Chardonnay

Chardonnay is the most widely planted quality white grape in the world and the most malleable. It has very little inherent aromatic character — green apple, lemon, a little white flower — and almost everything people associate with it comes from where it is grown and what is done to it in the cellar.

That neutrality is its great strength. In Chablis, on Kimmeridgian limestone full of fossilised oyster shells, it makes a lean, high-acid, flinty wine usually made without new oak. Fifty kilometres south in the Côte de Beaune, in Meursault and Puligny-Montrachet, barrel fermentation and lees stirring produce something rich, hazelnutty and profound. In Champagne it is the sole grape of Blanc de Blancs, prized for the tension it brings. In warm parts of California and Australia in the 1980s and 1990s it was fermented ripe in heavily toasted new oak and put through full malolactic conversion, producing the buttery, tropical style that provoked a backlash severe enough to have its own acronym.

The technical levers are few and powerful: oak or no oak, new or old; malolactic fermentation, which converts sharp malic acid into soft lactic and creates the buttery diacetyl note; and lees contact, which adds texture and savour.

It is genetically a cross between Pinot Noir and Gouais Blanc, a humble medieval variety that turns out to be the parent of a remarkable number of French grapes.

It buds early, making it frost-prone, and otherwise grows almost anywhere, which is the other half of its global success.

The backlash against oaked Chardonnay in the 1990s and 2000s was severe enough to be a commercial phenomenon in its own right, and it produced an equal and opposite overcorrection: a wave of deliberately lean, unoaked wine that stripped out the texture along with the vanilla. Most producers have since settled on older barrels, partial malolactic conversion and lees work that builds body without announcing itself.

Malolactic fermentation is the single most consequential decision. It converts sharp malic acid into rounder lactic acid and produces diacetyl, the compound responsible for the buttery note. Blocking it keeps the wine taut and appley; allowing it fully gives the creamy, buttered-popcorn character that divides drinkers.

Its frost sensitivity is a real agricultural problem rather than a footnote. Chardonnay buds early, and Chablis in particular has a long history of spring frosts wiping out a substantial share of the crop, which is why the vineyards there are dotted with heaters and sprinkler systems.