Bacterial infection occurred during primary fermentation using US-05

[Young Brewing]

Hey all,

Last Sunday I brewed a pretty straightforward blonde for a family vacation in a couple of weeks.

Recipe:

8 lbs​	Pale Malt (2 Row) US (2.0 SRM)​	Grain​	6​	82.1 %​	0.63 gal​
12.0 oz​	Cara-Pils/Dextrine (2.0 SRM)​	Grain​	7​	7.7 %​	0.06 gal​
8.0 oz​	Caramel/Crystal Malt - 10L (10.0 SRM)​	Grain​	8​	5.1 %​	0.04 gal​
8.0 oz​	Vienna Malt (3.5 SRM)​	Grain​	9​	5.1 %​	0.04 gal​
0.30 oz​	Centennial [8.10 %] - Boil 30.0 min​	Hop​	10​	7.2 IBUs​	-​
0.30 oz​	Centennial [8.10 %] - Boil 20.0 min​	Hop​	11​	6.1 IBUs​	-​
0.30 oz​	Samba [7.90 %] - Boil 10.0 min​	Hop​	12​	4.5 IBUs​	-​
0.30 oz​	Samba [7.90 %] - Boil 5.0 min​	Hop​	13​	3.6 IBUs​	-​
1.0 pkg​	Safale American (DCL/Fermentis #US-05) [50.28 ml]​	Yeast​	14​	-​	-​

The brew day went pretty well, done in about 5 hours, and went on to sanitize my big mouth bubbler with StarSan while I cooled down the wort. The only odd thing I noticed is that my packet of S-05 smelled like sour bread when rehydrating but I paid no attention and pitched regardless.

Here I am about 8 days later and it has finished nicely at 1.011, but a layer of pellicle (I think?) has formed on the top and the beer itself definitely has a pleasantly soured aroma. I sanitized the bubbler properly, allowed nearly zero oxygen in, due to pulling gravity samples from the spout at the bottom, and yet an infection occurred. Is there any way that some level of bacteria already existed within the s-05 that could have caused this? Is that scenario even possible? Normally, I would assume I just sanitized improperly but the distinct soured smell of the yeast early on has me thinking whether this could be the case. Either way, I have decided to rack the beer to my keg in hopes that the ph hasn't dropped enough to be noticeable in the finished beer.

If this wasn't meant for a vacation I would probably let this sour because I think the style could play really well, but maybe that's for another brew day. Has anyone had a similar experience?

Picture of the fermenter (this is pellicle right?):

 

[DuncB]

Not convinced sometimes get yeast floating on the top even after normal ferment finished.
I would be interested to know the pH and also the taste. I do tend to taste my gravity samples just to give me a bit of a guide.
If it killed you, you'd know not to drink the rest of the batch!

I've just used a philly sour yeast for a ferment and that just ran with a thin 10-15 mm white foamy krausen for several days then it pretty much fell away and i could just see bubbling coming up.

All is not lost, yet, but time will tell.

 

[IslandLizard]

The big, white slimy bubbles may indicate an infection. If the beer tastes good, let it be, and keep it cold!

Was that pack of US-05 damaged in some way? Previously opened? Were the granules small, solid, well separated (not clumped together) and dry, as they should be?
If they were damp or pastelike that would be a good telltale not to use it. Something got inside, moisture being a main suspect and whatever rides in with it.

I've never smelled inside an opened pouch, but never never found an overwhelming odor escaping either.

 

[Young Brewing]

I don't currently have a working pH tester but I do have one coming in the mail. As for taste, it still tastes pretty malty and a little fruity. It does smell like soured fruit and honestly, in a good way!

@IslandLizard The packet wasn't damaged but the granules were very clumped together and possibly damp. I just remember it being odd enough to be slightly taken back by it. Usually, my rehydrated S-05 smells like a bakery but this one was definitely off.

I am racking it into the keg as we speak, but I am nervous about the bacteria staying past this stage. I plan to bottle these beers after force carbonating and then bringing them to the beach. Do you think that a couple of weeks in the cold will leave the little guys dormant enough to bottle without them showing back up? Never dealt with an infection before, especially when bottling.

 

[DuncB]

The taste test is a good sign I think. If you keep it cold conditioning and carbonated then taste it in a week or so, and maybe test pH for interests sake.
You are counter pressure bottle filling I'd assume from your description.

 

[IslandLizard]

I am nervous about the bacteria staying past this stage.

If there are any, yes, they will stay around until you clean and sanitize the equipment, and thoroughly.

