I was surprised when I got 79% apparent attenuation on my most recent batch (English Pale) with WLP002 yeast. The beer was mashed at 150F. It was pretty cold out on that brew day (mash tun was cold from being stored in garage) and the mash temp settled a couple of degrees lower than planned, but, I figured 150F was fine and therefore left it alone rather than trying to increase the temp.
For what it’s worth, the beer is off the hook good, so, all’s well that ends well.
We’re you thinking that this was too high? Because it sounds right to me. I almost always hit the upper 70’s for attenuation with that strain.
Yes. I was expecting lower based off the specs for the yeast. White labs says to expect 63-70%.
That was the 3rd generation of using that yeast. The batch before did get 72% AA with 152.6F mash temp. So, I guess 79% isn’t too surprising given the lower mash temp and a different base malt (Muntons extra pale Maris Otter vs Briess Pale malt, maybe more fermentable).
I recently went from 1.050 to 1.009 with Munton’s which is way higher than you’d think it could manage.
Yeast specs make much less difference than wort fermentability. Using the same yeast I can get anywhere from 65-85% attenuation depending on the wort.
I am learning. Like I said the beer is great.
If I wanted to lower the attenuation to be closer to style should I raise the mash temp, change the base malt or something else?
You could try both, but I wouldn’t do it at the same time. A good start is to mash 3 or 4 degrees warmer and see where you finish. And of course there’s the option to use more specialty malts which generally raise FG. But if you like the overall flavor of the beer and don’t want to mess with your grist %, incrementally raising mash temp and keeping good notes is the best option.
Edit - Finding a less attenuative strain is another option too (obviously).
I am more likely to try a different malt or yeast than brew the same thing twice. I am planning an English Pale malt next.