I recently got my hands on an adjustable relief valve, which is a very snazzy bit of gear.
Basically, you can use it to ferment beer in a keg, without having to worry about the pressure buildup: anything over 15 psi at the most is outgassed, and in fact you can set it to let out anything over 10 or 5 psi if you like. (Mine is attached to a pin lock quick disconnect, and the pressure gauge looks a little different, but it’s basically the same thing.)
For fermenting in a keg, this is a massive improvement over doing it with a plain old blowoff tube clamped onto a ghas outlet quick disconnect, with the other end shoved into in a bottle of sanitizer or vodka: there’s no risk of a kink in the hose and massive pressure buildup of the kind I got when I tried it. But having no experience with this bit of equipment, I didn’t really know what to expect.
However, I was in a big hurry to use it, because, without a spare fermenter available, I wanted to ferment a beer I’d made with my students using it. I had a cake of Kölsch yeast ready to go, after all, and had just received the adjustable relief valve a few days before. But I figured, what the hell, go for it.
The problem was, nothing seemed to happen inside the keg. When I checked it a couple of days later, I saw a little goop on the underside of the lid, but no krausen. What did not occur to me was that, sitting at room temperature but under 15psi, the beer could have fermented out completely in two days.
Which is what I discovered it had done, but only after racking a gallon of it out into a carboy. Was I smart? No, I was not smart. I could have simply taken a sample and tested the gravity, but that only occurred to me after a gallon was in a sanitized carboy.
So anyway, what can I say: the brew had fermented down quite radically, all the way down to 1.002. (Which is kinda too low for a Kolsch, but ah well.)
That means there’s just 3.5 gallons or so in the keg, but that’s not a big deal: at the last event involving beer, students didn’t partake too much anyway. But what to do with the (almost certainly somewhat oxygenated) Kolsch in the carboy? It seemed foolish to contemplate racking it back into the keg, so instead, I racked it into a couple of clean, sanitized wine jugs I had on hand, and added some souring cultures: into one, I added a Roselare blend, and into the other, some Brettanomyces B that was given to me a while back.
The Brett is almost certainly still viable, but the Roselare I’m not so sure. Probably that culture will have to be spiked with some other stuff, though that’s fine with me: I’ll use it to build up a culture for a month, that I can use to complexify some other sour cultures I’ve got going now.
In the meantime, I’ve got a couple of other interesting cultures I need to get brewing with, including a Brett L smack pack, some Lactobacillus delbrueki, and a Farmhouse Saison blend with unspecified Brett in it. All of those are things I need to get brewed now, if I am to enjoy the funkiness they impart before it’s time to pack up my gear and bid it farewell.
But the bottleneck is that I have several meads I’m bulk aging, which need to go into wine bottles. For that to happen, I’ll need to clear them, so I think next week is going to be the week of mead-clearing and mead-bottling, followed, at the end of the week, by a brew session that will end up putting beer into my carboys–glass–so that I can ferment with all-Brett (in the case of the Brett L.) and that Farmhouse Saison culture I mentioned.
In other news, my friend Soyoung is organizing a Yeokgok Brew session soon, and wants to invite myself, her assistant Jun Won, and another local brewer named Inho. We spent some time working out possible recipes the other day. The theme is spiced brews, and she’s planning a double batch… some to share in one place, and some to share in another. It looks like it’ll be a fun brewday…