Margalit (1996) identified four key stages in the growth pattern of yeasts, a ‘lag’ period during which the yeast cells become acclimatized to conditions in the must and start multiplying; a period of rapid, exponential growth to a final population of around 2 × 108 cells/ml; a stationary phase during which the number of cells undergoing fission equals those dying, and a decline or death phase in which the number of cells dying exceeds the number undergoing fission. Sugars are metabolized through the first three phases.