J

Jeroboam
A large bottle holding three litres, the equivalent of four regular wine bottles.
Jug wine
American term for inexpensive table wine.

K

Kosher wine
Wine that is produced under the supervision of a rabbi so as to be ritually pure or clean. Although commonly sweet, it need not be so.

L

Late harvest wine
Also known as late picked, wine made from grapes that have been left on the vine longer than usual. Usually an indicator for a very sweet or dessert wine.
Lees
Wine sediment that occurs during and after fermentation, and consists of dead yeast, grape seeds, and other solids. Wine is separated from the lees by racking.
Legs
The tracks of liquid that cling to the sides of a glass after the contents have been swirled. Often said to be related to the alcohol or glycerol content of a wine. Also called tears.
Lightstruck
A tasting term for a wine that has had long exposure to Ultraviolet light causing “wet cardboard” type aroma and flavour.
Litre (US – Liter)
A metric measure of volume equal to 33.8 fluid ounces (U.S.) or 35.2 fl oz (imperial).
Look
A tasting term for the casual sensory evaluation of a wine.

M

Maceration
The contact of grape skins with the must during fermentation, extracting phenolic compounds including tannins, anthocyanins, and aroma.
Madeirized
A wine showing Madeira-like flavour, generally evidence of oxidation. Sometimes used to describe white wine that has been kept long past its prime.
Magnum
A bottle holding 1.5 litres, the equivalent of two regular wine bottles.
Malolactic fermentation
Also known as malo or MLF, a secondary fermentation in wines by lactic acid bacteria during which tart tasting malic acid is converted to softer tasting lactic acid.
Marc
French for “fruit skins”. See “pomace“.
Master of Wine
A qualification (not an academic degree) conferred by The Institute of Masters of Wine, which is located in the United Kingdom.
May wine
A light German wine flavored with sweet woodruff in addition to strawberries or other fruit.
Merlot
Merlot is a variety of wine grape used to create a popular red wine.
Mis en bouteille au château
French for “bottled at the winery“, usually in Bordeaux.
Mead
A wine-like alcoholic beverage made of fermented honey and water rather than grape juice.
Méthode Champenoise
Process whereby sparkling wines receive a second fermentation in the same bottle that will be sold to a retail buyer. Compare with Charmat or bulk fermented.
Methuselah
A large bottle holding six litres, the equivalent of eight regular wine bottles.
Microoxygenation
The controlled exposure of wine to small amounts of oxygen in the attempt to reduce the length of time required for maturation.
Midpalate
A tasting term for the feel and taste of a wine when held in the mouth.
Millerandage
A French term referring to a viticultural problem in which grape bunches contain berries of greatly differing size and levels of maturity. Caused by cool weather during flowering.
Mud
See “Lees”.
Mulled wine
Wine that is spiced, heated, and served as a punch.
Must
Unfermented grape juice, including pips, skins and stalks.
Must weight
The level of fermentable sugars in the must and the resultant alcohol content if all the sugar was converted to ethanol.