protective juice handling, grape and must processing techniques with the aim of minimizing exposure to oxygen and therefore the risk of oxidation. This is regarded as especially important for white wines since, once grapes are crushed and juice liberated from the berry, the phenolics react rapidly with oxygen to produce amber to dark-brown polymers (see polymerization). Some ordinary wines are made encouraging this oxidation, the brown pigments being removed subsequently by fining. Most better-quality white wines result from minimal oxygen exposure, saving the phenolics for later contribution to aroma and body. (Some ambitious winemakers experimented with deliberate prefermentation oxidation of the must in the early 1980s but this is uncommon today.) The introduction of tank presses has aided protective juice handling during the lengthy pressing operation enormously. See also nitrogen. Grapes for red wines are far less vulnerable to damage from oxygen since they contain much greater concentrations of tannins and pigments.
