Extraction: The process by which pigment, tannins and flavor and aromatic compounds contained in grape skins are dissolved into wine. Extraction is most commonly achieved through maceration (soaking the skins of the crushed grapes in the wine after fermentation), during which alcohol helps dissolve flavor, aroma and especially tannin molecules—as with a steeping tea bag, the longer and warmer the maceration, the greater the degree of extraction. During fermentation, punching down the cap (floating layer of skins, seeds and stems) and pumping liquid from the bottom of the tank over the cap (pump-over) are other methods of extraction. For reds made in lighter-bodied styles such as Pinot Noir, a pre-fermentation cold soak of the skins in the grape juice can extract water-soluble flavor and pigment molecules while limiting the amount of more alcohol-soluble tannins released into the wine.
Extract: Richness, depth and concentration of fruit flavors in a wine. Usually a positive quality, extract adds to wine’s body, yet highly extracted wine can also be very tannic. To calculate extract levels, some winemakers measure the dry residue remaining after the wine is boiled off.
Maceration: This process, used primarily in making red wine, involves steeping grape skins and solids in wine after fermentation, when alcohol acts as a solvent to extract color, tannins and aroma from the skins (aided by heat, the amount of skin contact and time). Cold maceration (steeping when the must is not heated), takes place before fermentation.
Pump-Over: Also known as remontage, the process of pumping red wine up from the bottom of the tank and splashing it over the top of the fermenting must; the purpose is to submerge the skins so that carbon dioxide is pushed to the surface of the must and released.
Punch-Down: Also known as pigéage, the process of breaking up the thick layer of skins, stems and seeds that forms at the surface of fermenting red wine and submerging it during fermentation to extract color, tannins, flavor and aromas from the grape solids.
Cap : The thick layer of skins, stems and seeds that forms at the surface of fermenting red wine. Cap management, or breaking up the cap to increase contact between the skins and the liquid, is important since red wines extract color and flavor from the skins.
Tannins: The mouth-puckering polyphenols, most prominent in red wines, that are derived primarily from grape skins, seeds and stems, but also from oak barrels. Tannins are an important component of a wine's structure and texture, and act as a natural preservative that help wine age and develop.
Polyphenol: Chemical compounds found in plant life. In grapes, polyphenols are responsible for skin pigment, tannins and flavors—all of which fall under the category of flavonoids—as well as resveratrol, the compound associated with many of wine's health benefits, and which falls under the much smaller polyphenol category of non-flavonoids. Pertaining to wine, grape skins, seeds and stems contain the highest concentrations of polyphenols.