How long is too long - yeast rehydration

[Pyrexic]

I typically use liquid yeast and starters, and see a fair bit of activity in 12-18 hrs after pitching. However, just brewed a recipe that strongly recommended using Fermentis US-05 dry yeast. I know I started the rehydration process too soon, but I just read that after 30 min to and hour, the yeast will start to die off without any sugar present. I had GoFerm in the water but was just that, water, not like my usual starter with wort. It was rehydrating for about 6.5 hours before it was pitched.

At the moment, there is no activity visible after about 30 hrs. Do I need to re-pitch?

 

[Kevin58]

Just pitch it directly into the wort. Also, if I'm not mistaken US-05 is of the Chico yeast strain. You can substitute virtually any other Chico yeast and get nearly identical results. Wyeast 1056 is the liquid yeast I use often as a substitute. White Labs WLP 001 is another good one and I used to use Imperial Yeast A07 all the time until both of my local homebrew shops stopped carrying Imperial.

As to why you are not seeing activity... what was your starting gravity, what was the wort temperature, and how many packets did you pitch?

Dry yeast is processed and packaged with a nutrient coating which is important for the yeast to have available when they wake up. For this reason I never rehydrate dry yeast (it will rehydrate in the wort!) and I never, ever make a starter with dry yeast. With that nutrient coating removed prior to pitching it is likely that the yeast could be stressed and trying to play catch up. You may very well see some activity around the 48 hour mark.

 

[Pyrexic]

Brewed a double IPA and OG was 1.079. Pitched at 70F.

Will have another packet tomorrow and if no activity by then I’ll pitch another pack directly. Also raised the temp a little from 68 to 73 to stimulate activity.

 

[Kevin58]

With that OG I would recommend pitching 2 packets of dry yeast.