Been doing this for years as many of you know and just had a strange stop in fermentation.
I was using up some left over malt on hand. Had a still sealed sack of Breiss 2 row and 15lb of Pilsner both in a plastic bin. Used all the Pils and 40lb of the 2 row for 20 gallons bought 3lb Black malt to make a Porter. For yeast I had slurry Wyeast 1728 Scottish ale, made a gallon starter with that and pitched half in a 12 gallon conical, 1/4 into a 6.5 carboy and 1/4 into a bucket. Wort temp a little high in the 60’s, used an aquarium pump to aerate. The yeast had just very successfully fermented out 20 gallons of Scottish ale.
After one day it obviously had started fermenting by looking at the bubblers and Kreuzen on top. Next day nothing. OG 1.072 stopped at 1.052. Had passed the iodine test BTW and sticky sweet so conversion worked.
So today I’m off to find some dry yeast like US-05 to try to restart it. Can’t figure what went wrong?
You’re not measuring your gravity with a refractometer, are you? :mrgreen:
ducks
[quote=“porkchop”]You’re not measuring your gravity with a refractometer, are you? :mrgreen:
ducks[/quote]
Ha, no refractometer for me. I’m old school hydrometer.
I’d be surprised if it was the refractometer issue; if it really did finish, even with an uncorrected refractometer reading it should have measured lower than that.
But it’s incredibly hard for a beer that big to finish in one day, unless you pitch a truly massive amount of yeast, which you didn’t. In fact, I think a 1 gallon starter for 20 gallons of strong beer is a fairly significant underpitch.
How strong was the Scottish ale you harvested the yeast from? The cells may have simply been worn out. If they didn’t get enough O2 prior to fermenting the last beer, they might have quit on you. That happened to me once; it seems that the yeast can still manage to ferment well when you under aerate, but if you harvest after that they will be very weak performers thereafter.
I know, I was just messin’ with him. :lol:
[quote=“rebuiltcellars”]I’d be surprised if it was the refractometer issue; if it really did finish, even with an uncorrected refractometer reading it should have measured lower than that.
But it’s incredibly hard for a beer that big to finish in one day, unless you pitch a truly massive amount of yeast, which you didn’t. In fact, I think a 1 gallon starter for 20 gallons of strong beer is a fairly significant underpitch.
How strong was the Scottish ale you harvested the yeast from? The cells may have simply been worn out. If they didn’t get enough O2 prior to fermenting the last beer, they might have quit on you. That happened to me once; it seems that the yeast can still manage to ferment well when you under aerate, but if you harvest after that they will be very weak performers thereafter.[/quote]
The Scottish ale was a 1.082, a big one. I used the same size starter for it and it finished no problem. I run the aquarium for a while every batch an in the case of the conical the wort gets splashed in pretty good. All three fermentors quit at the same time. Never had a problem with an active quart to five gallon ratio before. I do not think the gravity reading is the problem and don’t have a refractometer.
This afternoon I will get some dry yeast and we will see tomorrow what is happening, I hope.
The US-05 will let you know what is going on, hopefully. I had similar thing happen on a 1.135 beer that stopped at 1.085 and it took me another month and lots of work to get it to finish at 1.050. Five years later and the beer is still cloying sweet.
My usual LHBS is closed on Monday so I went to another one not so close by only to find they had just one US-05 so instead it is going to be US-04. Not exactly the yeast profile I was looking for but close enough. Fingers crossed I will report back tomorrow.
Definitely fermentation activity this morning so perhaps all is not lost. All three airlocks are popping so I will measure the gravity again in a few days.
What was your mash temp? Did your temp get unusually high?
