You’re supposed to rehydrate dry yeast at around 100f. Doesn’t that get quite a shock when added to 65f wort? Doesn’t that increase lag time while the yeast adjusts to the much lower temperature.?
I normally just chuck the yeast in and that works fine for me, but I have a couple of bigger beers (1.080-90) planned and thought it would be a good idea to rehydrate for these beers.
I’ve heard a wine kit rep argue that the loss of yeast to temperature sheer is so great that they recommend not rehydrating dried yeast at all. I think that’s a bit extreme and really assuming that most homebrewers/winemakers can’t follow good yeast handling practices. I’d think your best results would be from rehydrating with a rehydration nutrient like Go-Ferm and letting it cool to your wort temp before pitching. With such a small volume, it shouldn’t take that long to cool.
That makes sense. It’ll be three gallons so one pack should do the job, I just thought it might be a good idea to give the yeast a bit of a head start.
Dan Listermann discovered the same issue with the customers at his store many years ago…15 at least. So many people were having bad experiences after rehydrating that he started recommending they don’t do it. Apparently that produced much better results.
I’m surprised to hear a recommendation to rehydrate at 100F. While I do boil my rehydration water to help sanitize it, I do let it cool to room-temperature before adding the dry yeast.
I’ve done unscientific trials on hydrating and not hydrating and have come to the conclusion that I get significantly better performance when I hydrate the yeast. I can understand that you could easily screw up the rehydration process by not properly working with the water, but I still think that we are better off with rehydration. The reduced osmotic stress placed on the yeast due to rehydrating with plain water just makes sense to me. Sugar-filled wort places more osmotic stress on the yeast, and I can imagine, does reduce the overall viability and numbers for the yeast pitch.
The thing that could easily catch many, is for the water temperature to be too hot and the cells being killed on contact. Without a thermometer, it could be difficult to say the water was cool enough if you aiming for 100 or 105F. You just know its warmer than body temperature. However with certainty, I can tell when water is colder than body temperature. It just seems like an appropriate safety precaution.
I had not seen Sean’s work on this subject. Just what I expect from the orange-hatted one. That work points to exactly what I contend, plain cool water is a better method.
He started out by selling home brew equipment he had engineered and manufactured. He has quite the reputation in the home brew world. And we get to buy from him regularly and drink his Chickow! !!!
Anyone who is been brewing for a long time knows Dan. The home brewing community used to be lot smaller than it is today. I used one of Dan’s false bottoms for years.
To be fair the yeast book says the most common range is 95-105, and that you should find out from the manufacturer what temperature is ideal. They also say warmth is critical to cell membrane health and that colder temperature will cause more of the cell to leach out. Who cares if the cell is alive if it is too weak and fragile to be of any use. Vitality can be more important than viability.
IIRC Fermentis recommends 80 +/- 6 for s-04 and us-05