Does cold storage always prevent infection?

[Amadeo38]

I’ve been battling a problem with an apparent infection that I can’t really tie down. The result is a bodyless, dry, tasteless beer that’s overcarbonated. They’re not super hard to drink or anything, just not enjoyable because of the lack of body and flavor.

It first happened in a brown ale brewed October 2018 which I aged on mamey/sapodillo for several weeks (in primary after primary ferm finished), then bottled. I assumed the overcarbonation occurred because the fruit re-fermented in the bottle and forgot about it.

The next beer was an oatmeal stout the next month, which I kegged and was initially fine. However, when I ran out of cold storage space a couple months later, I moved the keg to room temp and voila - same problem.

The current beer is a particularly huge bummer. An imperial maple coffee porter aged for six weeks on oak. It was amazing at bottling. Now three weeks later it’s got the same problem.

I don’t have this issue in any other beers except those that sit at room temp for some period of time (bottled or kegged). Never happens to beers kept in my storage fridge at 42F. Even after months. Has anyone had a similar problem?

My current plan is to de-gas a sample of this porter to see what the FG is at this time. When I bottled it was 1.018. I’ll bet it’s around 1.000 now. I’m also going to bottle a couple of my light beers I have on tap and let it sit at room temp for two weeks and taste it to see if the same thing happens. Then I’ll probably replace all cold side plastics before I brew or transfer another batch.

 

[Qhrumphf]

Cold doesn't "prevent" infection. It often (though far from always) will slow it.

It does sound like you've got something in your system.

I would heat sanitize (boil, or at least near boiling water with at least 15 mins contact time, or better yet bake or autoclave to sterilize) anything where you can (ie not plastic or vinyl that can't take the heat). Heavy sanitizing (namely, bleach followed by rinse) everything else non-pourous and non-scratchable (glass carboys and the like).

All plastic and rubber gear that can't tolerate sustained boiling temps (bucket fermenters, bottling buckets, siphons, tubing, etc), I would just replace.

From there, your cleaning and sanitizing needs an overhaul.

You're reasonable to assume it started with the fruit. If it was fresh fruit and you did nothing to pasteurize it, you probably introduced a boatload of wild yeast and bacteria (fresh fruit is covered in it), that proper cleaning and sani should have wiped from your system after that batch.

Alternatively, if you brewed a Saison, particularly if using French or Belle Saison strains, this sounds like textbook diastaticus cross contamination.

 

[Amadeo38]

Thanks for the reply. Yeah, I didn’t mean *prevent* infection as much as I meant prevent it from showing up. The last saison I made was in April 2018 with French Saison yeast but didn’t have any problems with bottled beers after that batch and no evidence of a film on equipment. I’ve brewed 19 batches since that saison, and like I said, only the three out of those 19 were infected. And this includes a batch of semi-sweet mead that is sitting at room temp corked and is still as can be. I bet you’re right that the un-pasteurized Mamey is what did it.

I just tasted the porter after it came down to room temp and the carbonation dropped and the maple coffee flavor has returned. Not de-gassed enough yet to test gravity. I guess I’ll just have to decant and de-gas them before drinking :/

I’m going to boil my camlocks and ball valves, replace my fermenting bucket and cold-side equipment, and look into the best method for cleaning my 6 gallon glass carboy. Is it okay to boil high temp silicon tubing? Expensive to replace it all...

 

[TechFanMD]

Cold storage, especially at consumption temps will slow, but not stop, pretty much any infection.....for a lot who keg different beers or ciders, they rely on consuming faster than re-fermentation occurs.

This is very interesting because it doesn't taste bad....just over carbonated and tastesless (I would probably describe it as 'thin).

Let us know how the porter measures.....that would be very interesting. My gut says that if it were contamination due to the fruit in that beer, the taste would be sour or unpleasant.....but it could be a lot of things.

As an experiment, this is cool. For you and your system....let's figure it out and get you back to awesome beer.

