Yes, absolutelyin the fridge.As far as fermentation I use a deep freezer with analog temp controller and keep the ambient in the range of 64-68 degrees usually. I never get a vigorous fermentation and mainly use US-05. I just increased the temp a tad in there to run 66-70 ambient after I added that 2nd pack. I have re-hydrated the yeast twice now and the first time the fermentation was very mild and this time non-existent. I think I am done with that extra step.