Cedar Rapids Brewing Society

I purchased some Go-Ferm for mead making awhile back and decided to give it a go with some Safale US05 dry yeast for my American Brown. I've never heard of anyone using it to rehydrate beer yeast, but it seemed likely to me that it would help and I wanted to see what would happen. I followed the instructions for rehydration as if I were using wine yeast and making a mead. After rehydrating for 30 minutes, I pitched, set my fermentation chamber at 64F and waited until the next morning. Everything seemed normal and then the fermentation began...

This thing has been out of control! I pitched at 62F. When the lag phase was over (around 18 hrs after pitching), the fermenter was up to 64F (i.e. ambient temps). Over the next 24 hrs it took off dramatically and rose to 74F! It's been holding steady since then, but is showing signs of having already burned through the primary fermentation (the bubbles-per-minute has noticeably decreased).

I'm used to the exothermic reactions in fermentation bumping up the temp by 3-4 degrees, but that typically requires several days. This thing went up 10 in one day. It could be a fluke and I'll be sure to experiment a bit more with this in the future, but this single case seems to indicate that Go-Ferm can effectively give beer yeast a bit more pep than simply rehydrating (or just pitching directly).

I've been curious about that, myself, but haven't done any experiments. Thanks for the data point.
-Tom

I tried using Go-Ferm again with another pack of US05 this past weekend. This time it was an IPA. Similar gravity (1.060 vs 1.068), similar volumes (5.75 vs 6.0 gallons), and identical pitching rates and temps (1 pack at 64F). I had the same lag time, but this time the IPA didn't exhibit the same out-of-control, violent fermentation that the Brown Ale gave me last weekend. This one has been more akin to what I normally see -- the fermenter only went up from 64F to 68F and it is still bubbling along after 3 days, rather than shooting up to 74F and burning through the entire primary in 1 day.

I'll keep running this experiment as I use dry yeast and fill everyone in if I ever figure out a trend.