Berliner vomit: dump, or reinfect?

[C38368]

Apparently, I'm not the first one to do this, so, cool. I recently tried my hand at making a sour beer, at the request (?) of SWMBO. Because I still have fairly limited process control, and only had about five weeks to make it happen, I went with a Berliner weisse, instead of a more complex sour.

I opted for what (I think) is properly characterized as the no-boil kettle-souring method. But just in case, here's what I did:

1) Mash at whatever temp Beersmith told me to, for a period of time;
2) Draw off about 6 quarts of mash for a decoction, and then mash more;
3) Sparge into boil kettle;
4) Heat boil kettle to about 210°, then turn off the heat, cool to about 110°, and transfer to Starsan'd-up, glass, carboy, and pitch a lacto culture;
5) Let the carboy alone for about 24 hours, then pitch yeast (Wyeast 1007 German Ale out of a 1L starter);
6) Keg after about three weeks.

Now, what I ended up with is a very nicely pale, and extremely tart Berliner weisse, that absolutely reeks of vomit. Weird thing is, it doesn't taste at all like vomit, which I don't understand.

My understanding is that the rancid cheese/vomit smell/taste is the result of butyric acid, which is produced by a variety of aerobic microbes, up to and including C. botulinum, and is a common off-flavor in sours. I also understand that Brett is capable of converting butyric acid into something that tastes of pineapple and tropical fruit, if the levels are low enough, but that this conversion is inhibited by lactic acid.

So my question is: if I have a corny keg full of Berliner weisse that stinks of vomit, is it worth months of downtime on that keg to infect it with Brett and see if it gets better? Or is that just a waste of time? Even through C. botulinum is apparently fairly rare in a sour beer, it's still, you know, C. botulinum; should I be worried? Worth the risk?

Also, if anyone has any insight into how this happened, I'd love to know. I did not transfer into the carboy under CO2, but it was sanitized before the transfer, and my understanding of pasteurization is that, while everyone says to boil for like, 10 minutes, most microbes are dead and gone after about that much time at around 160°, and it's mostly spores and cysts that become a problem after that, no?

Anyway, thank you all! Anyone up for a sour?

 

[arnobg]

Sorry I can't help, but I'm subscribing because I'm researching to brew a Gose or Berliner Weisse for the first time and would like to avoid this.

 

[KeyWestBrewing]

How much headspace did you leave in the carboy? You didn't mention but my guess is you left too much head space and that created too much oxygen exposure. I can't comment on whether Brett will save it or not but if you want to get a handle for the process without investing a ton of time and money check this out...https://www.homebrewtalk.com/showthread.php?t=579458

 

[55x11]

When I make sours, I use sour mash or sour wort method where I keep the wort (or mash) at 110F or so for a few days to let lacto do it's souring. Ideally in oxygen free environment (purged with CO2 and covered with saran wrap in a mash tun, but perhaps easier done in a keg with a heater attached).

Occasionally I have subtle butyric acid smell which disappears after a brief boil that I do to kill lacto.

I suspect your sour may have been affected by Clostridium.

From http://byo.com/malt/item/889-how-to-make-a-sour-mash-techniques
"The most common contaminant of a sour mash is Clostridium butyricum. This anaerobic bacteria produces butyric acid, a foul-smelling compound that turns the mash rancid. Sour mashes infected with Clostridium should be thrown out. Luckily, these bugs are inactive above 112° F. Keeping the sour mash above this temperature will inhibit Clostridium."

 

[passedpawn]

Don't try to save it. Toss and make another.

I've made several berliners, but I went the safe route by adding the lacto at the beginning of fermentation. Even though I gave it several days head start before I added the sacc, it still didn't get sour (one batch I got into the 90's, hoping that would help, and even after years in the bottle, very little sour there).

Next time I'll sour in the kettle by boiling the wort, adding some dirty grains, leaving covered for a few days until it's at the right funkiness, then reboiling.

 

[secondbase]

Basically, if you can taste vomit the butyric is above the threshold for brett to turn it into pineapple. I would dump this batch. Next time around, limit the amount of oxygen exposure (no headspace or purge the headspace with co2) during the kettle sour process.

 

[Qhrumphf]

The butyric/isovaleric acid thing is typically from enteric bacteria and access to oxygen. If there was headspace in your carboy, the temp fell too far below 110F before the Lacto got to work, that's your problem. If the temp drops too much to keep the lacto happy, other bugs you don't want working can get a stronger foothold. I don't know for sure about C. botulinum in your off aromas, but I do know that for C. botulinum to be dangerous (the organism itself won't hurt you) it has to have the right conditions to produce to botulinum toxin. In this case, the oxygen access to produce the vomit aroma means an aerobic environment and thus no botulinum toxin.

Next time, purge it with CO2, and keep that temp around 110F until the lacto has done its thing. And you'll get better results if you drop the pH initially. Below pH 4.5 most of the enteric stuff (and C Botulinum as well) cannot survive (or at least can't grow), and results in a much cleaner sour.

 

[pricelessbrewing]

Like they said, it's butric acid.

My recommendation is to skip the sour mash approach, and go with sour worting using a pure lacto culture. If you have access to omega yeast labs, their lacto blend is awesome for this as it's pure, high cell counts, and contains L. Plantarum which sours quickly and works at room temp.

Alternative sources would be the yeast bays lacto blend (also contains L. Plantarum) but as it's propagate by white labs, it doesn't have the best cell counts. One more option is to put a few probiotics in a starter, and pitch the starter into the wort after a day or so. Should sour quickly.

 

[Calder]

Dump it. Sounds like it got contaminated.

1) Mash at whatever temp Beersmith told me to, for a period of time;
2) Draw off about 6 quarts of mash for a decoction, and then mash more;
3) Sparge into boil kettle;
4) Heat boil kettle to about 210°, then turn off the heat, cool to about 110°, and transfer to Starsan'd-up, glass, carboy, and pitch a lacto culture;
5) Let the carboy alone for about 24 hours, then pitch yeast (Wyeast 1007 German Ale out of a 1L starter);
6) Keg after about three weeks.

#4 - Cool quick and ensure no contamination gets in. Do not aerate. Need to keep temp up to get decent souring. Put airlock on fermenter.

#5 - Do not add yeast until the wort has soured, otherwise it could take a long time. It may take a week to sour. Pitch a lot of yeast (yeast cake works fine) due to low PH of soured wort. Aerate when pitching yeast.

#6 - Yes, you can keg at 3 weeks.

 

[Callacave]

Like they said, it's butric acid.

My recommendation is to skip the sour mash approach, and go with sour worting using a pure lacto culture. If you have access to omega yeast labs, their lacto blend is awesome for this as it's pure, high cell counts, and contains L. Plantarum which sours quickly and works at room temp.

This.

I cooled my wort down to 90 and added the Omega blend. Less than 48 hours it was almost a little too sour, but the beer still came out great for my first Berliner. You really can't go wrong with this blend.

 

[leesmith]

Ok...I've found the trub from the lacto/yeast combination to smell faintly like vomit (sounds so extreme). When I keg and put it in the fridge for carbonation and then a couple days later take a sample it's still smelling faintly of that BUT as I clear the keg dip tube of the trub that has settled the smell goes away.

I brew the MTF Gose. I make a Lacto starter with Swansons Plantarum probiotic capsules...pitch and maintain temp for 12-18 hours then pitch yeast. I don't kill the lacto as my wife and I like them real sour.

Does this happen to anyone else?