I recently brewed a Bourbon County clone recipe modified from:
https://homebrewsupply.com/content/HBS All Grain Recipes/AG_INS_BourbonCountyStoutClone.pdf
With my current set up, I can only handle an 8-gallon mash, so I used about 18 lbs of grain, 1 lb of table sugar, and 8 lbs of liquid extract. My boil off was much lower than expected and I ended up with an OG of 1.113. Brewfather tells me I should hit an FG of 1.026 @ 75% attenuation.
I stepped up a 4 liter starter of WLP001 over the course of several days. I cold crashed it overnight and decanted it and pitched the thick yeast slurry. I did not use pure oxygen for aeration, but I poured the wort back and forth between 2 buckets like 7 times and shook the hell out of it. I also added 2.5 teaspoons of WLP yeast nutrient to the boil.
Fermentation was roaring, and after 10 days I took a SG reading, which was 1.034. Way high, with only 68% attenuation (sitting at about 10.5% abv). I was not happy about that, but I had saved some harvested WLP001 in case this happened. I then made a 2 liter starter with the harvested yeast and let it go 48 hours. I then cold crashed it overnight. The resulting yeast cake was huge. I decanted the liquid and pitched the thick yeast slurry into the wort. 48 hours later and no airlock activity. I checked SG, still at 1.034. I stirred up all the yeast cake and increased the temperature but I'm not expecting anything to happen. I haven't done a forced fermentation test yet. I did also read after the fact that I should have pitched the full 2 liter starter at high krausen instead of chilling and decanting.
I've hit my expected FG on every all-grain beer I've done. However, on two imperial stouts where I've had to supplement with extract I've ended up with 68% and 70% attenuation. Having just pitched an enormous amount of yeast into the wort and not dropping a single gravity point, I'm wondering if the wort is just unfermentable at this point, and if its due to the extract?
Thanks anyone for your insight!
https://homebrewsupply.com/content/HBS All Grain Recipes/AG_INS_BourbonCountyStoutClone.pdf
With my current set up, I can only handle an 8-gallon mash, so I used about 18 lbs of grain, 1 lb of table sugar, and 8 lbs of liquid extract. My boil off was much lower than expected and I ended up with an OG of 1.113. Brewfather tells me I should hit an FG of 1.026 @ 75% attenuation.
I stepped up a 4 liter starter of WLP001 over the course of several days. I cold crashed it overnight and decanted it and pitched the thick yeast slurry. I did not use pure oxygen for aeration, but I poured the wort back and forth between 2 buckets like 7 times and shook the hell out of it. I also added 2.5 teaspoons of WLP yeast nutrient to the boil.
Fermentation was roaring, and after 10 days I took a SG reading, which was 1.034. Way high, with only 68% attenuation (sitting at about 10.5% abv). I was not happy about that, but I had saved some harvested WLP001 in case this happened. I then made a 2 liter starter with the harvested yeast and let it go 48 hours. I then cold crashed it overnight. The resulting yeast cake was huge. I decanted the liquid and pitched the thick yeast slurry into the wort. 48 hours later and no airlock activity. I checked SG, still at 1.034. I stirred up all the yeast cake and increased the temperature but I'm not expecting anything to happen. I haven't done a forced fermentation test yet. I did also read after the fact that I should have pitched the full 2 liter starter at high krausen instead of chilling and decanting.
I've hit my expected FG on every all-grain beer I've done. However, on two imperial stouts where I've had to supplement with extract I've ended up with 68% and 70% attenuation. Having just pitched an enormous amount of yeast into the wort and not dropping a single gravity point, I'm wondering if the wort is just unfermentable at this point, and if its due to the extract?
Thanks anyone for your insight!