Maceration

Process of steeping grape skins in their juice, to extract flavour and, in the case of reds, colour and tannin. Essential for red wines, the maceration may last between a few days and a few weeks. Optional for whites, and usually limited to a few hours.

Maderized

A wine that has become over-mature, oxidised, and with a cooked taste.

Magnum

Bottle of 1.5 litres, equal to 2 normal (75cl) bottles.

Malic acid

See 'acids', 'malolactic fermentation'.

Malolactic fermentation

Transformation (not technically a fermentation at all) in which the tart tasting malic acid present in young wine is transformed into the softer lactic acid. Normal for reds, but optional for whites. Whites that have undergone malolactic can have a distinctive buttery taste.

Marc (Fr.)

Solids, such as dry skins and pips, left after pressing. Also used to describe the spirit made by distilling the marc.

Mature

Tasting term indicating a wine that has aged sufficiently to be ready to drink at its best.

Mature

A wine that has aged sufficiently to be ready to drink at its best.

Methode champenoise (Fr.)

Champagne method. Sparkling wines made by this method undergo the second bubble-forming fermentation in the actual bottle in which they will be sold. The term was formerly used on labels of sparkling wines from outside Champagne, but has now been replaced by methode traditionnelle, and local equivalents.

Methode traditionnelle (Fr.)

Traditional method (of making sparkling wines). Sparkling wines made by this method undergo the second bubble-forming fermentation in the actual bottle in which they will be sold. The term is widely used on labels of sparkling wines from outside Champagne.

Methuselah

Bottle of 6 litres capacity, equivalent to 8 normal (75cl) bottles, used mainly for Champagne.

Millesime (Fr.)

Vintage.

Mistelle

Alcoholic drink made by adding brandy to unfermented grape juice. Examples include Floc de Gascogne, Pineau des Charentes, Ratafia.

Mousseux (Fr.)

Sparkling. Usually indicates that the wine was made by the Charmat method rather than the methode traditionnelle.

Musky

A floral, perfumed aroma, typical of aromatic grapes of the Muscat family.

Must

In winemaking, the mixture of grape skins and grape juice that results after crushing but before fermentation has transformed it into wine.

Must weight

Measure of the amount of sugar in the must. This gives a guide to what the final alcohol content will be. See 'Baum', 'Brix', 'Oechsle'.

Musty

A stale, unpleasant aroma.