The last couple of beers I did have stopped fermenting sooner than expected. One was an Irish Red that went from 1.051 to 1.016. The other was an Oktoberfast ale that went from 1.058 to 1.020. They taste great so that's not really an issue, but I am curious why they stopped short of where I thought they would.
I mashed the Irish Red at 149F for 90 minutes. I also raised the temperature to 170 for the last 10 minutes (I BIAB). I fermented with a washed Wyeast Irish Ale yeast.
I mashed the Oktoberfest at 156F for 90 minutes and raised the temperature to 170 for 10 minutes on that also. I used S-04.
I also did Yooper's Pale Ale a couple of months ago and it stopped at 1.020. It was fantastic still, but I didn't know why. I don't remember what I mashed at, I didn't take as detailed notes back then. It would have been in the area of 154 though. I fermented with S-05.
I've read that higher mash temps = a less fermentable wort and will leave sugars behind that can't be fermented. I assume this is the reason for the Oktoberfest stopping where it did. That doesn't explain why the Irish Red stopped early though, unless the 10 minutes at 170 was enough to leave a lot of unfermentable sugars in the wort? I don't know if that's possible, the science of it still confuses me. Or maybe it's simply that the washed yeast couldn't do anymore.
Anyway, should I try keeping my mash temp lower? Should I get rid of my little mashout? I always thought that it helped with my effiency, but if it's affecting the FG then maybe I need to stop. Thanks
I mashed the Irish Red at 149F for 90 minutes. I also raised the temperature to 170 for the last 10 minutes (I BIAB). I fermented with a washed Wyeast Irish Ale yeast.
I mashed the Oktoberfest at 156F for 90 minutes and raised the temperature to 170 for 10 minutes on that also. I used S-04.
I also did Yooper's Pale Ale a couple of months ago and it stopped at 1.020. It was fantastic still, but I didn't know why. I don't remember what I mashed at, I didn't take as detailed notes back then. It would have been in the area of 154 though. I fermented with S-05.
I've read that higher mash temps = a less fermentable wort and will leave sugars behind that can't be fermented. I assume this is the reason for the Oktoberfest stopping where it did. That doesn't explain why the Irish Red stopped early though, unless the 10 minutes at 170 was enough to leave a lot of unfermentable sugars in the wort? I don't know if that's possible, the science of it still confuses me. Or maybe it's simply that the washed yeast couldn't do anymore.
Anyway, should I try keeping my mash temp lower? Should I get rid of my little mashout? I always thought that it helped with my effiency, but if it's affecting the FG then maybe I need to stop. Thanks