CMS Certified Sommelier key terms

A root-feeding, aphid-like insect that kills European grapevines. It swept through Europe in the late 1800s and is managed today by grafting Vitis vinifera onto resistant American root systems.

The root system of an American vine species onto which a Vitis vinifera scion is grafted. It provides resistance to phylloxera and can also adapt the vine to soil type, drought, or high limestone content.

The ripening stage when berries change color, soften, and begin building sugar while acidity drops. It marks the midpoint of the growing season and signals that harvest is approaching.

A bacterial conversion of sharp malic acid into softer lactic acid. It lowers total acidity, adds buttery and creamy notes, and is standard for most reds and for some whites such as Chardonnay.

A technique in which whole, uncrushed grapes ferment inside their own skins in a carbon dioxide–filled tank, yielding fruity, low-tannin reds such as Beaujolais. Intracellular fermentation happens before normal yeast fermentation.

Adding sugar to grape must before or during fermentation to raise the final alcohol level. It is regulated and permitted in cool regions such as Burgundy but banned in many warm-climate countries.

A fungus that, given misty mornings and dry afternoons, shrivels grapes and concentrates sugar and acid into honeyed, complex sweet wines such as Sauternes and Tokaji.

A fractional blending system of stacked barrels in which wine is drawn from the oldest level for bottling and each level is refilled from the next, giving a consistent style. Used for Sherry, Madeira, and some spirits.

A film of yeast that grows on the surface of dry Sherry in barrel, shielding it from oxygen and consuming glycerol and alcohol to create the tangy, saline character of Fino and Manzanilla.

A sparkling wine process in which the second fermentation occurs in the bottle, followed by aging on the lees, riddling, disgorging, and dosage. It produces fine bubbles and yeasty complexity.

A small addition of wine and sugar, the liqueur d'expédition, made after disgorging. It sets a sparkling wine's sweetness level from Brut Nature to Doux and can soften harsh acidity.

Dead yeast cells that settle after fermentation. Aging wine on them adds texture, body, and bready flavors, and stirring them back into suspension intensifies that creamy, yeasty effect.

The combined influence of soil, subsoil, slope, aspect, climate, and local tradition on a wine's character. It explains why a particular vineyard site yields distinctive, recognizable wines.

A genetically identical group of vines propagated from one parent plant and selected for traits such as yield, ripening date, disease resistance, or flavor, giving growers choices within a single variety.

A red-winemaking technique of pushing the floating cap of skins and seeds back into fermenting juice. It boosts color, tannin, and flavor extraction and keeps the cap from drying out.

Adding neutral grape spirit to a fermenting or finished wine to raise alcohol and often preserve sweetness, as with Port, Sherry, Madeira, and Muscat de Beaumes-de-Venise.

A continuous distillation apparatus with stacked plates that separates alcohol from water repeatedly in a single pass. It yields high-strength, lighter-bodied spirit efficiently and is used for most grain and neutral spirits.

The portion of a spirit or fortified wine that evaporates from the barrel during aging. It grows with heat and time and concentrates the flavors left behind in the liquid.

The standard tableside order of operations: present and confirm the bottle with the host, open it, offer the cork, pour a small taste for approval, then pour for guests and serve the host last.

Showing the bottle's label to the guest who ordered it so producer, vintage, and vineyard can be confirmed before opening. It prevents serving the wrong wine and shows professionalism.

Pouring wine from its bottle into a decanter, either to leave sediment behind in older reds or to expose young, tannic wines to air so they open and soften.

The temperature at which a wine is poured, cooler for sparkling and white wines and slightly below room temperature for reds. Warmth exaggerates alcohol and cold mutes aroma.

The procedure for a wine that smells or tastes wrong: confirm the fault discreetly, replace it without argument, and keep the suspect bottle out of service so the guest's experience stays positive.

Methods that keep opened wine fresh for by-the-glass service, including inert gas blankets, vacuum stoppers, refrigeration, and small-format bottles, all of which slow oxidation and extend shelf life.

Opening and pouring sparkling wine safely: chill it well, loosen the cage after removing the foil, grip the cork, twist the bottle gently, and pour down the side of a tilted glass.

Matching a wine to a dish by weighing its body, acidity, sweetness, and tannin against the food's fat, salt, spice, and protein so neither the food nor the wine dominates.

The setup of a service station before guests arrive: polished glassware, openers, napkins, ice, and wines at the correct temperature, so service flows without trips to the back.

The duty to inform guests about major allergens in food and drink, including sulfites in wine and typical fining agents, so they can choose safely.

A structured blind-tasting approach moving from sight to nose to palate, then using the observed acid, tannin, alcohol, sweetness, body, and aroma families to reason toward grape, origin, and age.

The sugar left in a wine after fermentation, measured in grams per liter. It creates sweetness and viscosity and can be masked by high acidity or read merely as richness in dry wines.

The sharp, mouth-watering sensation on the sides of the tongue and inner cheeks that gives wine freshness and structure. It is judged by how much saliva the wine provokes and how long it lingers.

Judging the drying, grippy feel on gums and inner lips from skins, seeds, and oak. A taster notes the amount, the grain, and whether it sits in harmony with acid and fruit.

The three origins of wine aroma: primary from grapes and fermentation, secondary from winemaking such as lees or oak, and tertiary from aging, such as dried fruit, mushroom, leather, or honey.

How long flavor and sensation persist after swallowing. A long finish is a quality marker, and its character, whether acidic, tannic, sweet, or warm, helps confirm grape and origin.

The impression that a wine's acid, alcohol, tannin, sugar, and fruit sit in harmony with no single component sticking out. It is a key quality signal and a clue to age-worthiness.

The degree to which a wine shows the recognized characteristics of its grape, region, and style. A taster uses it to test whether a candidate identification is plausible.

A spoilage yeast that gives wine barnyard, band-aid, and smoky notes along with a drying palate. Small amounts may seem complex, but higher levels bury fruit and are a fault in most styles.

The level of acetic acid and related compounds in wine, perceived as vinegar or nail polish. A little adds lift, but excess points to spoilage bacteria or oxidation and is a fault.

The foam and bubble texture of sparkling wine on the palate. It may be fine and creamy or coarse and aggressive, giving clues to production method and time spent aging.