Due to being busy, I decided to mash in the evening and then sparge/boil the next day. Since I was brewing an Oud Bruin, I figured that if I ended up with a spontaneous sour mash I would still be OK. But what I got was a vomit-smelling mash. After a week and a half of fermentation, the beer still smells of vomit. What should I do? Will this odor dissipate naturally? Theoretically the butyric acid could react with ethanol to form ethyl butyrate which smells like pineapple. Should I pitch some Brett in addition to the lacto? I was intending to split the batch to make a pseudo-kriek/Oud Bruin for this summer and a proper Oud Bruin for next year.
I’d pitch it. I’ve read that the butyric will react but I don’t know that it will be complete and I don’t think its worth the effort and carboy space to find out it is bad in a year. PLus I think high levels of butyryl acetate might give you a fusel-type hangover. Brew another batch and don’t let it sour this time. From what I’ve read, souring a mash naturally is a hit-or-miss proposition. I did it once and it was OK although not very sour.
The taste threshold for butyric acid is really low. Even if some is reduced during aging, it’s still going to be nasty. A friend made a Berliner Weiss that went very wrong… the vomit flavor didn’t go away. Awful!
Chad Yakobson was just on the Brewing Network. He claimed to have a brew full of Butyric Acid and Brett ate it up and produced pleasant flavors. I think he said it took 6 months.
Some strains of Clostridium apparently do make butyric acid and are cheese spoilers according to my Google search. After sparging everything got a real good boil so I’m not concerned about there being active Clostridium in the beer.
I’m planning to taste and spit the beer out at a homebrew meeting. Any thoughts about the safety of tasting this beer setting aside the smell?
Personally, I wouldn’t risk it. Humans have a much larger capacity for ingesting toxins than most animals, so you probably won’t get sick, but man, I hate vomit.
I know the original poster is trying to figure out what went wrong so it doesn’t happen again. I get that. Totally understand. That being said… Maybe it’s just me, but I would NEVER tell anyone my homebrew smells like vomit!
Here is a synopsis of what Chad at Crooked Stave said at 1:51 in the show. Chad made a no boil beer which he spontaneously soured. The result has a lot of butyric acid (he didn’t say anthing about vomit but indicated that people didn’t like it). He then did a 100% Brett primary fermentation, blended it and aged it for 9 months.
But, was the beer in the end better than if it had never smelled like vomit in the first place?
I find it strange that people have so many issues with spontaneous souring. I’ve brewed a half dozen or so sour beers using grains for souring, and never had any issues like that, knock on plastic.
A brief update. Last week I added a Brett-infected oak spiral (clausenii) to the vomit beer. Yesterday I racked to secondary. There was definitely a pleasant pineapple on the nose but there is still plenty of vomit odor in general. Anyway I’m hopeful that a long secondary will eat up the vomit. I did not notice any Brett-induced barnyard characteristics.
