technique, in the presence of alcohol, extracts more aromas, color and tannins from the skins.
This is like dunking a tea bag in hot water — the more you dunk, the more extracted from the tea bag.