13 replies to this topic

[passlaku]

I have been using mtn's (or was it george's) method of rehydrating yeast by just dumping the packet into a new pint of bottled water. I usually just have it at room temp and let it sit for 15 min after I dump the yeast on the water. Then I shake it up and pour it in to the fermenter. I don't do anything special in trying to get the water temp up and so far my beers have come out fine. Just wondering what you guys thought about this process.

[MtnBrewer]

Wasn't me. I only use dry yeast for WM&C.

[Slainte]

I would follow the manufacturer's instructions. They probably know best.

[passlaku]

Fermintis' instructions for homebrewers are to simply sprinkle the yeast onto the top of the cooled wort. I am under the understanding that this process kills half of the viable dry yeast.

[Slainte]

Fermintis' instructions for homebrewers are to simply sprinkle the yeast onto the top of the cooled wort. I am under the understanding that this process kills half of the viable dry yeast.

I would follow their instructions for the commercial brewers.https://www.fermenti...Tips-Tricks.pdf

[Brian72]

Fermintis' instructions for homebrewers are to simply sprinkle the yeast onto the top of the cooled wort. I am under the understanding that this process kills half of the viable dry yeast.

When I "rehydrate" fermentis yeast, I'll pull about a 1/2 cup of wort about 30 minutes into my boil and let it cool and add 1/2 cup of cold water to that to help get it at room temp. Then I add my yeast to that and cover it with foil until I'm ready to pitch. For me it kinda does double duty, rehydrating and it wakes up the yeast and gets it going for when I pitch.

[MyaCullen]

I hope this isn't a hijack, but i have finally started using Go-Ferm in my WM&C re hydration. Does anyone beleive there would be a benefit to using it when re hydrating dry beer yeast? The Go ferm really seems to do the trick with wine yeast.

[MtnBrewer]

I hope this isn't a hijack, but i have finally started using Go-Ferm in my WM&C re hydration. Does anyone beleive there would be a benefit to using it when re hydrating dry beer yeast? The Go ferm really seems to do the trick with wine yeast.

I don't think it would hurt anything. It's very important for WM&C because the gravity is much higher and it's a shock to the system for the yeast to suddenly find themselves in that environment. My guess is that it's probably not necessary. It's one of those if it ain't broke don't fix it type of things. If your fermentations have been going the way you want them to, then I see no reason to change.

[strangebrewer]

I agree, if it ain't broke don't fix it. Rehydration is pretty traumatic to yeast but wort is an ideal medium for them to grow in so you may get a high mortality rate on rehydration but those who survive reproduce rapidly. When yeast rehydrate if there is no must or nutrient for them to pull in as they are rehydrating it will cause many yeast to die or become weakened. That is the point of products like GoFerm which provide just enough nutrients so they don't die off on rehydration. Adding just any nutrient is not the same as most nutrients in to high a level is toxic to yeast. For beer I say it's not such a big deal but in Wine and Mead musts which are not nearly as hospitable between their pH and lack of nutrients you do everything possible to give the yeast a leg up.

[ThroatwobblerMangrove]

I rehydrate in 90-95F water that has been boiled. At some point someone posted an article on this and that's what was recommended by the experts. The temperature is important for keeping the yeast as viable as possible.

[Pseudolus]

When I "rehydrate" fermentis yeast, I'll pull about a 1/2 cup of wort about 30 minutes into my boil and let it cool and add 1/2 cup of cold water to that to help get it at room temp. Then I add my yeast to that and cover it with foil until I'm ready to pitch. For me it kinda does double duty, rehydrating and it wakes up the yeast and gets it going for when I pitch.

My understanding is that the yeast, when dry, can't regulate the compounds that come across the cell membrane. So when you rehydrate in water you allow the membranes to come back "on line" in a safer environment. When you add dry yeast directly to wort those sugars can zip into the yeast cells, overwhelm it, and kill off a good portion. Sprinkling works okay, but, if you're going to bother to rehydrate, you're better off just using plain water.I use the microwave. I put a small amount of water into a clean glass jar (applesauce, tomato sauce - that kind of thing) and pop it into the microwave for about 2 minutes - just long enough for it to boil a little. (I figure this sanitizes anything nasty in there, even beyond having it really clean.) I let it cool slightly in the microwave (just so I don't scald myself) then take it out and put the (sanitized) lid on. I let that cool down and then I use that for my rehydration medium. I guess I'm essentially making my own bottled water.

[shmgeggie]

You could just loosen the cap and warm the pint of bottled water a bit to about 90-100 in the microwave.

[Salsgebom]

During rehydration the cell membranes undergo a transition from gel to 'liquid crystal phase'. To achieve the higher viability that rehydration is claimed to give you, it must be done at or above whats called the phase transition temperature. The dryer the membrane, the higher the transition temp. This also varies depending on membrane composition, which of course we don't know. The yeast manufacturers have decided 90-100*F is a good average to hit above the transition temp.So, it's important. This information was provided by Lallemand.

[ncbeerbrewer]

I have brewed with Dry yeast more frequently this year than in the past. I have used US-05 each time too. For the first time I followed Palmer's guide online to rehydrating and pitched once I cooled the water down to 80 degrees. Fermentation started in about 6-8 hours. The second time I decided to follow Safale instructions so I sprinkled onto the wort. Fermentation started in about 12-18 hours. I thought the rehydration worked better and I prefer that method. In both cases though fermentation was complete and acceptable as well.Going back to the OP: The only thing I would not feel comfy with is not santizing the water by at least raising the temperature appropriately but if you have had success with it then I say keep it going.