Why does Jura Savagnin and Chardonnay taste like that?

Characteristically very low tannin, high acidity and medium-full body. Commonly associated with green walnut, curry leaf, green apple, almond.

Not claiming: That every wine from this variety shows these characteristics. This is the range across the category, and site and winemaking move wines within and beyond it.

Characteristically very low tannin, medium-plus acidity and medium-full body. Commonly associated with green apple, lemon, white peach, pineapple.

Not claiming: That every wine from this variety shows these characteristics. This is the range across the category, and site and winemaking move wines within and beyond it.

Cooler growing-season temperatures are associated with slower sugar accumulation and with higher retained acidity, because malic acid is respired more slowly at lower temperatures — particularly at night.

Varies: Season length matters as much as temperature. A long cool season can ripen fruit fully while retaining acidity; a short one may not ripen it at all.

Not claiming: That climate puts flavours into grapes. Climate acts on the vine’s physiology, and the picking decision then determines what reaches the bottle.

A wide day–night temperature range is associated with better acid retention, because cool nights slow the respiration that consumes malic acid while warm days continue to ripen the fruit.

Not claiming: That altitude or continentality guarantees high acidity. Both widen diurnal range on average and neither determines the outcome.

Vanillin and oak lactones are extracted from oak into the wine, in quantities that fall sharply with each use of a barrel.

Varies: Species, grain, seasoning, toast level, barrel size and the age of the barrel all change what is extracted and how much.

Not claiming: That oak produces buttery character. That comes from malolactic fermentation. Nor that a given oak origin yields a given flavour.

Ageing wine beneath a living film of yeast, which protects it and transforms it.

Not claiming: That every producer of this style uses this method, or that using it is required.

Slow oxygen ingress through the staves and bung promotes polymerisation of tannins and anthocyanins, which stabilises colour and is generally associated with a softer perception of tannin.

Not claiming: That an old barrel is equivalent to a steel tank. Aromatic extraction falls with use; oxygen permeability does not.

Prolonged contact with air produces acetaldehyde and, over longer periods, sotolon, associated with walnut, curry leaf and dried-fruit characters.

Not claiming: That these characters indicate a fault. In oxidatively aged styles they are the intended result.

The two philosophies age quite differently. Topped-up (ouillé) whites are best at five to ten years; wines aged under a film of yeast (sous voile) are effectively indestructible and are frequently better after twenty.

Not claiming: That a wine of this style will develop these characters. Ageing potential varies by producer, vintage and storage, and most wine is better young.