Souring a fermented batch of beer

I made a 5 gallon batch of American Pale Ale a few days ago and the fermentation is starting to wind down. I want to take 2.5 gallons of the beer and sour it with some yeast I harvested from a bottle of Odell Friek. Will this work? Will it continue to ferment out the remaining sugar or will this be a waste of perfectly good yeast?

How many ibu in your pale ale?

There is about 35.2 IBU’s in this batch. Its a bit too high for this type of yeast :frowning:

You could add some Brett L. Not familiar with the Friek or what it has in it

I just looked it up and it’s blended with a lambic so it might have some in it. it doesn’t mention bottle conditioning so it may not have the brett yeast in it.

That might be a bit too high to sour, but bottle dregs are usually more potent than lab cultures so I’d say it’s worth a shot. Not sure what’s in those bottle dregs, but if it’s wild fermented it probably has some pedio, which is much more hop tolerant than lacto. But it’ll take a looooong time. The biggest issue might be the bitterness, which usually clashes with sourness. But that’ll fade with time, too. I find a lot of jolly pumpkins to be too bitter for me when I buy them, but after 6 months or so it fades away and becomes awesome. If you can get JP in your area, those dregs will sour pretty much anything…

What about stepping up your dregs into a 1-gallon batch of unhopped wort to give the dregs a good head start, and then blending it all into your full batch? It should increase the bacteria count, plus dilute the IBUs a bit. Maybe toss in some maltodextrin for a long term food source for the brett and pedio.

Thank you all for your responses. I think I will try using this yeast in a gallon of the APA and see what happens. It may take a long time to sour but it will be a good experiment. I’m going to take Porkchops suggestion and get a few bottles of Jolly Pumpkin and step up the dregs for my next batch of beer. I’m just getting into brewing sour beers and I’m finding the possibilities are endless.

If you do go with JP dregs, no need to step up. I like to use a nice estery Belgian yeast for primary and then just direct pitch the dregs into secondary. Rack the beer into the secondary carboy, and when you get around to drinking a bottle, spray down the stopper and mouth of the bottle, and pour them straight into the carboy. By the time you get the stopper back in, it should be soured. Well maybe not that fast… but within a month or two it will probably be soured and ready to package.

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I wonder how your experiment turned out. It’s tough to sour after fermentation. I don’t really think of Brett on its own as being sour. Here’s an interesting article on hop tolerant non-sac strains of yeast.
https://www.themadfermentationist.com/2018/05/lactic-acid-yeast-hanseniaspora-and.html

Hey squeegeethree the experiment was put on hold. Too many other things came up but I plan to continue with this experiment in the future. Thanks for the interest.

Souring after primary fermentation is pretty standard

I didn’t think people sour with Lacto and Pedio after primary fermentation. I never have.

Pedio is almost always used after primary fermentation, hence the year-long (or longer) time period for making a traditional sour. Traditional lambic (or berlinerweisse, Flanders red, oud Bruin, etc…) is a good example, although you could argue that it’s all pitched at the same time. Regardless, the activity of lactic acid bacteria happens well after sacch is finished.

Ahh. Yes.
“When the main fermentation is complete and the Saccharomyces population
in suspension begins to decrease, the lactic acid bacteria start to
increase in population. If a prepared lambic culture was not used, this
is the time to add the lactic acid bacteria. It is important to note
that Lactic Acid Bacteria is very sensitive to even moderate levels of
IBU. Keep IBU levels below 10. The lactic acid cultures responsible
for souring a lambic beer are: Pediococcus and Lactobacillus (Wyeast
5733 and 5335 respectively). The temperature of the fermentation should
be allowed to rise to allow the lactic acid cultures to establish
themselves. The sourness will continue to increase for up to 2 years.”

Back to the OP, it doesn’t seem possible to use the Lacto with these IBUs but you could have just added lactic acid.

All depends on the lacto. Strains from commercial bottles tend to be pretty potent, and have built up some tolerance to hops. 30 IBU is pretty achievable with commercial dregs, but that obviously isn’t going to work for your typical lab cultures.