Proper Handling Of Active Dried
Wine Yeast.
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"Kilgore
Trout once wrote a short story which was a dialogue
between two pieces of yeast. They were discussing
the possible purposes of life as they ate sugar
and suffocated in their own excrement. Because
of their limited intelligence, they never came
close to guessing that they were making champagne."
- Kurt Vonnegut, Breakfast of Champions
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| Fermentation
is the process by which a microorganism (yeast) converts
sugar into alcohol and carbon dioxide gas. All winemakers
know that yeast is not an ingredient like sugar, tannin
or SO2, but is a living organism whose role is so
critical that without it, no wine, beer or spirit
is possible. |
| Proper
rehydration is perhaps the most critical phase in
using dried yeast. When we produce Lalvin wine yeast
and Danstar beer yeast, we grow it to permit efficient
drying with minimal loss of living cells. The drying
stage removes not only extracellular water, but most
of the water within the cell and bound to the cell's
organelles. In the dryer, the yeast cells shrink and
desiccate - a very stressed state for a living organism. |
| To be
functional again, the dried yeast cells must reabsorb
all their water. When the dried yeast comes in contact
with water (or any other liquid) the cells literally
act like dried sponges and suck up the needed water
in seconds (water uptake). Not only will yeast cells
not disperse very well if not properly rehydrated,
they can lose a large amount of cytoplasm, reducing
the efficiency of oxygen and nutrient transfer to
the cells. This impedes growth and activity (sluggish
or stuck fermentations). Proper rehydration can ensure
healthy yeast cells and good fermentation characteristics. |
Three
Easy Steps
|
| 1.)
For best results, rehydrate active dried wine (or
beer) yeast by opening the 5 gram sachet and pouring
contents into 50 mL (1/3 cup) clean 40°C (104°F)
water. |
| 2.)
Stir lightly and allow the yeast suspension to stand
for at least 15 minutes but no longer than 30 minutes,
then stir again. |
| 3.)
Then pour the yeast suspension (inoculation) into
the juice or must (or wort, if brewing beer) to start
the fermentation. |
