One milliliter of blueberry must was aseptically transferred to a conical tube and diluted serially with 9 ml of sterilized saline water (0.85% NaCl). The yeast count was determined by growing yeast in YM agar (Difco, Sparks, MD, USA) and by incubating at 30 °C for 48 h. Tests were carried out in duplicate, and the results were expressed as log cfu/ml.