I'm not seeing any bubbles or foam after rehydrating and proofing some US-05. Could it be a bad packet?
What is your procedure for rehydrating? Temps, etc... I use the 05 exclusively and have not had any troubles recently. Do you have the lot number and date code as well?
I let it sit for 15m in about 95 degree water and then added a teaspoon of sugar in room temperature water that I boiled in half the water earlier. I think I have a total of about 1 cup of liquid.
Re-hydrate the dry yeast into yeast cream in a stirred vessel prior to pitching. Sprinkle the dry yeast in 10 times its own weight of sterile water or wort at 27C ± 3C (80F ± 6F). Once the expected weight of dry yeast is reconstituted into cream by this method (this takes about 15 to 30 minutes), maintain a gentle stirring for another 30 minutes. Then pitch the resultant cream into the fermentation vessel.
Alternatively, pitch dry yeast directly in the fermentation vessel providing the temperature of the wort is above 20C (68F). 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 and then mix the wort e.g. using aeration.
yeah, don't do that. just re hydrate and pitch.
... or just pitch. The beer will start in a reasonable amount of time (active ferment in 6-8 hours typically) anyway and will finish the same. I have used dried yeast at home and commercially and have seen no proof that rehydrating makes a notable difference in the finished beer. Between the extra steps and added risk of contamination (small though they be) I would rather keep it simple; pitch and done.
FWIW, in a commercial vessel I dump the dry yeast in through the manway before xfering the aerated wort into the ferm. AT home, I dump it into the bottom of my fermenting bucket shortly before I pour the wort in.
The bottom of my carboy is wet with starsan so would feel pretty uncomfortable re-hydrating the dry yeast in starsan residue before adding the wort. Probably doesn't matter, but I always pour the yeast on top of the wort, not the other way around.
I do re-hydrate but never felt it really made much difference and am glad to see a professional feels the same way.
I follow you with the puddle of star san thing... I use iodophor and tip my bucket a few times to make sure it is pretty well all drained out. Even if there is a wee bit left it is on the outside where the level is lower, I dump the yeast in the center and it stays dry. Sprinkling on top is fine, it works... all else being equal though, I do like to pour onto it (or in the case of a unitank, pump into it) because it gives an instant mixing. Not a major deal, of course.
You will find that probably half or more of commercial breweries that use dry yeast don't bother with rehydrating.
Yeah, that discussion was linked to in another thread, but here's the actual discussion:
http://koehlerbeer.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/
I'm finishing a rye stout right now and have a packet of US 05 on the counter. I might rehydrate, but probably not.
someone here stated that by pitching directly into the wort, about half the yeast dies because of osmotic pressure - cell walls have not all had a chance to reconstitute themselves before the sugar comes rushing in. i seem to remember this was from a reputable source, but can't recollect who... so might be hard scientific fact, or a repeated wives' tale.
Here's a probrewer.com discussion on the topic... you'll see they are pretty well split on who does/doesn't
http://probrewer.com/vbulletin/showthread.php?t=21350&highlight=rehydrate+dry+yeast
For me, I don't because a) it adds a step and I am about KISS and b) it is one more potential source for contamination.
whatever... make beer... be happy...
In the end the ONLY thing that matters is what hits the glass!
Really great link, thanks! It's nice to see that home brewers aren't the only brewers debating this. I'm guessing that it'll never be settled. Those of us who hydrate will, and those who don't won't. We'll all make beer, many of us'll make great beer, and I betcha most of us wouldn't be able to tell the difference between which of those beers used rehydrated dry and which used dry pitched yeast.
Enter your email address to join: