WINE YEAST RE-HYDRATION and
We have just read on
thewww.lalvinyeast.com site that rehydration in distilled or
de-ionized water is LETHAL to the yeast.
with your chosen yeast 1-2 days after adding potassium metabisulfite.
Fill your fermenter (container carboy, food grade bucket or pail) with juice
or crushed grape "must". Crushed grapes go in the bucket, never a carboy. If using a carboy, which is a
gallon-jug-shaped glass or PET wine safe plastic carboy, fill the juice to the shoulder. Place the balance of
your juice in a gallon jug or spit the juice between two carboys or use a bucket that will hold all. The
initial or primary fermentation needs a little headroom for activity.
Make a yeast selection based on the properties of the yeast and your desired
results in the wine type or finish.
Prepare your yeast. The least you need to do with yeast preparation is to
re-hydrate the yeast as indicated on the back of most yeast packs. Re-hydrate with non-chlorinated
water. We have just read on the lalvin site that rehydration in distilled or deionized water is
lethal to the yeast. The cell walls require the presence of some minerals, sodium, calcium,
magnesium and or potassium, during rehydration. Tap water at 250 ppm hardness is optimum. Most tap water has
enough hardness to do the job.
the dry yeast to ¼ cup or about 50 ml of warm, not hot water: 40-43 degrees C or 104-109 degrees F.
Temperature recommendations may vary by brand or type of yeast. Let stand for 15 minutes without
stirring, and then stir well to suspend all the yeast. Combine an equal amount of must or juice to be fermented. This will help the yeast to adjust to
the cool temperature must. This "atemperation" may need repeating in very low temperature must. Add immediately to
must or juice that is room temperature. Our juices and some grapes have been refrigerated. Let them come up to room
temperature before inoculation. Add the re-hydrated yeast to
previously (1-2 days earlier) sulfited must or juice. IThe yeast will start expanding and will disperse.
The time from inoculation to the start of visible fermentation is called
lag. The lag time ends when the fermentation starts.
When the lag time ends is the time to dose the juice with half of the
recommended amount of Fermaid K.