Fermentis Rehydration Temperature

jayfaustini · 11-06-2011, 04:14 PM

Why does Fermentis recommend such low rehydration temperatures for their dry yeasts?

Everything I've ever read says 95-105 is optimal. But Fermentis' spec sheets recommend MUCH lower temps, generally 27C ± 3C (80F ± 6F) for ale yeasts and 23C ± 3C (73F ± 6F) for lager yeast.

I understand that every yeast has a different optimal rehydration temp, but 20 degrees lower seems strange.

Temperature shock of 20-30 degrees is probably worse for viability than non-optimal rehydration temperature.

Is this just a dubbed down recommendation to keep it simple and still prevent temp shock? Are they just recommending non optimal lower temps for people who don't step down the yeast temp to fermentation temps with small additions of cold wart?

theredben · 11-06-2011, 05:31 PM

Have you contacted them about it? That would be the first place to start. Here on HBT you will just get a bunch of contradicting opinions.

**samc** · 11-06-2011, 06:25 PM

Just a guess, but I assume it is the medium that the yeast is dried with that needs a lesser temp to penetrate and breakdown. Thin shell vs. thick shell.

I could of course be totally off base, but I like the way it sounds.

ChillWill · 11-06-2011, 08:13 PM

Ppppffftttt, I just do it around 30c (86f), or 35c (95f) for Nottingham.

I don't think the yeast is that fussy, just as long as it's there or there abouts my fermentation seems to take off smoothly and quickly with that technique (better than straight dry pitch, especially with notty which lags for me when pitching dry and it can be a bit dirty if you're not kind to it so I like to try my best, S04 is a bit more forgiving).