Wine Dictionary M to O

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Maceration: The process of allowing grape juice and skins to ferment together, thereby imparting color, tannins, and aromas.

Made and Bottled By: On U.S. labels, this indicates only that the winery crushed, fermented and bottled a minimum of 10 percent of the wine in the bottle.

Madeira: A fortified wine that has been made on a Portuguese island off the coast of Morocco since the fifteenth century.

Maderized: Stemming from the word Madeira, it means the oxidation in a hot environment.

Magnum: An oversized bottle that holds 1.5 liters.

Malbec: A hearty red grape of French origin now exceedingly popular in Argentina.

Malic Acid: one of the three predominate acids in grapes. It’s tart-tasting and occurs naturally in several fruits, including, apples, cherries, plums, and tomatoes.

Malolactic Fermentation: A bacterial conversion occurring in most wines, this natural process converts sharper malic acid into softer lactic acid. Total acidity is reduced; the wines become softer, rounder and more complex.

Marc: See Pomace.

Masculine: Describes wines with firmness, power, and strength.

Mature: The stage at which the wine will not gain any additional complexity with further bottle aging and is ready to drink. Also, describes grapes when they are fully ripe.

Meaty: Describes red wines that show plenty of concentration and a chewy quality. They may even have an aroma of cooked meat.

Medoc: A section of Bordeaux on the west bank of the Gironde Estuary known for great red wine; Margaux, St. Estephe, and Pauillac are three leading AOCs in the Medoc.

Meniscus: The thin rim at the edge of a wine’s surface where the wine meets the glass.

Mercaptans: Also, known chemically as thiols, organosulfur compounds that emit unpleasant, skunky aromas of rubber, sulfur or garlic.

Meritage: An invented term, used by California wineries, for Bordeaux-style red and white blended wines. Combines “merit” with “heritage.”

Merlot: A lauded red grape popular in Bordeaux and throughout the world; large amounts of Merlot exist in Italy, the United States, South America, and elsewhere.

Méthode Ancestrale: The French term for Ancestral Method.

Méthode Traditionnelle: The labor-intensive process whereby wine undergoes a secondary fermentation inside the bottle, creating bubbles. All Champagne and most high-quality sparkling wine are made by this process. Also, Méthode Champenoise and Méthode Classique.

Methuselah: An extra-large bottle holding 6 liters; the equivalent of eight standard bottles.

Microoxygenation: This technique, used almost exclusively on red wines, allows winemakers to control the amount of oxygen that wines in tank are exposed to. Microoxygenation is also believed to soften tannins and, in conjunction with the use of oak chips, is frequently practiced as an alternative to oak barrel aging.

Millerandage: Also, known as “hens and chicks,” an irregular fruit set in which the berries on a grape cluster are not uniform in size, with some achieving full size while others remain tiny and seedless.

Mis en Bouteille: French term meaning put in bottle. Featured on the back of a wine label, succeeded by the name of the estate where the wine was bottled.

Monopole: An appellation or other designated wine growing region controlled entirely by one winery.

Mousse: The frothy head that forms at the surface of sparkling wine.

Mouthfeel: Describes the sensation of wine in the mouth. Most descriptors are related to texture, for example: silky, smooth, velvety and rough.

Multi-Vintage: See Non-Vintage.

Murky: Describes a wine that is lacking brightness, turbid, and sometimes a bit swampy.

Must: The unfermented juice of grapes extracted by crushing or pressing; grape juice in the cask or vat before it is converted into wine.

Must Weight: Measurement of the sugar content in grape must, or unfermented grape juice, which indicates the potential alcohol of the juice were all the sugar to be converted to alcohol during fermentation.

Musty: Having an off-putting moldy or mildewy smell. The result of a wine being made from moldy grapes, stored in improperly cleaned tanks and barrels, or contaminated by a poor cork.


Nasal Fatigue: Diminished sensory perception; not uncommon after sniffing the same scent a number of times.

Native Yeast: See Yeast.

Natural Yeasts: They occur naturally on the grapes, rather than commercially cultured yeasts; both are used for fermentation.

