I brewed 5.5G of a big 1.098 oatmeal stout Friday morning with a 1L 1.038 starter using two tubes of WLP007 per Mr. Malty. After about 18 hrs of pitching I had a nice 1" layer of krausen. Fast forward to this morning and the rubber stopper and blow-off tube I had going to a 1G milk jug of star-san were on the floor, and krausen was everywhere. No big deal, I’ve had krausen explosions before and it still hadn’t fallen so I’m not too worried about oxidation, but… the neck of the carboy cracked on the inside!
The yeast are going so crazy that the beer inside the carboy looks like it’s on a stir-plate. I pitched a bit on the cool side for this yeast @ 68, so that shouldn’t be the issue. I’ve never seen anything like this. I think I really like it, but I’d love some feedback. I’ve never recycled yeast before either, but I think after this batch.
First off, pitching at 68 is good. However, what is your temp control set up? if none this was likely cooking at around 75.
Second, do I understand correctly that you had a stopper in the gallon jug that the blow off tube was leading to? or am I misunderstanding? If so then you created a sealed pressure environment and cracked the carboy that way. Still kind of impressive that those rubber stoppers can hold more pressure than a quarter inch of glass. If I am misunderstanding then I would guess the tube got clogged somewhere along the line and that cause the pressure build up which blew the hose out when it blew the stopper out of the carboy.
I always use a swamp cooler (my wife keeps our place similar to a nursing home) and rotate 1L frozen water bottles every 12hrs for the first few days, then every 24hrs after that. But yes, the temps inside probably hit 75, I’ll never know for sure though given the gear I have.
I just wrapped foil around the tube that goes into the jug, I didn’t have a second rubber stopper there, so all pressure should have been relieved via bubbles… which I timed to still be about 91 beats per minute last night after reattaching everything. Going forward I may just move my kid’s baby monitor to the closet to get the real answer as to how fast things took off and, like you said, to see what/where things got jammed up.
Yeah, in that case I would guess that gunk got up in the tube opening in the carboy and pressure built up there. I know when I get a clogged airlock in a bucket I can see the lid start to dome and when I pull the stopper it goes POP!! you can get an amazing amount of pressure build up using krausen as a sealing agent.
So after 9 days in the primary and no activity for a few days now, I transferred to the secondary. I measured 1.055 down from 1.098. Does that seem a bit high given the explosion and potential lost yeast? I don’t plan on bottling for another 4 weeks, so hopefully it’ll drop enough where no funky flavors decide to show up.
I think you should pitch more yeast. I would not have transfered it yet. You still have yeast in the beer but alot of them got left behind in the primary. The ones that are still in the beer are going to get really stressed out trying to finish up those 55 points. Just one opinion.
I figured that was the case. When I transferred it there was less than 1/2" compared to day 3 when there appeared to be about 2" of yeast cake, and that was even after the explosion, but I suppose you’re correct.
Logistics are actually the biggest issue because I did this 45 mins away at my parents house (fam is moving soon and the wife thought it best not to have this around) and we’re going on a cruise this weekend for our anniversary. It looks like I’ll pitch some more yeast once I get back, which will be about 3 wks from brew day.