Yeast

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.

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.

The harvest marks the end of the vine growing cycle, typically occuring between August and October in the Northern hemisphere. It is the stage where ripe grapes are picked from the vineyard to begin winemaking.

Fermentation is a natural biochemichal process where yeast consumes the natural sugars in grape juice and converts them into alcohol, carbon dioxide and heat. At the end of fermentation, grape juice is converted into wine.

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

Sulfites (sulfur dioxide or SO₂) are chemical compounds naturally produced by yeast during wine fermentation. They act as preservatives, also commonly added by winemakers to prevent bacterial growth, spoilage and oxidation.

Viticulture is the branch of science that deals with the study, cultivation and harvesting of grapes specifically for winemaking. It includes all vineyard activities, such as planting, pruning, training vines, soil irrigation and pest control.

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.