Dry Yeast-To Rehydrate or Not to Rehydrate.

[whywhyzee]

Would like to hear from the board on the pros/cons of Rehydrating Dry Yeast or just pouring the dry yeast from the pack directly into the primary. My understanding is that the dry yeast wall is quite fragile and may not tolerate wort for rehydration as well as using tap water at 95-100 degrees.

[Stinkfist]

I didn't know there were benefits to not rehydrating?

[DannyW]

I sometimes don't rehydrate because it takes some time and adds some risk.

You are supposed to boil some water, let it cool to ~95F (you will kill your yeast at ~110F), add your yeast without stirring, wait 15 min, stir, then add several ml of your cooled wort at 5 min intervals to slowly bring the yeast down from 95F to your pitching temp. That's 30min to an hour by the time you are all done with it.

On the other hand, you could snip off the top of the pouch and sprinkle the yeast on the foam left over from aerating. Do not stir, just walk away. That's 5 seconds by the time you are all done with it

If I am doing a big beer I will go through the long steps. For a regular ~1.050 beer I will usually do the quickie.

[TheDarkSide]

I don't rehydrate and never have any problems with fermentation. Taste, aroma, general drinkability...now that's a different story but I don't think that has anything to do with rehydrating yeast.

[BlueLoon]

Yeast can not control what comes across the cell boundary when dehydrated so you will get more die off when pitching into wort. Re-hydration saves yeast lives! Besides, Jamil says re-hydrate and he is the pope.

If you microwave water while starting your boil it should cool down by the time you need to pitch. I do that and cover it with tin foil and check the temp every now and then. Then dump the yeast in.

[joshhops]

When I rehydrate the yeast I get a really short lag time, around 3 hrs. Compared to the 10-12 hrs from just sprinkling. I'm not sure if my extremely short lag time is a good thing, but my brews turn out great to my taste.

[cheezycow]

+1 on proper rehydration. Cell walls have low tolerance when dehydrated. Cell death and or lag time is certain. Also depending on style this may hurt the pitching rates.

[captain carrot]

I pitch my dry yeast into a starter the morning I brew. I always have very active fermentation by the next morning.