 

[Amadeo38]

This is very interesting because it doesn't taste bad....just over carbonated and tastesless (I would probably describe it as 'thin).

Let us know how the porter measures.....that would be very interesting. My gut says that if it were contamination due to the fruit in that beer, the taste would be sour or unpleasant.....but it could be a lot of things.

Now that I’ve let some of the carbonation fall out and it warmed, the porter tastes pretty good, but not perfect. Would be better carbonated optimally, but not a total loss if I can get a bunch of them in the fridge to slow this down. I can’t say I let the Mamey Brown Ale warm up and de-gas long enough to see if the same held true.

I’m not sure how long a beer has to sit before you can accurately check it with the hydrometer. It’s been an hour and it’s still reading 1.016, which is close to where it was at bottling.

The fact that it’s not a bad flavor/sour and is simply overcarbonated and lacking body leads me to believe it is some form of diastaticus. Probably from the Mamey since I didn’t have trouble with beers stored room temp immediately after the French Saison yeast.

 

[Amadeo38]

Just checked the de-gassed porter and it’s sitting at 1.014. Not as low as I had thought.

Does the fact that it’s a gusher and the other symptoms I described with a lack of bad/sour/funky/off-flavor definitely suggest diastaticus? Is there a chance I don’t have to replace plastic items that I can clean the insides of very well, such as my transfer siphon? Or is diastaticus super resistant to cleaning with strong PBW and proper StarSan?

 

[RPh_Guy]

Does the fact that it’s a gusher and the other symptoms I described with a lack of bad/sour/funky/off-flavor definitely suggest diastaticus?

No. Saccharomyces is only one of many wild yeast genera.

Is there a chance I don’t have to replace plastic items that I can clean the insides of very well, such as my transfer siphon?

Yes, there a chance. How much risk you're willing to take is up to you.
I handle diastaticus strains, Brett, wild yeast, and bacteria.
I use one set of equipment for all my batches without ever cross-contaminating (and I bottle everything).

Cleaning is paramount. I use a quality percarbonate cleaner like PBW and a standard no-rinse sanitizer like Star San.
At minumum, everything gets rinsed immediately after use.

Or is diastaticus super resistant to cleaning with strong PBW and proper StarSan

Wild microbes* themselves are not resistant, however there is some possibility of a biofilm formation, which does help them defend against chemical cleaners... particularly on plastic since it's easier for microbes to adhere. That's why heating is useful.

* Some commercial strains like Belle Saison for example are known to form biofilms.

@Qhrumphf gave solid low-risk advice for decontamination, but that's not the only way to do things.

Hope this helps

 

[Qhrumphf]

Silicone I'd imagine is fine to boil.

Glass, I'd use bleach, then thoroughly rinse, air dry for a couple days to let any chlorine degas, then for good measure PBW and then sani.

If you feel like getting ballsy, mixing acetic acid (vinegar) and hydrogen peroxide will form a solution (equilibrium) of peracetic acid. It's what the vast majority of pros use. You won't likely be able to form something as effective as an industrial preparation, which may be for the best since the stuff is quite dangerous when concentrated.

And I personally do not like Star-San. It's foaming properties mean one excellent use, leak testing pressurized vessels. Otherwise, I far prefer Iodophor. It doesn't foam nearly as much, and it's a more effective killer.

 

[Amadeo38]

Thanks for your help, everyone. The high temp silicone tubing and all camlocks/spigots/metal pieces are autoclaving in the instapot currently. I’m placing an order for new cold side plastics at morebeer now, and am excited to have a big mouth fermenter with spigot in lieu of a bucket! I’ll look up the proper bleach ratio for cleaning my glass carboy, but it is currently cold-crashing with a Best Bitter in it, so that will come later.

Given that I rarely bottle non-sour beers anyway (and yes, I have all separate equipment for my sours), I’m just gonna stick to kegging and keep things cold-stored going forward just in case.