ISG Sommelier key terms

French certification that ties a wine's name to a defined geographic area, approved grape varieties, and mandated production rules, with the INAO auditing compliance. It guarantees origin and method rather than quality ranking.

EU quality scheme protecting a food or wine name whose production, processing, and preparation must all occur within a named region under a published specification. Equivalent to French AOC and Italian DOCG in legal effect.

EU label protecting a product name where at least one production stage happens in the named region, allowing more flexibility than PDO. Many European table wines with regional names sit at this tier.

The combined influence of site-specific factors - soil, slope, aspect, climate, and local tradition - on a wine's sensory character. It is the conceptual basis for geographic labeling and single-vineyard bottlings.

The process of matching grape variety, rootstock, and training system to a plot's soil, drainage, slope, and mesoclimate. Good selection reduces vintage variation and supports consistent ripeness.

The seasonal sequence of budbreak, flowering, veraison, and harvest, tracked as accumulated heat. Growers use it to time canopy work and picking, and to judge whether sugar and phenolic ripeness will align.

The stage when seeds, skins, and stems have matured alongside sugar accumulation, giving ripe tannins and developed aromas. Picking on sugar alone can leave harsh tannin and green flavor.

The transition when grapes soften and change color, reds from green to purple and whites from green to translucent. It marks the start of ripening and is used to forecast harvest timing.

A bacterial conversion of sharp malic acid into softer lactic acid, usually in reds and some whites. It lowers perceived acidity, adds buttery or creamy notes, and increases microbial stability after fermentation.

The conversion of grape sugars into ethanol and carbon dioxide by yeast, generating heat and aroma compounds. Temperature, yeast strain, and nutrient levels strongly shape the finished wine's style.

Leaving wine in contact with dead yeast cells after fermentation, sometimes with periodic stirring. It builds body, creamy texture, and savory complexity, and can bind harsh compounds in the wine.

The practice of stirring wine with its lees to suspend the sediment and increase extraction of texture and flavor. It is common in white and sparkling wines made in a rich style.

Sugar remaining in wine after fermentation stops, whether by cooling, filtration, or alcohol tolerance limits. It balances acidity and shapes the wine's perceived sweetness and body.

The total acid content of a wine, measured by titration and expressed as tartaric acid equivalents. It drives freshness, affects stability, and is a key balance point against sugar and alcohol.

A measure of hydrogen ion concentration, indicating how strongly acidic a wine is on a logarithmic scale. Lower pH improves color and microbial stability and sharpens perceived freshness.

Acetic acid and related compounds detectable as vinegar or nail-polish notes, measured in grams per liter. Small amounts add lift; excess signals spoilage or oxidation and is legally limited.

Polyphenolic compounds from skins, seeds, stems, and oak that bind proteins and create drying, grippy sensations. Tannin structure and ripeness determine a wine's texture and aging potential.

Maturation in barrels or with oak alternatives that adds aroma compounds, gentle oxygen exposure, and tannin. Vessel size, toast level, and age all change the resulting style.

Deliberate, controlled oxygen addition during winemaking to soften tannin and stabilize color. It mimics slow barrel breathing and is used to polish reds before bottling.

Damage from excess oxygen exposure, showing as dull color, nutty or sherry-like aromas, and flattened fruit. It is distinct from intentional oxidative styles such as tawny Port.

The lowest concentration at which a compound can be detected or recognized, varying widely between individuals. It explains why a fault level in one taster's range may be invisible to another.

Evaluating a wine without seeing its label, using appearance, nose, palate, and deduction to identify grape, origin, and style. It is a core sommelier skill and a standard exam format.

A structured framework that records sight, nose, palate, structure, and conclusions in consistent order. It forces systematic observation and makes comparative judgments more reliable.

The recommended serving range for a wine, chosen to balance aroma release, acidity, alcohol, and tannin. Sparkling and light whites are served coldest, full-bodied reds warmest.

Pouring wine into a wider vessel to separate it from sediment or to aerate it before service. Sediment decanting is brief; aeration is longer and mainly benefits young, tannic reds.

Choosing bowl shape, rim diameter, and stem to direct a wine's aromas and delivery on the palate. The right glass concentrates the intended characteristics and supports consistent tasting.

Guidelines matching food and wine by weight, acidity, sweetness, tannin, and intensity, with attention to salt, fat, and spice. Balance and contrast matter more than rigid rules.

The ordered steps of presenting, opening, pouring, and checking a bottle at the table, including showing the label and offering a taste to the host. Consistency protects the guest experience.

A wine list strategy offering selected wines in single servings, managed for freshness, cost, and margin. Preservation systems, pour cost, and staff training determine its profitability.

The cost of the wine poured divided by its selling price, expressed as a percentage. Operators use it to set glass prices and monitor whether a program meets margin targets.

Tracking purchasing, storage, pouring, and waste to keep beverage costs within budget. It relies on regular inventory counts, standardized recipes, and variance analysis.

How many times stock is sold and replaced over a period, calculated from cost of goods and average inventory. It signals dead stock, over-ordering, or healthy demand.

Carbohydrates, proteins, and fats that supply energy and building materials in the diet. Sommeliers reference them when discussing food pairing, portion balance, and dietary accommodations.

The liver's breakdown of ethanol, mainly via alcohol dehydrogenase, at a limited and fairly constant rate. It explains intoxication risk, standard-drink guidance, and why food slows absorption.

A defined measure of pure alcohol used for consumption guidance, varying by country. Knowing it lets staff translate a glass of wine into a comparable alcohol dose.

Sulfur dioxide added or naturally produced during winemaking to prevent oxidation and microbial spoilage. Levels are regulated and labeling rules differ by market, so allergy questions need accurate answers.

The US regulatory model separating producers, wholesalers, and retailers, with most wine passing through a licensed distributor. It shapes pricing, market access, and how brands reach restaurants.

A government tax levied per unit of alcohol or per volume on wine production or import. It varies by country and directly affects shelf and list prices.

The paperwork required to move wine across borders, including commercial invoice, customs declaration, origin certificate, and health or analysis certificates. Errors cause delays, fines, or refused shipments.

A loose market and style distinction between traditional European producing regions and newer producers elsewhere. It is useful shorthand for labeling law and style trends but often oversimplifies modern winemaking.