I added oak to a Belgian Brut a few weeks ago. When I added the oak, fermentation was definitely over, and it was still and clear. I go to rack it off today, and it had a splotchy, sticky, slimy white film on the top. It sure looks like a pellicle, but maybe it’s not? I don’t know what else it would be.
I tasted the white film, and it didn’t taste like much, just kind of chalky and kind of tart. Do I have a Brett infection? It doesn’t look like my Berliner Weisses do, so I don’t think it’s Lacto.
Would adding more oak (and probably whatever bug it is) make it finish faster?
Gravity is 1.010 right now. If it’s Brett, how much lower should the gravity drop? I’m planning on bottling in champagne bottles, so I’m not super worried about bottle bombs, but I was really hoping to bottle it before May.
I didn’t take any pictures because I had a boil going and didn’t have time to go find my camera. I racked from under it. The tartness tasted more lactic than acetic, but maybe that’s just wishful thinking. If whatever it is forms again in the carboy I’ll post a pic then.
Beer is 8.5% ABV and about 30 IBUs. I thought Lacto was inhibited by IBUs that high, but maybe some strains aren’t? The ABV would rule out enterobacteria, right, so I probably won’t get sick from it? Could be acetobacter. I started the fermentation in two vessels, then combined when I oaked the first time. I may have gotten some O2 in there accidentally. I’m hoping it’s pedio or brett though, those would probably taste pretty good.
If it is some kinda bug I don’t want, is there any reason I shouldn’t use metabisulfite?
No it won’t make you sick, its just whether you like the flavor. I suppose you could sulfite, I haven’t heard of people doing this with beers though and it really doesn’t kill things just stuns them/sets the back. I’ve actually pasteurized beer in bottles before, that seemed to work well enough. Might be an option for you.
I don’t think it was a little air causing the infection, more likely it was something that drifted in on the wind or possibly on the oak cubes.
I don’t think you’ll be able to tell whats growing in there just from tasting the pellicle. But kudos for tasting a pellicle, thats nasty!
And as for FG, with Brett/lacto it can get down to 1.005 pretty easily but theres no telling if what you have is Brett. I think its more likely to be something like a mold or acetobacter. Even if it is a wild yeast, its not likely to give you a good result.
I don’t usually sanitize my oak chips, but I did briefly (60-90 sec) boil these chips before adding them. So I’m guessing whatever it was could live inside the oak itself, and not just on the surface.
I tasted it when I transferred, and it tasted pretty good. I think I’ll ride it out for now, and try sulfite if it’s getting too nasty for me. I was planning on carbing with wine yeast anyway, so I’ll get a sulfur-tolerant one just to be safe.
Probably not a good choice for oak, since the outside of those barrels saw cool slightly humid conditions for quite some time. I’d recommend oak chips or cubes like you buy for winemaking next time, douse them with JD if you want a little of that flavor.
One of the less crazy old-timers at HomeBrewTalk swears by them, so I thought I’d try them. I’ll probably toast them in the oven for a few hours to take care of any hitchhikers before I use them again. Or maybe I’ll just use them for smoking meat, like they’re made for.
I racked into a 5 gal carboy, and I had about a 3/4 gal left over I racked into a 1 gal jug. The “pellicle” or whatever it is came back in the 1 gal jug, but not in the carboy yet. Here are some pics:
Any idea what that junk is? I’ve been brewing for eight years now and never had an infection like this before.
That’s basically what it looked like when it was in the bucket before I racked. The gravity dropped from 1.010 to 1.006, so something is going on. PH didn’t drop appreciably, although I don’t totally trust my pH meter right now. The lower gravity has made the acidic sharpness a bit more apparent, but it doesn’t taste like malt vinegar yet. So far so good. My sulfite will arrive on Tuesday, so I’ll nuke it if necessary.
It’s actually tasting really good. I drank the hydrometer sample, and thought about going back for another. No noticeable DMS, but I’m not sure I’d recognize it unless it were pretty strong.
If it’s tasting good, I would just drink it all now, quickly. I love a good funky beer, but unless you feel like risking the batch it’s best to just drink it. Save the gallon jug and see how that part of it goes over time, if it is still good then you got lucky and you can use that jug to dose another beer intentionally.
Looks like mycoderma aceti to me, based on the little round islands. Tough to say though. I agree that you’ll want to drink this sooner rather than later, maybe leave the gallon as your experimental batch and report back.
I’m not much of a Bio guy, but I came across this on wiki: “Acetobacter can be easily distinguished in the laboratory by their growth of colonies on a medium containing about 7% ethanol, and enough calcium carbonate to render the medium partially opaque. When Acetobacter colonies form enough acetic acid from the ethanol, the calcium carbonate around the colonies dissolves, forming a very distinct clear zone.”
That experiment sounds easy enough to rig up at home. I’m thinking diluting vodka to 7%, adding some calcium carbonate, and I guess sugar? Any ideas how much of those I should add?
If the gravity is dropping, does that mean that the sugars are being consumed? Acid is denser than ethanol, right? So if the bug were eating ethanol and making acid, the gravity would go up? Do acetobacter eat sugar?
I don’t think you’d notice a change in gravity before things really got going. You’ll smell vinegar long before you can measure it. Just leave a little of your beer in a bottle with plenty of head space, in a couple of weeks it’ll smell like vinegar if this is acetobacter.
Tom can you tell the difference between Brett, mold and/or acetobacter from looking at its growth early on? I would assume they both start as colonies/mycoderma/“flowers”. I think the latter two are more commonly encountered than Brett.