Acetic: Acetic acid is the acid that gives vinegar its characteristic taste. Small amounts of acetic acid, about 0.5 grams/liter, are normal in wine; amounts over 1.0 gram/liter give wine a vinegar-like character.

Acidity: The natural crispness of a wine. Grapes have two primary acids: tartic and malic. Citric, lactic and succinic acids are usually also present in small amounts in grapes.

Aging Sur Lie: Translated "aging on the lees," and often referred to as "yeast contact." Wine is aged in the barrel with the yeast retained, rather than being clarified before aging. Aging on the lees increases the complexity and creaminess of the wine.

Alluvial: Soil that contains clay, silt, sand or gravel deposited by running water is said to be alluvial. Grapes grown in mostly sandy and stony alluvial soil produce wines with more concentrated fruit flavors.

Barrel Aging: The process of holding wine in oak containers to allow flavor and aromatic compounds to mature and change beneficially.

Barrel Character: The flavor and aromatic compounds an oak barrel contributes to the wine. Barrel character varies by the origin or forest of the wood, coopering techniques including toasting and length of oak aging, and the age of the barrel.

Barrel Fermentation: The conversion of grape juice into white wine by yeast in a 60-gallon French oak barrel. Barrel fermentation gives Chardonnay and Sauvignon Blanc more complexity and integrated oak flavor.

Bloom: Flowering of the grapevines. Bloom is also a waxy substance found on the skins of grapes.

Botrytis: Botrytis Bunch Rot is a vine disease caused by fungus that attacks ripe, white wine grapes. The benevolent form is known as “noble rot” which is responsible for the world’s finest sweet wines.

Brix: The measurement of soluble solids in grapes at harvest, taken with a refractometer and expressed in degrees. In unfermented grapes, degrees of Brix are approximately the same as percent of sugar. After fermentation, the alcohol concentration is roughly half the sugar concentration of the juice. Thus, grapes harvested at 22.5 degrees Brix will produce a wine with an alcohol content between 12.5 to 13.5%.

Bud: A small protuberance on a stem or branch, often enclosed in protective scales and containing an undeveloped shoot, leaves or flowers.

Bud Break: When the first shoots emerge on a vine after winter dormancy.

Bunch Rot: See Botrytis.