Nebbiolo: A red grape popular in the Piedmont region of northwest Italy; the grape that yields both Barolo and Barbaresco.

Nebuchadnezzar: A giant wine bottle holding 15 liters; the equivalent of 20 standard bottles.

Négociant/Négociant-Éléveur: Stems from the French word for “shipper”, it’s the French term for a person or company that buys wines from others and then labels in under his or her own name.

Nevers: A forest in France that produces hard, medium-grained oak for barrels.

New Oak: Refers to the first time a barrel is used, when it has the greatest impact on wine.

New World: The New World is comprised of countries that have started producing wine more recently than the countries of Europe, including the United States, Australia, New Zealand, Chile, Argentina and South Africa.

Noble Rot: The common term for Botrytis Cinerea, is a beneficial mold that grows on ripe wine grapes in the vineyard under specific climatic conditions.

Noble Varieties: Considered the classic grape varieties, originating in the Old World, which have the ability to make outstanding wines. Reds include Merlot, Cabernet Sauvignon, Nebbiolo, Pinot Noir, Sangiovese, and Syrah. Whites include Chardonnay, Chenin Blanc, Gerwürztraminer, Riesling, Sauvignon Blanc, and Sémillion.

Non-Vintage: A wine blended with grapes grown in more than one vintage.

Nose: A tasting term describing the aromas and bouquets of a wine

Nouveau: A style of light, fruity, youthful red wine bottled and sold as soon as possible.

Nutty: Describes oxidized wines.


Oak Chips: Some popularly-priced wines are aged with small pieces of wood to gain oaky flavors, instead of gaining complexity in expensive oak barrels while aging. See Beans.

Oaky: Describes the aroma and flavors of vanilla, baking spices, coconut, mocha, or dill caused by barrel-aging.

Oechsle: A scale used in Germany to measure sugar levels and other solids in grapes or must to determine ripeness and potential alcohol. This scale is based on the density or specific gravity of the must. See Baumé and Brix.

Oenology: See Enology.

Open: Describes a wine that is ready to drink

Oxidation: A wine exposed to air that has undergone a chemical change.

Off-Dry: Indicates a slightly sweet wine in which the residual sugar is barely perceptible.

Oïdium: Also, known as powdery mildew, a fungal disease that infects areas of green growth on grape vines, particularly Vitis vinifera varieties. Grapes afflicted with the powdery or cobweb-like fungus are generally discarded.

Olallieberry: A hybrid berry resulting from the crossing of loganberry and youngberry, all of which are descended from the blackberry.

Old Vine: Some wines come from vines that are 50, 70, or even 100 years of age, which yield small quantities of concentrated fruit, and make a more concentrated and complex wine.

Old World: The Old World refers to the countries of Europe where winemaking dates back centuries.

Olfactory Epithelium: A dime-sized patch of nerve endings situated in the retronasal passage that connects the nose to the mouth. As we inhale through the nose or mouth, this little patch captures airborne aromas and flavors as they pass by and transmits the information to the olfactory bulb, which can distinguish the presence of and identify nearly 10,000 unique aromas even at very low concentrations.

Oloroso: Oloroso is the darkest, richest category of dry Sherry.

Optical sorter: A machine with an optic sensor that recognizes and removes non-standard grapes based on size, shape, and/or color with a puff of air.

Orange wines: White wines made with extended grape skin contact during fermentation or maceration, imparting an orange hue to the finished wine, along with tannins.

Organic Wine: The rules and methods for producing organic grapes and wine are still evolving. In most cases, organic wines are fermented from grapes grown without the use of synthesized fertilizers, pesticides or herbicides. In organic wines, natural yeasts and minimal amounts of sulfur are often used in the fermentation process.

Ouillage: The French term for ullage—the volume of air inside a wine bottle or barrel—as well as for the process of topping off a barrel with additional wine to fill the ullage created by evaporation.

Oxidative: Refers to winemaking practices that deliberately expose the wine to oxygen, such as the use of open-top fermentors and racking.

Oxidized: Describes wine that has been exposed too long to air and taken on a brownish color, losing its freshness and perhaps beginning to smell and taste like Sherry or old apples. Oxidized wines are also called maderized or sherrified.