Easy Steps for Optimal Yeast Rehydration for Anchor Yeast


Proper yeast rehydration is one of the most important steps to help ensure a strong and healthy fermentation. Due to the unique nature of the Anchor yeast strains, Anchor has developed a yeast rehydration protocol that is best suited for their particular strains. Furthermore, Anchor counsels that use of supplementary nutrients at this stage with their yeasts is not always needed due to the natural vigor of their particular strains. Common sense must be exercised. Normal inoculation for wine active dried yeast  is 2lb/1000 gal (25 g/hL). When added properly, a 2 lb/1000 gal(25 g/hL) addition of wine active dried yeast results in an initial cell concentration of 3-4 million viable cells per milliliter of must(juice). Under favorable conditions, the initial cell population may increase up to 100-150 million viable cells per milliliter of must(juice) before growth stops and alcoholic fermentation begins. This biomass increase is critical for healthy fermentations. Careful rehydration, attention to temperature, and proper inoculation dosage are all important to help prevent sluggish or stuck fermentations.

  1. To inoculate 1000 gallons of must(juice), add 1 kg (2.2 lb) of yeast to 2.6 gallons of warm water or water/juice mixture. Use 30%(SO2 free) juice in the mixture. Temperature of the water/juice mixture must be 35-38° C(95-100°F).
  2. Let suspension stand for 10-20 minutes.
  3. Stir gently to disperse the yeast.
  4. Cool to within 10°C(18°F) of the juice temperature by slowly adding an equal volume of juice into the yeast mixture. Stir and hold for 20 minutes. This will help the yeast adjust to the cool temperature of the must(juice) and will help avoid cold shock caused by a rapid temperature drop exceeding 10°C(18°F). This step also helps the yeast adjust to the sugar concentration, helping to avoid osmotic shock. 
  5. Repeat atemperation step until inoculum is within 10°C(18°) of the juice temperature.