What is this infection, what should I do with it?

[Bradmont]

(This is a repost since I didn't get any responses in the Lambic forum)

I have a random brew that I made with some leftover grain and stuff a couple months ago, details here - Something Something Belgian. Decided to pitch some belgian yeast and ferment open for a few days until the krausen died down, then racked to a carboy (with the yeast cake). Had a taste maybe 5 weeks ago and it was definitely weird, but kind of good -- lots of peppery esters and such. It's been in my closet since, and I recently pulled it out and had a look, only to find it infected (can't say I'm terribly surprised, though.) So can anyone identify this infection?

To see larger resolution look here.

I had a taste tonight (the pellicle is broken in the picture from where I took the sample). It still has a lot of odd esters, the carboy smells almost like fermenting wine, still tastes peppery, and a little too roasty (put too much chocolate malt in). I think I detected a bit of a sour taste, but with all the other strong flavours going on I couldn't be sure; not to mention that I haven't had much sour beer so I don't really know what to look for. If this winds up being "Something Something Sour Belgian" I wouldn't mind, but I have no experience with critters other than yeast.

So my question is, what is this infection? Should I do something to get rid of it, or let it ride? Or something else?

Thanks!

 

[unionrdr]

Well,maybe you got lucky on the open part of fermentation & got the little critters that make those sour ales. You say it tastes ok at the moment. I say,let it ride till it clears to a slight haze & try it again. Who knows,this may just be a good thing. But I'm sure someone with more knowledge of Belgian beers will speak up.

 

[Bradmont]

Yeah, that's kind of what I'm hoping!

 

[unionrdr]

Well,I figured since they still use open fermenting tubs in Belgium,you may just have simulated that. Seems like a left over from the Bronze Age to me.

 

[twelfthman01]

Without a doubt (or a very small one) Lactobacillus!

How sour do you want it? Keg or bottle/carb then refrigerate asap if you like it the way it is. OR if you want to experiment a bit let it ride a few weeks and if its a brown ale of some sort you could end up with a piece of history. What I mean is a traditional Old World Brown Ale or Porter, soured before serving.

I had a brown ale do this to me not 3 months ago. I could detect a hint of sourness, but I thought it was good as is and so kegged and carbed. I even sent bottles with my wife to her work and ALL approved!

Word of caution though: if thats a glass carboy, good! if its plastic its now a Lactobacillus fermenter. That stuff is impossible to get out of plastic. I know from experience.

 

[Bradmont]

Cool! Thanks!

It's not terribly sour at this point, I could barely taste the sourness. I'll absolutely let it ride a while longer. And yes, it is a brown ale.

And yes, it surely is a glass carboy.

Hey, any idea how I could keep a culture of this stuff for future use if I want to? Could I just wash the yeast as normal and throw it in the fridge, or would I have to do something special?

 

[jtakacs]

unlikely - lacto doesn't floc like yeast - as far as i know, it stays in suspension. you could pull off a sample and drop it into some pasteurized apple juice and try to grow it...

 

[Bradmont]

Hmm... do you know of a method for harvesting/keeping some?