Racking: The practice of moving wine from one container to another for aeration or clarification, leaving sediment behind.
Cold Stabilization: A clarification technique that can prevent the formation of crystals in wine bottles. Prior to bottling, the wine's temperature is lowered to approximately 30° F for two weeks, causing the tartrates and other solids to precipitate out of solution. The wine is then easily racked off (separated from) the solids.
Lees: Sediment—dead yeast cells, grapeseeds, stems, pulp and tartrates (harmless tartaric acid crystals)—remaining in a barrel or tank during and after fermentation. Immediately following fermentation, wine should be racked off of the gross lees, the large particulate matter such as seeds, skins and stems, which are rich in spoilage organisms. The wine may be aged for an extended period on the fine lees, however, in what's called "sur lie" aging. Fine lees, the dead yeast cells leftover from fermentation, can enhance an aging wine with added richness, flavor and aroma complexity, and can also bind with excess tannins.
Sur Lie: Wines aged sur lie (French for "on the lees") are kept in contact with the dead yeast cells and are not racked or otherwise filtered. This is mainly done for whites, to enrich them. (It is a normal part of fermenting red wine, and so is not noted.) The concept originated in Burgundy, with Chardonnay, but is now popular around the world with numerous white grape varieties. Sur lie aging can be overdone, leading to an off-putting leesy flavor.
Riddling: In making sparkling wine, the process of moving the sediment remaining in the bottle from the second fermentation to rest in the neck of the bottle for easy removal. The process of riddling is part of the méthode traditionelle and was developed by Madame Clicquot (Veuve Clicquot) in the early 1800s to remove the cloudy lees from the bottles. The bottles are loaded in a horizontal position onto wooden racks called pupitres. At this point, the sediment rests on the side of the bottle. As the bottles are riddled, or given a sharp quarter-turn daily and gradually tilted upside-down, the sediment works its way to the bottle neck. Today, most producers use efficient mechanical riddlers. Also known as Remuage.
Kosher Wine: Wine made according to Jewish dietary laws (the kashrut) and certified by rabbinical authorities. Only observant orthodox Jews can handle kosher wine during the winemaking process, including tasks such as racking and drawing samples from barrels. Common fining agents forbidden in the production of kosher wine include casein and isinglass, though the use of egg whites is permitted.
Winemaking: Largely synonymous with "Vinification," winemaking is the process by which harvested grapes are crushed, fermented (and otherwise manipulated through yeast inoculations, temperature control, punch-downs, pump-overs, racking, oak-chip additions, filtering, etc.), aged in barrel, steel tank or other vessel, and finally bottled.
Appassimento: Italian term for drying harvested grapes, traditionally on bamboo racks or straw mats, for a few weeks up to several months to concentrate the sugars and flavors. This process is used in making Amarone, Recioto and Sforzato.
Oxidative: Refers to winemaking practices that deliberately expose the wine to oxygen, such as the use of open-top fermentors and racking. Traditional winemaking exposes the wine to some air, but does not result in oxidized notes. An aggressively oxidative approach can result in nutty notes, as seen in wines such as Sherry or vin jaunes from the Jura.