Monkeyspear
New Member
See what you make of this, because I can't figure it out. I brewed a stout using some opened bags of grains and hops that I wanted to get rid of before I move house (recipe below). The OG was .050. The fermentation started off okay, fairly vigorous. After four days, the airlock activity stopped but I wasn't worried, and left it for another four days at which point I took another reading; the SG was .040. I roused the yeast, and left it for another week - no change in SG. So I made a yeast starter using Wyeast 1056 and dumped in a few days later. A little more activity and then nothing. The SG was still .040.
I guessed I'd made a mistake with the strike temp and gone in way hotter than I thought; both my thermometers seem to be accurate, so I must have misread the one I was using to measure my strike water. To verify, I did an iodine test using diluted wort and it went black immediately, which suggests unfermentable sugars, right? However, I've since reboiled my wort (to kill off any chance of infection), cooled and added a shot of glucoamylase 400, then repitched with a Young's ale yeast. It's been 24 hours and there is no activity and the iodine test still shows signs of starches. pH is 4.1. What's going on? Do the malts I've used possess some unholy, unfermentables that not even glucoamylase can break down, or is there something else at work?
Recipe:
3 kg Weyermann's Chocolate Wheat Malt
1 kg Pale chocolate malt
1 kg Simpsons aromatic malt
28g miscellaneous mixed frozen hops, 12 grams at boiling (60 mins), 12 at 15 mins, the remainder at flameout).
Wyeast 1056 smack pack, made into a starter 48 hours before.
I guessed I'd made a mistake with the strike temp and gone in way hotter than I thought; both my thermometers seem to be accurate, so I must have misread the one I was using to measure my strike water. To verify, I did an iodine test using diluted wort and it went black immediately, which suggests unfermentable sugars, right? However, I've since reboiled my wort (to kill off any chance of infection), cooled and added a shot of glucoamylase 400, then repitched with a Young's ale yeast. It's been 24 hours and there is no activity and the iodine test still shows signs of starches. pH is 4.1. What's going on? Do the malts I've used possess some unholy, unfermentables that not even glucoamylase can break down, or is there something else at work?
Recipe:
3 kg Weyermann's Chocolate Wheat Malt
1 kg Pale chocolate malt
1 kg Simpsons aromatic malt
28g miscellaneous mixed frozen hops, 12 grams at boiling (60 mins), 12 at 15 mins, the remainder at flameout).
Wyeast 1056 smack pack, made into a starter 48 hours before.
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