Over carb from bacteria?

[Bheher]

Hey guys I have had my last 4 batches all overcarbed some even exploding. I was bottling with 3/4 cup sugar but last time scaled down to 4 oz which is a bit bigger then 1/2 cup and it was still overcarbed. I am pretty good on cleaning so I am looking for where an infection could be. Is this bacteria on the surface in my fermenter? I kinda thought it would be hop oil or something but I am trying to figure out if I am getting infected someplace in the process.

Thanks!

http://www.flickr.com/photos/brettheher/4777906469/

 

[japhroaig]

Not an infection most likely--bacteria that would produce that much CO2 more efficiently than yeast and don't have an aftertaste (to my knowledge) don't exist. If they did, and I'm not joking, I would use them for Swiss cheese (propianic bacteria is just too fickle).

The most likely explanation is sugar from your malt that didn't finish getting eaten by the yeast before you bottled. Of you make bog beers fr extract that is what I'd put my money on (or mash AG big beers above 151f).

 

[cfonnes]

Brett? What was your gravity when you bottled?

 

[Bheher]

OK they def dont taste bad but I do mash almost everything over 151 (I am usually in the 154 area) but none of me beers are big beer. I am usually in the 1.05 to 1.07 range.
One other thing I have noticed with my beers is that a lot of times hop flavor wont come thru too well as the beers have a somewhat malty taste. But at the same time I always hit my target FG which is usually around 1.010

 

[Bheher]

cfonnes- the gravity when I bottled was 1.010 it was supposed to finish at 1.011 per the SNPA clone thats posted on here
https://www.homebrewtalk.com/f66/high-sierra-sierra-nevada-pale-ale-88930/

 

[japhroaig]

Well, I am not aware of a bacteria that can do what you are saying, so the Sherlock holmes in me says too much sugar somewhere in your equation.

Are they still over carbed at 38F?

 

[Bheher]

japhroaig, yes even after sitting in the fridge for a week they are the same.

 

[japhroaig]

Crack open all the bottles, let them stabilize, and recap. Next time use 3oz and report back. I expect pics and samples

 

[marubozo]

Could be wild yeast of some sort or something. I lost a whole batch somehow, which was probably due to a bug in the bottling bucket somewhere since it got all the bottles and the beer tasted fine prior to bottling.

But I had a beer that came out way over carbed. You crack one open and foam would gush out. Even if you left them in the fridge for a month. This was back when I was just doing extract kits and everything came pre-packaged so I know I didn't add too much sugar or anything like that.

The interesting thing I found is that after the first few weeks or even a month after bottling the beer tasted great, even if slightly over carbed. In fact, I gave a few out to friends who were helping us move and they called later to say how great it was. But over time they just got worse and worse. After a few months they became undrinkable, and even after I tried to give them even more time they eventually started tasting like Satan's anus. I eventually just dumped the rest.

So, not saying this is what happened to you or anything, but if you were at your final gravity and didn't use a crapload of sugar, it is possible that a wild bug got in somewhere during bottling.

 

[Bheher]

japhroaig- Ok i didn't know I could stabilize and recap. Thanks!
Will try the 3 oz next time as well.

 

[Bheher]

marubozo- Thats what I figured too, that it was a bug. But I just opened a bottle of brew that was about 3 months old and it taste the same just really foamy when I open it. But mine has the same effect as yours did, they are good until about a month and a half then all of a sudden they foam all over the place when you open them. Maybe I will try and bottle with my buddys bucket and wand next time and see if that changes anything.

 

[Bheher]

m

 

[japhroaig]

Recaping is a last resort, but it does work.

I am dead certain an infection cannot cause overcarbonation. If your yeast can't do it, bacteria can't. There *must* be food for a bug to eat, and that means either 1) sugar, 2) lactic acid, or 3) alcohol. You would taste it if it was #2 or #3.

 

[Yooper]

Recaping is a last resort, but it does work.

I am dead certain an infection cannot cause overcarbonation. If your yeast can't do it, bacteria can't. There *must* be food for a bug to eat, and that means either 1) sugar, 2) lactic acid, or 3) alcohol. You would taste it if it was #2 or #3.

I would disagree. A gusher infection certainly can cause overcarbonation, and can be a common problem. Of course, lacto tastes sour, but not in early stages, so it could be early lacto (but not likely).

I think it's a gusher infection. It would get worse with time, with the beer being thin and dry, but not necessarily "bad" tasting.

 

[japhroaig]

I have heard of 'gusher infections' from several sources, but I have never seen a specific cause outlined. What strain of bacteria causes it, and why can they suddenly consume sugars that yeast can't consume? And why don't they cause off flavors? Bacteria and yeast don't (to my knowledge) only produce CO2 when they consume sugar, the yeast pitched (unless it was virtually dead when pitched) will be the dominant strain, and bacteria just can't produce the much CO2 that I'm aware of.

