Hmmmmm....no RO water for rehydration?
Saturday I brewed using S-05 dry yeast. Put some RO water in a Pyrex cup, boiled it in microwave, covered with sanitized foil, waited until it cooled to room temp, added the dry yeast, let it sit for 30 minutes, stirred again (sanitized spoon), recovered, then pitched when the time was right (wort at about 76 degrees, yeast was at a similar temp).
It did take nearly 24 hours to get going at a set temp of 65 degrees (put in ferm chanber so it slowly cooled down to 65). But it's going.
I didn't recall the "don't use RO water to rehydrate" so I visited Fermentis' website to see their specific instructions for rehydration. Here they are:
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes. Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel. Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the wort using aeration or by wort addition.
No admonition to avoid RO water. That said, next time I'll probably rehydrate in my tap water just to see if there's any difference in lag time.