Gusher Infection or Something Else?

[Billo355]

Recently I have experienced an odd issue. I had a batch of porter seemingly come down with a gusher infection. Super carbonated, foams when you open it, not much taste.

My next batch has shown some similar traits - even though I cleansed and sterilized the heck out of every step. It doesn't seem to be a full blown issue - but the head is a bit much. Now I've went to open some older beers - from batches that have shown no sign of anything bad and they are foaming as well (still taste ok.)

Is there anything else that could cause this? Can the infection come post bottling? Or perhaps the conditions in my basement are causing the foam overs? Temperature? Humidity? Any ideas?

Thanks!

 

[Evan!]

First , FYI, you're not "sterilizing" anything, you're sanitizing.

Anyway, for what it's worth, both of my infections (2 batches in 67) have come after bottling. I never did figure out exactly what the problem was, though I did notice that the common thread between them was that they were both dry-hopped with hop pellets. That shouldn't have any effect, but who knows?

If these are actually infections, then the beer will taste very dry and astringent, probably a little sour depending on which kind of beast got in there. If they're just over-carbed, then, assuming you're using the right amount of priming sugar, I'd say that the culprit is probably that they're not completely finished fermenting when you bottle them. I've had a couple batches stall short of my desired FG, and I just assumed they were done because I had a stable terminal gravity over a few days. Turned out that they weren't done, and when I added the priming sugar, it kick-started the yeast and they fermented too much in the bottle and turned into over-carbed brews.

Temp/humidity shouldn't have any effect on anything. Not saying anything for sure, but my guess would be that there's still a bit of fermentable sugar in your beer when you bottle it, at least on the batches that still taste okay.

The real way to tell is to pour a bottle of each into a cup and leave it for a day so it can offgas all its co2. Then take a hydrometer sample---if it's lower than your previous FG reading, then yeah, that's probably what happened. If it tastes sour, on the other hand, it's probably an infection.

 

[david_42]

Porters can also gusher because the yeast have adapted to the caramelized malts. I've noticed my porters will pressurize in the keg without priming, if I let them sit 5-6 months.

 

[ronrad]

last batch of beer i kegged had a high finishing gravity (or so i thought) It produced gas in the kegs, i kept them bleed down so the co2 would not get to high for the yeast but i tried one keg yesterday, the beer is cloudy, and somewhat sour almost a vinegar taste but oxygen was kept away from it. is this an infection and will the kegged beer get worse?

 

[Hoosierbrewer]

I had the same problem with a stout. It was great for about 8 months and then it started gushering.