[lucy]

So like I said, after a little over three years of regular brewing (about every 3-4 weeks) I think I have a batch that has gone bad. On Dec. 26, I brewed a saison. Everything during the brew day and fermentation went perfect. At the start of fermentation it was at 70, then slowly racked it up to 80 degrees. I checked the SG a little over a week ago and it was down to 1.004 and tasted great. I was waiting until a keg cleared up before I transferred. Well, last night I kicked a keg and cleaned it out. I went to transfer the Saison and there was a thick layer of bubbly white mold on top. I've never seen this before. I can only assume it's an infection beyond repair. Could the simple act of checking the gravity have caused such an infection? I know it's plausible, but I guess I'm in denial.

[norcaljp]

I would taste the beer. If it tastes fine, I'd just rack from below the gunk and roll with it.

[reverseapachemaster]

What you're seeing on top is a pellicle and not mold so that's the good news. The bad news is that you definitely have something in there other than regular brewer's yeast. What yeast strain did you use? Some of the saison strains out there are blends that include brett. Brett would give you that pellicle.

[majorvices]

yeah I would guess it is brett or acetobacter or both. Taste it before you dump it. Agree with comment that some of these strains have brett in them already.

[lucy]

I used Wyeast 3711. I just pulled a sample and while it doesn't taste bad, it certainly doesn't taste good. Not rotten, but definitely off from the sample I pulled last week. I don't know if I can drink 5 gallons of it.


Here's a photo:
http://imgur.com/XqLA1y3

[reverseapachemaster]

3711 is pure brewing yeast so somewhere along the way you got some type of wild infection. It's hard to say exactly where it originated without knowing your sanitation processes and what happened to the beer from the end of the boil until you saw the pellicle. If things seemed alright a couple weeks ago and then this showed up it is fair to suspect it showed up with that last gravity reading or some other recent opportunity.

If you don't like it now you probably won't like it down the road. Sometimes wild beers taste pretty bad early on and develop nice flavors if you think brett-type flavors are pleasant. Often the unpleasant flavors linger or magnify. If you're not one to enjoy brett beers then just dump it now. It's not going to to go back to what it used to be. If that is a class of beer you enjoy then maybe you want to let it develop for a few months and see what happens.

[brewinhard]

That is one gnarly pellicle though. Brains on another planet...

[lucy]

I think I'll just rack it again (well below the gunk), set it aside and taste it in another month or so. I really hate the idea of dumping an entire batch.

[tommymorris]

I have never dealt with an infection intentional or otherwise, but, I am thinking you may want to set it aside at fridge temps if you want to stop the growth of the infection.

[Joe Sr.]

I think I'll just rack it again (well below the gunk), set it aside and taste it in another month or so. I really hate the idea of dumping an entire batch.

We've all dumped batches now and then.  It hurts, but not as bad as drinking nasty beer.  Every sip is a reminder of that something went wrong.

That said, I have two batches I should dump.  I just haven't needed the kegs yet.  But that day is coming.

[ynotbrusum]

Sometimes the Brett works fine with your base beer - assuming that it migrated from a "domesticated" Brett or a wild one that isn't too funky.  If you were to rack it, the Brett would likely take hold again in time -it makes the pellicle to keep the O2 out, so it can be okay for a while.  If you rack and keep it cold, the Brett will not be active in my experience.

All is not necessarily lost is my point.  I had a Gose with just the lightest pellicle of Brett in the primary, which I kegged and it was quite good!

[ajk]

Brett usually takes a while to get going, so it's unlikely it was introduced during the gravity check. It probably happened around the time it went into the fermentor. Could be an infected starter or unsanitary equipment between the kettle and the fermentor. I suggest thoroughly cleaning your cold-side equipment and using a sanitizer you don't normally use (e.g., Iodophor instead of StarSan) before your next batch.

[Al Hounos]

I think I'll just rack it again (well below the gunk), set it aside and taste it in another month or so. I really hate the idea of dumping an entire batch.

I'm no wild beer expert, but it's my impression that if the beer tastes ok and you want to see where it's going, you should just leave it alone for a few months. If it's a bacterial infection, exposure to oxygen could cause nasty flavors that really will ruin the beer. As ynot said, one theory about pellicles is they are there to protect the beer from oxygen or competing microbes. Again, I'm certainly no expert in this area.