I chose the Big Brew day to jump into my first batch ever of APA. Kept Safale US-05 dry yeast at room temp for a week and half and did not re-hydrate it before pitching into wort at 70°. Moved fermentation bucket into 1st floor closet which has been at a 68° temp since May 2nd. After 44 hours I noticed a good bubbling in the airlock every minute or so, and then it stopped the next morning. I've not seen any good bubbling since Saturday. (3 1/2 days now).
Should I have seen activity again by now?
Should I try wrapping a towel around the bucket to bring the temp up?
Am I just impatient?
Thanks
Gonzo
For your first brew, that is just fine. There are other ways to help encourage yeast growth, but you shouldn't worry about that until you've got a few more brews under your belt, and more money to spend.
but
For your next brew check out this Yeast pitch rate calculator
https://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/Chances are, you probably could have used 2 packs of US-05. Most of the time, 1 pack will get you there. My thought is that it's very easy to under pitch yeast, but hard to over pitch. Yeast does all the work, so I try to do whatever I can to encourage yeast growth.
Rehydrating yeast for beer isn't critical. Many of the dry packs have nutrients that you'd want to put into the wort and not rehydrate it.
Down the road, if you continue to brew you'd want to look at getting a stir plate with a 2 liter flask. Any good homebrew store will sell out of date yeast packs at a discount, or maybe give them for free. You can easily grow it back up with a stir plate.
Other ways to improve fermentation is aerating wort before pitching. As part of the boiling process, oxygen is removed from the water. Oxygen is important for yeast growth - but if you add O2 after the growth phase, you'll get off flavors. The cheapest way is to shake your carboy a lot to reintroduce air, which is ok to do. The next cheapest way is to rig up an aquarium pump with a diffusion stone to inject air back into the wort. Most expensive but best way is to use an oxygenating wand with pure O2. If you'd like to learn more, let me know and i can find some links for you.