Wine Yeast Rehydration
Wine Yeast Rehydration Instructions
Yeast Rehydration Instructions for Winemaking
(Based on the instructions from Scott Laboratories.)
1. Tap water is the best choice for rehydrating yeast. Do not use distilled water, especially if you are not using Go-Ferm. If you want to use bottled water, pick one with some mineral content. We recommend keeping the rehydration process covered as much as possible to keep airborne microorganisms out. We also recommend that everything used in this process be sanitized.
2. Use 25 ml (.85 oz.) of water and 1.25 g. Go-Ferm per 1 g. of yeast. It is recommended to use 1 g. of yeast per 1 gallon of must/juice for sugar levels up to 25° Brix. If the Brix of your must or juice is over 25° Brix, increase rate of yeast to 1.2 g. per gallon, Go-Ferm to 1.5 g. and water to 30 ml for every gallon of must/juice. For example if you have 30 gallons of must at 26° Brix, use 900 ml water, 45 g. of Go-Ferm, and 36 g. yeast.
3. If using Go-Ferm, heat water to 110° F. If not using Go-Ferm, heat water to 104° F. We prefer to boil the water and let it cool to 104° F to help eliminate chlorine and kill any microorganisms in the water. However, this is not necessary.
4. Once the temperature is in the 100-104° F range, add yeast. Stir gently to break up any clumps and let sit for 15-30 minutes. Stir gently again. Do not let sit for more than 30 min.
5. In order to acclimate the yeast, which is warmer, to the temperature of the must/juice, which is generally cooler, it is recommended to slowly (over a period of 5 min.) add an equal volume of the must/juice to the yeast starter. For example, if you are using 10 g. of yeast have 250 ml. of water, slowly add 250 ml must/juice to the yeast.
6. This “atemperation” process should be performed once for every 18° F difference in temperature. For example, if you are inoculating 68° F must with 104° F yeast starter, this step should be performed twice. The idea is to get the temperature of the yeast to within 18° F of the temperature of the must.
7. Let the yeast mixture sit for 20 min. during each “atemperation” step.
8. Add yeast mixture to the must/juice and stir well.