Potentially infected brew

[Chad D]

I am relatively new to brewing (this is my third batch). I've been using, to the best of my knowledge and experience decent sanitation practices, carefully sanitizing equipment with Starsan.

This batch was a beer kit that included a lager yeast, which didn't realize when purchasing the kit (my screwup) and I don't have a lagering fridge. I was able to get it at a good ale temp during primary and secondary fermentation, but as might be expected I kept losing solution out of the airlock (I assume due to rapid yeast metabolism) during primary. During secondary fermentation the beer developed a film and semi thick layer of what a beige "crust?) The top of which looked in texture like popcorn ceiling material. I thought perhaps it was pellicle, but last night I decided to take a small taste of the brew and it did not taste sour or bitter or bad, but did have a somewhat lambic flavor.

I didn't see any discoloration, I'm just trying to figure out if it is safe to drink? I assume it did get some wild yeast strains due to the lambic flavor, but would like to not toss the beer if I don't have to. I'm including a picture that no longer has the 'crust' (which might be krausen?) Due to having been disturbed. Most appears now at the bottom...

What is the best way to determine if your beer is unsafe to drink due to mycotoxins or other potentially dangerous infections?

Also it looks like the airlock is bubbling again and this has been in secondary for a little over a month since I've been procrastinating making a decision..

Thanks in advance!

 

[hotbeer]

That just looks like you had a really good krausen that left a lot of yeast and other crud on the sides of the FV. Along with the crud and yeast rafts on top.

As for whether it's safe to drink... well, most infections of beer are not toxic to you any more than is the alcohol produced. I'd go ahead and proceed as is normal.

If you still have some trepidation about it after it's bottled/kegged, conditioned and ready for the glass, then , then use your smeller and taster. If it passes that, then don't drink yourself silly with it on the first day. If 24 hours later you feel normal still, then it's likely good.

As for the bubbling again. Bubbles doesn't necessarily mean it's still fermenting. Might be just CO2 coming out of solution from temp and atmospheric pressure changes. However I have had beer in the FV bubble off and on for upwards of six weeks. Those turned out to be some of the best beer I've made.

Bubbling does tend to stir up the trub and yeast. So I almost always wait till it bubbles no more for a few days and the stuff suspended in the beer has gone to the bottom. That leave a clear and cleaner tasting beer IMO.

 

[Chad D]

That just looks like you had a really good krausen that left a lot of yeast and other crud on the sides of the FV. Along with the crud and yeast rafts on top.

As for whether it's safe to drink... well, most infections of beer are not toxic to you any more than is the alcohol produced. I'd go ahead and proceed as is normal.

If you still have some trepidation about it after it's bottled/kegged, conditioned and ready for the glass, then , then use your smeller and taster. If it passes that, then don't drink yourself silly with it on the first day. If 24 hours later you feel normal still, then it's likely good.

As for the bubbling again. Bubbles doesn't necessarily mean it's still fermenting. Might be just CO2 coming out of solution from temp and atmospheric pressure changes. However I have had beer in the FV bubble off and on for upwards of six weeks. Those turned out to be some of the best beer I've made.

Bubbling does tend to stir up the trub and yeast. So I almost always wait till it bubbles no more for a few days and the stuff suspended in the beer has gone to the bottom. That leave a clear and cleaner tasting beer IMO.

Thanks for your reply, that's sortof the direction I'm leaning now. I'm sipping on some out of the hydrometer beaker the fg is definitely lower, so I assume there's enough alcohol in it to kill a fair number of bacteria!

I'll drink a few ounces today and if I'm not having any gastro issues i'll bottle it tomorrow.

 

[mashpaddled]

That looks like a very normal fermentation where the krausen has not yet dropped out. Yeast can remain in suspension or even float krausen for a while which can give beers a sourish, yeasty flavor. That's exactly what seems to be going on here. If you have the ability to chill your beer and keep it cool for a few weeks, give that a try and see how the beer is then. Most likely you just have a lot of lager yeast floating in suspension that benefits from cool aging.

 

[Chad D]

That looks like a very normal fermentation where the krausen has not yet dropped out. Yeast can remain in suspension or even float krausen for a while which can give beers a sourish, yeasty flavor. That's exactly what seems to be going on here. If you have the ability to chill your beer and keep it cool for a few weeks, give that a try and see how the beer is then. Most likely you just have a lot of lager yeast floating in suspension that benefits from cool aging.

Awesome, thanks for the advice. This is the first time I've messed with lager yeast so it seems to be a slightly different beast if you don't have the means to ferment under 60 deg.

 

[hotbeer]

If your FG ends up way below the expected FG, then that might indicate the beer is infected. I once had a beer go all the way to 1.001 and it was both sour and not a enjoyable taste. Though I drank quite a few bottles of it. None with any notable affects other than I didn't like the taste. I was hoping it'd get better. But over six month time sampling every so often, it never got better.

There are all sorts of infections from wild yeast and bacteria that are not toxic. And the non-toxic ones will be the most likely. Some make your beer taste sour, some make it taste like yuck.

And with any, there is a factor of what took hold of the beer first. If the yeast you pitched took hold first, then you are in much better territory. If we always ensure we do a healthy pitch or even over-pitch the yeast. And make sure the ideal fermentation temps and other conditions are met. Then it adds an additional layer of safety to our sanitation layer of safety.

 

[mashpaddled]

Awesome, thanks for the advice. This is the first time I've messed with lager yeast so it seems to be a slightly different beast if you don't have the means to ferment under 60 deg.

A few lager strains work alright over 60F but generally they give you those cleaner fermentation flavors at cooler temperatures. The second struggle is getting the beer to clear up because lager yeasts are poor flocculators.

Depending on the temperature in your area, you might be able to stick your fermentation vessel in a cool area of your house/garage and let it clear up without any fancy equipment.

 

[Bobby_M]

What was the original gravity pre-fermentation? What brand/strain of yeast did you pitch? Approximately what temperature did it ferment at? How long was it in the primary fermenter? How long in the secondary?

 

[Clint Yeastwood]

I would say drop it for now and report back in a couple of weeks. It looks totally normal.

No reason to be in a hurry, unless you only have one fermenter. In which case you need to buy more fermenters. And believe me, you will.