Gushers must be related unfermented sugar that your pitched yeast hasn't eaten yet. This can happen for a lot of reasons, but I really, really doubt an infection is the cause. I think it is much more likely that the pitched yeast is consuming higher sugars at a much slower rate, but it's not due to outside contamination. For what it's worth, I am not a chemist, biologist, or food technician

 

[Yooper]

I have heard of 'gusher infections' from several sources, but I have never seen a specific cause outlined. What strain of bacteria causes it, and why can they suddenly consume sugars that yeast can't consume? And why don't they cause off flavors? Bacteria and yeast don't (to my knowledge) only produce CO2 when they consume sugar, the yeast pitched (unless it was virtually dead when pitched) will be the dominant strain, and bacteria just can't produce the much CO2 that I'm aware of.

Gushers must be related unfermented sugar that your pitched yeast hasn't eaten yet. This can happen for a lot of reasons, but I really, really doubt an infection is the cause. I think it is much more likely that the pitched yeast is consuming higher sugars at a much slower rate, but it's not due to outside contamination. For what it's worth, I am not a chemist, biologist, or food technician

Several different bacteria and wild yeast can cause gusher infections. They can consume dextrins, and sometimes there isn't a bad flavor simply because it's not a bad tasting wild yeast. You can use wild yeast to ferment ciders, too, and they'll go dry but not taste bad.

There are many, many strains of bacteria and wild yeast that can ferment fruits (ever see birds get "drunk" off of half fermented fruit?) and our beers. Most will make the beer taste bad, but gusher infections don't always taste bad. They just ferment more than your desired yeast strain's attenuation.

I'm no expert on all of the different strains of possible wild yeast and bacteria contaminants. But the first thing I would do is a "bleach bomb" of all equipment, and toss any plastic. Once a wild yeast or bacteria takes hold, it's not easy to get rid of. Many "old time" cider makers use wild yeast to ferment wines and ciders with good results, but they will also go dry. They just don't stop until all of the fermentables are consumed.

That said, what is your FG when you bottle? I'd be curious as to what the SG is after a couple of weeks, to see if there is indeed more fermentation taking place.

 

[JuanMoore]

I have heard of 'gusher infections' from several sources, but I have never seen a specific cause outlined. What strain of bacteria causes it, and why can they suddenly consume sugars that yeast can't consume?

Each yeast strain is only able to consume a certain profile of sugars. A different yeast, or a bacteria, will be able to consume a much different sugar profile. If you add wine or champagne yeast or brett etc to a fully fermented beer, fermentation will restart as the new organisms consume the sugars the original yeast could not.

And why don't they cause off flavors?

Most gusher infections do produce off flavors, but it can sometimes take a couple months for them to build up enough of the off flavor producing compounds to reach human taste thresholds.

Bacteria and yeast don't (to my knowledge) only produce CO2 when they consume sugar.

Correct, they produce all sorts of things in conjunction with CO2. The other byproducts and their relative ratios vary wildly depending on what yeast or bacteria is at work, and what they are eating. They may not produce significant quantities of off tasting byproducs before they finish, or may work slow enough that it takes months for the off flavor producing compounds to reach human taste thresholds.

The yeast pitched (unless it was virtually dead when pitched) will be the dominant strain, and bacteria just can't produce the much CO2 that I'm aware of.

The yeast pitched is most likely the dominant strain during fermentation, but most gusher infections occur during bottling after the yeasts fermentation is complete. Several types of bacteria work very well along side yeast. Brettanomyces is one bacteria that works famously well with brewing yeasts. The ginger beer plant (used to make alcoholic ginger beer) is a gelatanous colony of symbiotic saccharomyces florentinus (brewing yeast) and a lactobacillus (bacteria). It takes very little fermentation of either a yeast or a bacteria to produce more than enough CO2 to create a gusher. Keep in mind how little fermentation it takes to carbonate the beer naturally.

 

[Bheher]

Ok this is tons of info, thanks guys!
Yooper- My SNPA clone finished fermenting at 1.010 just opened a bottle thats about 7 weeks old and starting to gush more every week and its gravity is 1.003 so I guess I can assume something is eating the sugar after I bottle then.
My current process is; fermenting in big coopers plastic jug then racking to a glass carboy. Then I go back to the the coopers jug to bottle. So I am tossing the jug in the corner and fermenting and racking in the glass after i bleach the crap out of it.

 

[Bheher]

Also, now that I am opening beers at 11:30 AM I opened a brown ale that I bottled back in Feb. It finished fermenting at 1.018 (I used too much crystal 120) but now is at 1.012. It does not taste sour or anything. It has dried out a bit I guess, I can't really tell if its drying out from age or bacteria eating the sugars.

 

[JuanMoore]

It has dried out a bit I guess, I can't really tell if its drying out from age or bacteria eating the sugars.

Age doesn't dry a beer out, wild yeast or bacteria do. I'd go through everything that touches the beer after fermentation very thoroughly and replace anything even remotely suspect. Give everything a super thorough cleaning and sanitizing. Any transfer hoses would be #1 on the list to replace. The faucet on your fermenter is a common place for bacteria to hide also. Check for any scratches in anything plastic.