Yeast Differences

So, I'm only on my 3rd brew, so I still consider myself more or less a newb.

Anywho, I'm seeing some singificantly different yeast behavior. This isn't really unexpected, since yeast are living things, etc.

For my past 2 brews, I used "Coopers Ale Yeast". It seemed to ferment very quickly (it fizzed/bubbled so much blew my airlock off the first time, second I used a blowoff tube). Now, I'm not convinced that this was due to the yeast, I may have let the fermentor get as hot as mid 70F. Which I know is a little on the hot side.

This time, I followed a recipe for a "House Amber" posted by Revvy which called, specifically, for Safale US-05 yeast. This time, I paid more attention to the fermentor temp, and it's been steadily bubbling now for over 24 hours (where as with the Cooper's it would have almost completely stopped bubbling by now). Overall, seems to be going at a slower pace, and my krausen looks better (only about an inch of it, instead of filling the carboy and blowing out the tube).

What I'm wondering is if the 2 yeast strains just act differently, or if my attention to the temperature is also affecting things. Probably a bit of both I'd guess. Or is US-05 known to be a slower fermenting yeast? I'm far more happy with the fermentation of the US-05 than the Coopers, so also wondering if Revvy is watching (and I'm sure he is, heh) if he could explain shy specifically this yeast strain? Does it impart a more nutty flavor?

Thanks fellas!

There are many variables that control yeast activity, but yes, temperature is probably the most critical variable. The higher the temperature (to a certain point), the faster the fermentation. If you let it get too high, though, you will observe a slowdown (and an undrinkable beer).

All things being equal (cell count, oxygen level, gravity, temperature), you'll observe very little variability in fermentation time from yeast to yeast.

US-05 is a very neutral ale yeast. So, if you want the hop and malt flavors to come through, use this yeast. Try to keep the temperature of the wort (not the ambient air) at ~65F for best results.

Copper's ale yeast is a somewhat neutral yeast that produces a distinct fruit character. I've made several summer ales with Coopers yeast with great success. Try to keep the temperature of the wort at ~70F for the best results.

Hope that helps...

Actually it does, and it explains some.

I've made 2 pale ales with Coopers, and noticed a barely detectable apple taste. For now, I have a cooler that I keep my fermentors in, and I fill it with water (to help stabalize the temp) and I have a thermometer in the water. I try to keep the water around 60F by dropping frozen water bottles in it when I can.

With my previous 2 brews, the water temp was around 70-75F which I would expect the wort to be a good bit warmer. The previous 2 brews were ok, not fantastic, so I have high hopes for this one.