Reference
Glossary
Wine and culinary terminology, defined for enthusiasts and certification candidates alike.
A
- Alluvial FanTerroir
- A fan-shaped deposit of sediment where a stream emerges from a mountain onto a valley floor. Napa Valley's alluvial fans are central to its terroir, providing well-drained, gravelly soils.
- AVARegulation
- American Viticultural Area — a federally designated grape-growing region distinguished by geographic features (climate, soil, elevation) that give it distinguishing character. Established and administered by the TTB.
B
- BudbreakViticulture
- The spring stage when vines begin new growth, with buds swelling and bursting into shoots. It marks the start of the annual vine cycle and is vulnerable to frost.
D
- DiurnalTerroir
- Relating to a 24-hour cycle; in viticulture, 'diurnal shift' refers to the day–night temperature swing that affects ripening and acid retention.
- Diurnal ShiftTerroir
- The difference between daytime high and nighttime low temperatures. Large diurnal shifts, common in Washington and Oregon, preserve acidity by slowing nighttime respiration.
M
- Malolactic FermentationWinemaking
- A secondary fermentation converting tart malic acid to softer lactic acid, common in red wines and oaked Chardonnay, producing a creamy, buttery texture.
- Mission GrapeViticulture
- The first European grape planted in California by Spanish friars; a Criolla variety (Listán Prieto). It dominated early California viticulture until replaced by European vinifera.
N
- Noble RotViticulture
- Botrytis cinerea, a beneficial fungus that desiccates grapes, concentrating sugars and flavors. It produces some of the world's finest sweet wines (e.g., Sauternes).
O
- Old VineViticulture
- An unregulated term for vines of significant age, often 50+ years. Old vines typically yield less and produce more concentrated fruit; Dry Creek Zinfandel is famously 'old vine'.
P
- PhylloxeraViticulture
- A root-feeding aphid (Daktulosphaira vitifoliae) native to North America that devastated European and California vineyards in the 19th century. Control requires grafting vinifera onto resistant American rootstock.
- PunchdownWinemaking
- A red-wine cap-management technique of submerging the floating grape-skin cap into the fermenting juice to extract color, tannin, and flavor.
R
- Rack and ReturnWinemaking
- A technique of draining fermenting red wine off its skins and pumping it back over the cap to manage extraction and oxygenation.
T
- TanninTasting
- Astringent, mouth-drying compounds from grape skins, seeds, and oak that structure red wine and soften with age. High in Cabernet Sauvignon, low in Pinot Noir.
- TerroirTerroir
- The total natural environment of a vineyard — soil, climate, topography, and aspect — that gives wine a sense of place. The AVA system is the U.S. legal expression of terroir.
V
- VeraisonViticulture
- The onset of grape ripening, when berries soften and change color (red varieties turn from green to red/purple). It signals the transition from growth to sugar accumulation.
- VigorViticulture
- The growth rate and canopy density of a vine. Low-vigor sites (thin, well-drained soils) typically produce more concentrated, higher-quality fruit than high-vigor sites.
- ViniferaViticulture
- Vitis vinifera, the European grape species that produces nearly all the world's fine wine. Unlike American species, it is susceptible to phylloxera and requires grafted rootstock in most regions.