re-hydrating the yeast

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ctshep97

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how important is it to re-hydrating the yeast as oposed to just sprinkling on the top. i have dove a few kits that say just sprinkle on top and i did 2 strawberrys just sprinkling.i have a blackberry recipe that says to re-hydrating the yeast first .what is the best and what is the best way to re-hydrating the yeast ??????t
 
If you look on the packet it should have directions. If not here is info from Lalvin's website.



Importance of rehydrating yeast
......................................






How important is it to rehydrate the yeast before
adding
it to the fermenter?
Very important! Extensive research shows that the
yeast
cell wall is very fragile during the first few minutes of
rehydration.
Some of the components of the yeast are going from a dry
crystalline form
to a gel like state and can go through this transformation
successfully
if rehydrated properly (refer to our 3 easy steps rehydration
protocol).
With rehydration water at lower temperatures the transformation
from crystalline
to gel is less successful, the cell wall becomes porous and
leaches out
vital parts of its insides. Rehydration in 60°F water can result
in
a loss of 60% of the yeast viability.
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 presence of 1/2% yeast extract, yeast hulls,
autolyzed yeast
or peptone in the rehydration water will give the yeast an added
boost
that will get it through its lag phase quicker. After the yeast
cell wall
has been reconstituted, the yeast returns to its normal ability
to be
selective.
Most fermentations should start with an
inoculation of 3
- 4 million viable yeast cells per milliliter of must. A normal
healthy
fermentation will reach the stationary phase with a cell
population up
to 100 - 150 million viable yeast cells per milliliter. Because
of this
significant increase in biomass, it is critical that the active
dried
yeast gets off to a good start. Winemakers that carefully
rehydrate their
active dried yeast are taking a key preventative step to
avoiding stuck
and sluggish fermentations. Remember to use only clean 104°F tap
water
and please refer to our Easy 3 Steps Protocol for more
information.http://www.lalvinyeast.com/strains.asp

http://www.lalvinyeast.com/index.asp
 
Be on the cautious side and keep the temp down but I either sprinkle dry or make a starter myself.
 
EC-1118 seems to be rather resistant to 'yeast abuse' and responds well to sprinkling directly on top of the must. If you happen to be using a different yeast, it's important to follow the manufacturer's recommended yeast rehydration/starter procedures.


Your main points of concern when making a solid yeast starter would be proper hydration of the yeast (good,non-distilled water at 104 F as stated above in Smurfe's post). It's important not to add any kind of yeast energizer (DAP) to the starter as this could burn the cells of the yeast. After the yeast has sat for 15 minutes, give it a swirl and then check the temperature.


Ideally, the yeast will be happiest if the temperature of the starter is within 10 degrees F of the temperature of the must. If not, you'll want to wait a bit to let things cool down, which makes thisa perfect time to help your yeast to adjust to the sugar/acid mix that they are about to be thrown into. At that original 15 minute mark mentionedin the previous paragraphadd a small amount of the must into the yeast starter comprising of no more than a 25% increase in volume. Wait 5 minutes and then add another equal dose. As the must as added into the yeast starter, it will gently cool down the starter closer to the temperature of the must and will also help the yeast cells acclimate to the chemistry of their new home. Once the starter is within 10 degrees of the must, you'll be ready to go - swirl the starter and pour it into the must; stir to mix.


Remember, if you're using fresh EC-1118, it will do it's thing even you speak badly about it. Other yeast is more sensitive and requires increased attention before and after inoculation.


- Jim
 
Yeast ARE very sensitive - they seem to respond best with lots of verbal encouragement or cheering. Don't insult them by mentioning they make things smell *funny*.

Yuck, yuck, yuck...
 


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