You can clean your keg with a gallon or so of hot (homemade) PBW or Oxiclean, make sure everything gets scrubbed well, especially inside the dip tubes and PRV.

Clean your fermenter with the same, just not too hot, since it's glass (prevent thermal shock). But it's smooth, so give it a good brushing, rinse out well and sanitize. That should take care of it, in case something is in there.
Rubber stoppers, racking cane, tubing, etc. same way. Use brushes.

 

[IslandLizard]

[Rephrased]
Since they're pre-carbonated, you don't have to bottle condition them.
As long as the filled bottles stay cool/cold there should not be a problem in the short run.

Even if they become warmish for a few days, then chilled again, should not cause any explosions.

If there are any bacteria present (not proven yet, but suspected) they won't be very active in smaller numbers, and with alcohol present, won't escalate quickly.

But I'd say drink ASAP, they may get more sour. How long before the beach trip? Oh, I see about 2 weeks. They should be OK, keep em as cold as possible (fridge).

 

[Young Brewing]

Thanks for all of the help guys, going to just keep these super chilled and hope for the best! The first infection had to happen at some point... now off to sanitize for the next 6 hours.

 

[Jayjay1976]

I've been waiting for an infection like yours to happen so I can experiment with it but I'm getting impatient so I picked up some wyeast sour cultures at my lhbs. I guess in the spirit of accidental experimentation I'll just dose a random batch of beer to see how it turns out. Darn my scrupulous sanitation habits! 60 clean batches, I'm such a bore (And intentionally tempting fate!)

 

[brownni5]

I'm skeptical that's a pellicle, unless you've really skimped on your sanitation. I brew intentional sours all the time and have never seen a pellicle develop in a week - not saying it can't happen, just haven't seen it personally. Looks like the tail end of fermentation to me.

Also, with 20 IBU (calculated), there aren't many bacteria that would sour that beer, and nothing that quickly (unless it was really warm - 100 degrees or so), so taste isn't a good indicator anyhow.

IF it is infected, more likely a wild yeast, not a LAB, which may or may not produce an off-flavor.

 

[Young Brewing]

I'm skeptical that's a pellicle, unless you've really skimped on your sanitation. I brew intentional sours all the time and have never seen a pellicle develop in a week - not saying it can't happen, just haven't seen it personally. Looks like the tail end of fermentation to me.

Also, with 20 IBU (calculated), there aren't many bacteria that would sour that beer, and nothing that quickly (unless it was really warm - 100 degrees or so), so taste isn't a good indicator anyhow.

IF it is infected, more likely a wild yeast, not a LAB, which may or may not produce an off-flavor.

This is my first time using a fermenter that is clear because I mostly use buckets so it’s very possible this has been in several of my other beers but it fell before I had a chance to catch it.

This is also my first time using Zamba hops which could be what I am smelling, although I would be surprised if that’s what it was. Still, it’s comforting to hear that I could just be overreacting. I guess I will just have to wait and take a pH sample to see if any actual souring went on, although based on your experiences it seems like that would be improbable.

 

[Garage12brewing]

I never saw infected beer but I dont know what you are looking at that looks infected but I recommand to grab a beer and relax !

 

[Mr. Vern]

This thread makes me wonder about my last 2 brews as they looked a lot like this (big bubbles, high tension holding bubbles for a long time). I assumed it was totally normal for this strain, or, more likely the extra wheat protein in my 1st fermentation with US-05.

I shrugged it off and chalked it up to the protein and yeasties that like to stick/float. 2nd brew had similar krausen with a small amount of re-pitched slurry (no wheat this time). 1st beer tastes very clean, 2nd beer is being transferred tonight and off-gas smelled lovely in the fermentation chamber.

Both brews were low gravity 4% ABV. I did not have much of a cold break before transferring which may be additional surface tension for bubbles to stick around on. I am speculating here, still trying to adsorb knowledge.

YMMV indeed... many variables at play.

 

[odie]

looks kinda normal post-krausen to me...what did it look like before you took the picture? Is this right after krausen fall or several days later? Was the top clear and then this popped up or is this what was left after peak krausen? without seeing a progression of pictures it's kinda hard to just say "that looks bad, just dump it".

No two fermentations are ever gonna look identical...close but not identical...I doubt anyone stares at their fermenter 24/7 or videotapes it for playback.

 

[The_CuRe]

I had a batch like this after the batch in which I attemped a mango dry hop, i rested my glass fermenter with clorine 15% for 1 day and did not happen again.

