Mid-State Brew Crew

[rich]

Short answer: Yes, you should rehydrate.

Why? Yeast that has been dried out cannot control what substances it absorbs though it's cell wall. If you just dump the dry packet into your beer/wine/cider/mead the cell wall will absorb sugars, minerals and other chemicals, killing a lot of the little guys. The cell counts in most dry yeast packets are very high because the manufacturers know a goodly portion will be killed by dry pitching.

If you rehydrate the dry yeast in 90-105 degree sterile water the yeast cells can wake up. The cell walls become elastic again, and the yeast once more has control of it metbolism.

Wait...I'm confused. I thought the sugars vitamins and minerals in my wort were good for the yeast?

Answer: They are, but the yeast needs to metabolizes them naturally. Orange juice is good for humans, but if you were to intake it wrong, say, injecting it into your juggler vein, you'd likely have some problems.

Another weird analogy: I like to wake up and then eat breakfast. If I were to be awakened by someone cramming scrabbled eggs down my throat I'd be pissed off, maybe even choke and die!

In short rehydrate you dry yeast. They will thank you and produce the ethanol you want.
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