Wine

In this chapter

• Aging wine — Slow change in wine after fermentation, driven by oxygen exposure, vessel, and ongoing reactions among phenolics, acids, and aroma compounds.
• Appellation of origin — A U.S. wine-label geography — country, state, county, or AVA — with grape percentages TTB sets, not a tasting score and not terroir.
• Barrel — An oak vessel that slowly admits oxygen and can add hydrolyzable tannin and toast flavors — a winemaking tool, not a synonym for quality.
• Brix — Dissolved solids in juice or wine expressed as grams of sucrose per 100 grams of solution at 68 °F — a density number, not a tasting of sweetness and not a harvest commandment.
• Carbonic maceration — Intact grape berries shifting to anaerobic, intracellular fermentation under carbon dioxide before yeast in the free juice finish the wine — not a punch-down of crushed must.
• Chaptalization — Adding sugar or same-fruit concentrate to low-sugar juice before or during fermentation so yeast can make more alcohol — U.S. wine law caps the juice at 25 degrees Brix.
• Clarification — Removing haze-forming protein, yeast solids, and other colloids from juice or wine so the liquid looks bright — a cellar finish, not extraction and not the crush.
• Extraction — Moving color, tannin, and aroma from grape skins and seeds into juice during maceration and fermentation — a contact-and-alcohol problem, not a virtue meter.
• Fortified wine — Kitchen name for grape wine whose alcohol is raised with added grape brandy or spirits — U.S. identity splits that world into dessert wine and aperitif wine, not a Port postcard.
• Lees — The sediment of dead yeast and grape solids after fermentation — a texture and flavor contact, or a sludge you rack away, depending on the wine.
• Malolactic fermentation — A bacterial conversion of sharper malic acid into milder lactic acid after (or alongside) alcoholic fermentation — a texture and aroma decision, not a second yeast ferment.
• Must — Crushed grape destined for wine — juice plus whatever skins, seeds, and pulp the winemaker keeps in contact — before alcoholic fermentation finishes.
• Pressing wine — Separating juice from grape skins, seeds, and stems — the mechanical end of extraction, distinct from pressing cheese curd.
• Residual sugar — Sugar left in wine after alcoholic fermentation stops or is stopped — sweet taste, not a second fermentation science page.
• Sparkling wine — Grape wine made fizzy by carbon dioxide from a closed fermentation — tank or bottle — as distinct from wine that was injected with gas.
• Sulfur dioxide — A wine additive and fermentation by-product used as an antioxidant and antimicrobial — a measured cellar practice rather than a tasting-note flavor.
• Tannin — Phenolic compounds, especially from grape skins and seeds, that bind saliva proteins and make wine feel dry and astringent.
• Tasting wine — A method for noticing appearance, aroma, acidity, tannin, alcohol, and finish in a glass without turning tasting into theater.
• Terroir — The idea that a place's climate, soil, and culture shape a food — useful as interpretation, not as a substitute for an appellation rule or a lab result.
• Vineyard — A planted place where wine grapes grow — climate, slope, and vine, later named on a label only when appellation rules are met.
• Vintage — The harvest year of the grapes in a wine — a weather story first, a label rule second, not a guarantee of quality.
• Wine fermentation — Yeast converting grape sugar in must into ethanol and carbon dioxide — the alcoholic ferment that makes wine, distinct from malolactic bacteria and from sourdough.
• Wine filtration — Passing wine or juice through a barrier so particles stay behind — from rough solids to protein — with the barrier selected for the material and desired result.