 

[IslandLizard]

I doubt anyone stares at their fermenter 24/7 or videotapes it for playback.

Not until we have Tilts with a built-in camera...

 

[Young Brewing]

looks kinda normal post-krausen to me...what did it look like before you took the picture? Is this right after krausen fall or several days later? Was the top clear and then this popped up or is this what was left after peak krausen? without seeing a progression of pictures it's kinda hard to just say "that looks bad, just dump it".

No two fermentations are ever gonna look identical...close but not identical...I doubt anyone stares at their fermenter 24/7 or videotapes it for playback.

This was about 4 days post-Krausen and it was clear prior to taking the picture. Seemed to pop up sometime inbetween my gravity reading on 6/17 and when I noticed it on 6/20.

It’s been cold crashed and carbonated so after work today I’m gonna pour one and report back.

also good call on the chlorine @The_CuRe , might have to go ahead and do that just to be safe.

 

[odie]

This was about 4 days post-Krausen and it was clear prior to taking the picture. Seemed to pop up sometime inbetween my gravity reading on 6/17 and when I noticed it on 6/20.

that would make me suspicious too

 

[monkeymath]

pulling gravity samples from the spout at the bottom

I can't say whether you actually *do* have an infection, but pulling (multiple) gravity samples from a spout at the bottom is not a great practice imho. First: let ambient air bubble through your wort/young beer, which is not great due to oxygen and risk of contamination, but probably not a huge issue.
Second: a spigot attached to a fermentor can be difficult to clean. It depends heavily on the exact geometry, but with my plastic Speidel, you'd invariably have some remaining wort drying inside the spigot (but outside the fermentor), which is quite likely to harbour bacteria. Next time you open the valve, that dirty "outside" part of the valve is pushed into the fermentor, where it comes into contact with your young beer... Not ideal!

Before someone jumps in and says "I do that all the time and I've never had an infection": I'm not saying you were necessarily bound to end up with an infection every time, just that it can be a certain risk.

 

[hotbeer]

If I worried about all the stuff that appears and disappears on top of my fermenting beer, then I'd have to quit making beer.

Even if I suspected infection, I would not do anything different. I'd still even bottle, wait, then try it.

 

[Young Brewing]

I can't say whether you actually *do* have an infection, but pulling (multiple) gravity samples from a spout at the bottom is not a great practice imho. First: let ambient air bubble through your wort/young beer, which is not great due to oxygen and risk of contamination, but probably not a huge issue.
Second: a spigot attached to a fermentor can be difficult to clean. It depends heavily on the exact geometry, but with my plastic Speidel, you'd invariably have some remaining wort drying inside the spigot (but outside the fermentor), which is quite likely to harbour bacteria. Next time you open the valve, that dirty "outside" part of the valve is pushed into the fermentor, where it comes into contact with your young beer... Not ideal!

Before someone jumps in and says "I do that all the time and I've never had an infection": I'm not saying you were necessarily bound to end up with an infection every time, just that it can be a certain risk.

Thanks for all the feedback here! Actually thought that by using the spigot I was reducing my chance of infection but I totally didn’t even think about pulling oxygen in as a byproduct.

I think for now I will stick to using it as a closed transfer option, which I have yet to do but look forward to trying next batch.

 

[Albionwood]

Whether it is infected or not I can't say, but that is definitely not a pellicle. If the beer is infected with a pellicle-forming organism, it might eventually develop into one, but what you show in the photo is not what a pellicle looks like.

 

[Knightshade]

Not until we have Tilts with a built-in camera...

I've toyed w/the idea of using the raspberry pi my son built for a birdhouse to look in on my ferment every once in awhile. Camera attached w/infrared lights..especially since it never actually got installed in the dang birdhouse....

 

[DuncB]

I've toyed w/the idea of using the raspberry pi my son built for a birdhouse to look in on my ferment every once in awhile. Camera attached w/infrared lights..especially since it never actually got installed in the dang birdhouse....

Try one of these it's ready made, uses infra red light so less risk to the brew, then use the PI for something else. Can access it on the road and you can even talk to the beer with the inbuilt microphone!
https://www.amazon.com/Security-Two-Way-Storage-Monitor-Android/dp/B0771HZPLT

 

[Young Brewing]

The beer looks great, and tastes even better!

This whole post was essentially the reason behind RDWHAHB, Cheers!

 

[DuncB]

You are right looks good. Will probably get better as well.