RE-HYDRATING &

RE-HYDRATING & ACCLIMATING

ACTIVE DRY YEAST

Unrehydrated active dry yeast are extremely sensitive to cold-shock.

Also, after re-hydration, yeast are very sensitive to being added to must/juice that is below 68*F. Failure to address these two situations will result in extensive loss of yeast viability….and subsequent slow starts, sluggish ferments, and stuck fermentations.

REHYDRATING ACTIVE DRY WINE YEAST:

         (Use 5 grams of yeast/5 gallons of juice)

        (Use 10 grams of yeast/100 lbs of grapes)

                  (For each 5 grams of yeast)

Mix 2 teaspoons (6.3 grams) GO-FERM in

           4 ozs. of 100*F/38*C water.

   Do not guess. Use a thermometer.

Sprinkle the dry yeast onto the GO-FERM solution.

Let stand, covered, for 10-15 minutes (never more than 30 minutes). Then stir and add to must that is not below 68*F.

ACCLIMATING TO MUST/JUICE TEMPERATURE:

If it is necessary to inoculate

must/juice below 68*F/20*C:

1. Add a small amount of well aerated cold juice to the re-hydrated yeast…to bring the yeast mix down

no more than 10*F/5*C.

2. When some fermentation activity is seen (10-30 minutes), add another portion of well aerated cold juice to the yeast mix, again dropping the temperature no more than 10*F/5*C.

3. Repeat until the yeast mix is no more than

5*F/2*C warmer than the main must/juice,

then add this mix to start the fermentation.

Do not let the yeast mixture ferment too long, it weakens the yeast.

For must/juice below 60*F/15*C, a higher yeast dose is recommended

to make up for cell mortality, which can be more than half the cells.

Unfortunately, cold-soaked red must or cold-settled white juice is often inoculated with yeast while it is still cold, killing most of the yeast.

It is much better to warm the must/juice to at least 60*F/15*C,

inoculate, then cool to desired fermentation temperature.

This warming, inoculating, and cooling should be done rapidly….to prevent the build up of ethyl acetate (nail polish smell) from wild yeast.