40,000

Number of yeasts that could fit on the head of a pin. Yeasts, which convert sugar in grapes to alcohol in wine, are single-cell members of the fungus family. Various strains of yeasts exist naturally in vineyard soils, cling to the skins of grapes, and are present in the air and on surfaces in wineries. Yeasts reproduce themselves by “budding.” One mother yeast cell will bud about 12 times, creating a new daughter cell each time.