Did anyone else see the article in BYO in Dec. 2011 on experimenting with dry yeast? They reported on experiments using rehydrated yeast and dry yeast directly pitched into the wort. The results seemed to indicate that no real difference in taste or attenuation was apparent. Therefore, is it worth rehydrating given the chance of contamination. I was curious what everyone else does and if you ever noticed a difference?
Jamil Z. and Chris White (Yeast) said that you kill about half your yeast when you dry pitch. The strains seem to be so consistent that you may get a similar result either way. I personally go through the hardship of rehydrating. I figure it's still cheaper and less work than making a starter for liquid yeast and I love to make things more complicated than they should be.
I personally do not have any concerns about contamination when I rehydrate my yeast. The rationale for rehydrating dry yeast is that you have more viable yeast cells for pitching into the wort. It has been reported that up to 50% of the dry yeast cells can die if you pitch them into the wort without rehydrating. It is entirely possible that even though a portion of the yeast cells die when you pitch then without rehydrating there is still enough yeast cells to get the job done. In other words there may be “no real difference in taste or attenuation was apparent.” I choose to rehydrate since it is an easy step to take and I prefer to have as many viable yeast cells as possible. It may be true that I would not notice any “real difference in taste or attenuation” but I rehydrate none the less. Cheers!
Some dry yeast brands say _not_ to re-hydrate. Others are silent. --- Like Momma used to say... "Do what you're told and there won't be any trouble."
I forgot to rehydrate once, and the beer still turned out well. They've all turned out well since then (us-05, bry-87, s-04, still too early to tell on the belle saison, but it took off like a rocket). Could they have been better with rehydrating? Perhaps. Am I trying to win awards or go pro? Nope.
Taking off early seemed to be one of the consistent results of the study. A lot of people reported that the sprinkled yeast batches took off the fastest and finished a day earlier....did it mean anything. Not really in the end but was interesting to note. I will probably continue to rehydrate but was curious what others are doing.
I have hardly any experience with dry yeast, but I just used Danstar Nottingham in my blonde ale. I followed the rehydration instructions, pitched it, and it took off like a rocket! Active fermentation started within 6 hours and churned away pretty vigorously for 2 days before activity started to subside. I'm pretty impressed with the performance. Based on what I've read about using dry yeast, I think I'll always rehydrate. It doesn't make any sense to risk stressing the yeast or wind up under-pitching due to killing off some of the little buggers, unless of course you are trying to under-pitch...
I split 10 gallons of California Common between BRY87 pitched dry and 2 tubes WLP810. The dry yeast started first. Also the dry yeast finished .002 lower.
problem with rehydrating is that you may also be seriously stressing and/or killing a large percentage of the yeast via temp shock or shear. When you dump yeast from a 90F slurry into wort @65F, the temp shear can end up killing even more than the osmotic pressure may have killed. If using re-hydration methods, you have to be extremely careful and monitor temps closely with a well calibrated thermometer.
I rarely use dry yeast, and normally rehydrate just... well because thats what we are told to do for better beer.. This past weekend, I had to use dry for my stout, since my stir plate was broken. 1.125 OG wort, and I tossed in 2 packets of US04. I was lazy and didn't rehydrate it. I tossed it in the funnel while I was draining my kettle and washed it all down while it splashed. Hit it with the O2, and called it done. 4 hours later I had krausen at 65* degrees.. Beer's krausen dropped a day ago, so it went solid for 5 days. Haven't checked the gravity, but did pull a taste sample after krausen dropped to see how the roast and bittering was on it and was extremely pleased.
I used dry yeast (US-05) for the first time a couple weeks ago. I rehydrated and pitched while the wort was still warm (~77) and it took off. And kept going hard for probably four days - to the point that I was concerned about infection. Fortunately a taste test indicated otherwise. It's now down to 1.012. I'll be testing another sample tonight and again on Saturday before beginning the 7-day dry hop. I understand that when n=1, a result isn't really a result, but indications are good.
Telejunkie brought up the topic that you need to ensure that the rehydrated yeast is near the temperature of the wort that you are pitching it into. This step is called attemperation: “Adjust temperature of solution to that of the wort in 10°C (18°F) steps, by adding small amounts of wort at 5 minutes intervals and mixing gently (ATTEMPERATION)” Above is from:http://www.danstaryeast.com/library/rehydration-and-usage-tips-ale-yeast Cheers!
I routinely pitch dry and love the beers. I've rehydrated and have loved the beers. In terms of the final product (the only thing that counts), you might as well debate whether it's better to butter your toast horizontally or vertically. I'll do whichever is easier.
I have often wondered about that but never took the time to see if it was a valid concern. Thanks for posting this.
Here's another good link supporting rehydration and the proper way to do it: http://www.northernbrewer.com/connect/2010/06/the-importance-of-being-hydrated/
