rehydrating yeast

[Lauritsen]

When rehydrating a yeast in lukewarm water before pitching it in - do you add the nutrient to this water?

Or do you add it to the must?

whats your procedure?

 

[FortMillBrew]

I have never rehydrated dry yeast for wine as it is not necessary. For beer, always.
If you insist, I would add the nutrient to the must not the rehydration solution.

 

[theDREWery]

Adding nutrients, especially DAP, to rehydration water can damage cell walls. The only thing to add to hydration water would be Go Ferm, or something specifically formulated for rehydration.

 

[Mismost]

follow the instructions on the yeast package, I figure the manufacture knows way more about yeast than we do. I always rehydrate, always get results.

 

[pumpkinman2012]

The following is taken straight from Scott Labs fermentation handbook:

Proper yeast rehydration is one of the most important steps to help ensure a strong and healthy fermentation. Normal inoculation for wine active dried yeast is 2 lb/1000 gal (25 g/hL). (approx 1 gram per gallon of must) When added properly, a 2 lb/1000 gal (25 g/hL) (1 gram per gallon) addition of wine active dried yeast results in an initial cell concentration of 3-4 million viable cells per milliliter of must/juice. Under favorable conditions, the initial cell population may increase up to 100-150 million viable cells per milliliter of must/juice before growth stops and alcoholic fermentation begins.
This biomass increase is critical for healthy fermentations..

This shows that rehydrating yeast is extremely important cell grown and reproduction, the larger and healthier the yeast is, the better fermentation will be.
Add the dry yeast to water that is at 104°, mix gently and wait approx 5-10 mins to add a nutrient, I use some of the must or grape juice that I'll be fermenting, I'll heat it to 90° and add it gently to the must. this will not only temper your yeast, but it will give your yeast the necessary nutrients that they need to multiply and reproduce, creating a colony that will be the dominant yeast that will ferment your must properly.