Did I accidentally make a sour?

[Iowa Brewer]

Hey all,

I made my house witbier last month and everything seemed to go as it always does. Good strong ferment, followed by a diacetyl rest (strange for a wit, yes, but I had a bad experience), and a month in the fermenter. No signs of infection, or anything out of the ordinary.

After kegging it, my wife and I noticed a prominent yogurt aroma on the nose, a tangy yogurt initial taste, but then followed by a nice mellow and malty finish.

The only thing I did differently was use SafAle-05, which I had on hand, instead of SafAle BE-134, which is my normal go-to for this beer. I also didn't cold crash this time, as I wanted to get that wheat-y haze.

Any of you more experienced brewers/micro-biologists/chemists have an idea of what's going on here?
At the end of the day, it's weird, but it's good, so we'll be drinking it.

Thanks and happy brewing!

 

[Dgallo]

Lacto infections would Tend to take place at room temperature or warmer. So i have a few questions;

1) how good did you clean/sterilize your keg, draft lines, and taps?

2) How many ibus was your beer?

3) have you used a hop tolerant lacto strain in the past?

 

[Iowa Brewer]

Hey, Dgallo, thanks!

1) I use StarSan, and am quite (very) careful to the point of obsessive. The keg had StarSan in it for few weeks, and I tip it to ensure both sides. I also run the sanitizer through my lines and taps.

2) 13-ish IBUs

3) TBH, I’m not sure what this means.

 

[shoengine]

Do you have a pH meter?

 

[Gnomebrewer]

3) TBH, I’m not sure what this means.

Lactobacillus (bacteria) strains are what mostly give sour beer (and yoghurt) it's sourness. Pediococcus is also used in some long-aged sours (eg. Lambic) but takes a lot longer than a month to do its thing. Most strains of Lactobacillus are very intolerant of hops - even 13IBU is enough to inhibit souring (it's one of the reasons hops were originally used in beer). The only way you're likely to have a hop tolerant strain hanging around is if you deliberately used one (purchased) in the past.

Do you know anyone who regularly drinks sours that might be able to taste your beer and give some feedback? Could the hops have been old - cheesy hops could be mistaken for yoghurt?

 

[Iowa Brewer]

Do you have a pH meter?

I don’t, but this might be just the excuse I need

 

[Iowa Brewer]

Lactobacillus (bacteria) strains are what mostly give sour beer (and yoghurt) it's sourness. Pediococcus is also used in some long-aged sours (eg. Lambic) but takes a lot longer than a month to do its thing. Most strains of Lactobacillus are very intolerant of hops - even 13IBU is enough to inhibit souring (it's one of the reasons hops were originally used in beer). The only way you're likely to have a hop tolerant strain hanging around is if you deliberately used one (purchased) in the past.

Do you know anyone who regularly drinks sours that might be able to taste your beer and give some feedback? Could the hops have been old - cheesy hops could be mistaken for yoghurt?

thanks! That’s pretty cool about the hops! I do have some one I could ask, and think I will.

I believe the Saaz were pretty fresh. Not an old pack and I kept it in the freezer.