Souring with WLP672

[biglakebrewing]

I brewed a low alcohol (~4%) wheat beer using aged EKG hops. The IBUs were calculated around 20. The beer was fermented at 68F using WLP007 for two weeks, and finished around 1.010. 53 gallons of this beer was added to a used oak barrel on top of ~20#s wild black raspberries. The beer was racked into the barrel before being crashed to carbing temps, so there would have been a decent amount of yeast still in suspension. I then added four vials of WLP672 (homebrew size), at room temp. I can't say for certain that the lacto was at room temp. I believe it was sitting out of the fridge for maybe four hours before I added it. There was definitely activity in the barrel for the next 48 hours or so, but I figured it was most likely the suspended yeast chewing through the sugar from the raspberries.

It's now been six months, and the beer doesn't seem to be souring. It has been aging at ~68F (ambient). I know temperature matters with bacteria, so for the last two months the barrel has had blankets on it trying to keep it a little warmer. Either way the beer isn't as sour as I was hoping. It actually isn't sour at all. It tastes great, but it isn't sour. I had planned on letting this beer age for twelve months, so I have about six more to go.

Should I add more lacto, or just let it age?

[Dr_Lambic]

Two things may be happening in this case. The first (and likely) possibility if you're not tasting any acidity in the beer is that the hopping rate was too high for this strain of L. brevis. As a species L. brevis is thought to be slightly more hop tolerant than some strains of Lactobacillus but it still can be strongly inhibited by hopping above 10 IBUs. The second, more broad, issue is that Lactobacillus often produces lackluster souring when pitched into already attenuated beer. My recommendation to further sour this batch would be to pitch a blend of Pediococcus and a low flavor impact Brett like BSI's strain of Brett brux 'Drie'. The Pedio is more agressive than Lacto and should continue to sour the beer given its IBU level. The Brett is needed to clean up any diacetyl that Pedio may produce during its aging and souring process.

Good luck!

[biglakebrewing]

Two things may be happening in this case. The first (and likely) possibility if you're not tasting any acidity in the beer is that the hopping rate was too high for this strain of L. brevis. As a species L. brevis is thought to be slightly more hop tolerant than some strains of Lactobacillus but it still can be strongly inhibited by hopping above 10 IBUs. The second, more broad, issue is that Lactobacillus often produces lackluster souring when pitched into already attenuated beer. My recommendation to further sour this batch would be to pitch a blend of Pediococcus and a low flavor impact Brett like BSI's strain of Brett brux 'Drie'. The Pedio is more agressive than Lacto and should continue to sour the beer given its IBU level. The Brett is needed to clean up any diacetyl that Pedio may produce during its aging and souring process.

Good luck!

Thanks for the reply. I was concerned about the hop levels to begin with. I was hoping since they were ~2 years old that the oils levels would have dropped, and that the actual IBU of the beer would have been ~12. I wanted something dry, and tart without my horse blanket brett flavor.

I think I'll add some WLP650 to the mix and give it another six months. Unless you/anyone has an argument against that blend...

[tjc27]

What if you do another brew with a sour (lacto) ferment and blend the two?

[Dr_Lambic]

Blending with another sour beer is almost always a good option and I agree it could definitely be a benefit here.

I would recommend against just adding Brett brux into the mix. It may produce some nice funk & complexity for you, but its not likely to aid in the souring process at this point. I would personally try WLP655, because it has both the Pedio and Brett that may help. I would also suggest a second addition of fruit in about 3 months. This addition would be to both keep your fruit character fresh and to give the bacteria in the pitch some simple sugars to work with once they've had a chance to establish themselves. When planning for hop additions in Lactobacillus soured beers, the reduction of alpha-acid potential with age doesn't prevent the hops from inhibiting Lacto. The aged hops added to lambic wort add very little in the way of AA but they do inhibit Lactobacillus from taking hold too early in the fermentation and reducing the pH before the yeast have a chance to establish themselves.

[biglakebrewing]

Blending with another sour beer is almost always a good option and I agree it could definitely be a benefit here.

I would recommend against just adding Brett brux into the mix. It may produce some nice funk & complexity for you, but its not likely to aid in the souring process at this point. I would personally try WLP655, because it has both the Pedio and Brett that may help. I would also suggest a second addition of fruit in about 3 months. This addition would be to both keep your fruit character fresh and to give the bacteria in the pitch some simple sugars to work with once they've had a chance to establish themselves. When planning for hop additions in Lactobacillus soured beers, the reduction of alpha-acid potential with age doesn't prevent the hops from inhibiting Lacto. The aged hops added to lambic wort add very little in the way of AA but they do inhibit Lactobacillus from taking hold too early in the fermentation and reducing the pH before the yeast have a chance to establish themselves.

Great info. Before I try another sour, I'll be sure to read American Sour Beers book. Thanks for all of your help.