Clarification

Yeast in wine is a microscopic, single celled fungus, typically Saccharomyces cerevisiae, which triggers fermentation by transforming the sugars in must into ethanol and carbon dioxide. Yeasts are essential for converting grape juice into wine and they determine its final alcohol content, aroma and flavor profile.

Oxidation is a chemical reaction that occurs when oxygen in the air comes in contact with the alcohol in wine, converting ethanol into acetaldehyde, then acetic acid. It causes wines to lose their vibrant colors and reduces fresh fruit aromas.

Assemblage is the French term for the process where winemakers combine different base wines that vary by grape variety, vintage or vineyard parcel, to create a balanced and complex final wine.

The yield signifies the amount of grapes or wine produced from a specific vineyard area, commonly measured in tons per acre in the US, or hectoliters per hectare in Europe. Lower yields are associated with better quality, while higher yields produce lighter and less concentrated wines.

The pH of wine is the measure of its total acidity (hydrogen ion concentration), typically ranging from 2.9 to 4.0 in most wines.

Grape must is the freshly pressed, unfermented grape juice which contains the fruit's skins, seeds and sometimes stems (collectively referred to as pomace).

The Crush refers to the period in late summer or fall when harvested grapes are mechanically broken to rupture their skins and release the juice, initiating the winemaking process.

Lees are the dead yeast cells, grape seeds and skins left over in the fermentation tank after fermentation. There are two types of lees; gross lees and fine lees.