Infected? not infected?

[eryk4381]

I have a mystery beer I made from grains I had leftover and its down to 1.008 for FG but I left it a few days before kegging and now I have this odd bubbleness on top.

 

[Brauer]

I have a mystery beer I made from grains I had leftover and its down to 1.008 for FG but I left it a few days before kegging and now I have this odd bubbleness on top.

Looks like you just made your first sour. Don't pitch it. Wait 6 months and give it a taste

 

[jtratcliff]

Rack from underneath the nasty and drink it quickly...

 

[eryk4381]

so which is it.. Wait or rack it? LOL

 

[day_trippr]

That's definitely got something other than yeast working.

- If you like sours, let it ride.

- If you keg and don't like sours, rack now, chill, force carb and consume with a degree of haste.

- If you bottle and don't like sours, rack now, and make sure you do the warm conditioning under/behind a blast screen...

Cheers!

 

[ArkhamAsylum]

Time heals all wounds, and rescues some beers. My vote is to rack into a fresh vessel and hope the residual yeast can do some clean-up.

And dry-hop the crap out of it, regardless of style.

 

[eryk4381]

That's definitely got something other than yeast working.

- If you like sours, let it ride.

- If you keg and don't like sours, rack now, chill, force carb and consume with a degree of haste.

- If you bottle and don't like sours, rack now, and make sure you do the warm conditioning under/behind a blast screen...

Cheers!

I'm assuming by all these posts that it seems to be infected with lacto?
Would this be possible at fermentation of 62 degrees? I never had this above 64 And it finished fermenting and then formed these bubbles.

 

[RM-MN]

Lacto can ferment when it is cool but it requires oxygen which should be absent in the primary as the yeast would have consumed what was dissolved in the beer and then produced enough CO2 to push the rest of it out. If you rack to secondary the CO2 is lost in the process and you will have only the CO2 dissolved in the beer to push out the oxygen which is why many of us either recommend that you do not rack to secondary or if you do we would recommend that you rack to a smaller vessel so it gets filled all the way up to the neck leaving only a little air space which can then be filled by the outgassing CO2 from the beer.

Lactic acid bacteria are Gram-positive, non–spore-forming rods (or cocci), and they are obligate fermenters. An obligate fermenter is a microorganism that must ferment a carbohydrate source. They do not grow aerobically. Lactic acid bacteria include Lactobacilli and Pediococci.

Sourced from an article posted in Morebeer.

Brewing with Lactic Acid Bacteria

by Dr. Brian A. Nummer

 

[Calder]

Lacto can ferment when it is cool but it requires oxygen which should be absent in the primary as the yeast would have consumed what was dissolved in the beer and then produced enough CO2 to push the rest of it out.

Even the quote you use says it doesn't grow aerobically. Lacto prefers to be without O2.

That doesn't look like Lacto to me. It could be, but I would go for some kind of Brett if I were to guess.

Advice that has been given is good:

- Taste it, if OK decide what to do. If bad; dump.

- Either continue to ferment for 6 to 12 months, or keg, cool, and drink.

 

[RM-MN]

Even the quote you use says it doesn't grow aerobically. Lacto prefers to be without O2.

That doesn't look like Lacto to me. It could be, but I would go for some kind of Brett if I were to guess.

Advice that has been given is good:

- Taste it, if OK decide what to do. If bad; dump.

- Either continue to ferment for 6 to 12 months, or keg, cool, and drink.

Lacto may prefer low levels of O2 but according to that study it does require some. I wasn't trying to identify the infection as lacto but was answering the question directly above my answer.

 

[Calder]

Lacto may prefer low levels of O2 but according to that study it does require some. I wasn't trying to identify the infection as lacto but was answering the question directly above my answer.

All I was doing was pointing out an inconsistency in your post, I was not really commenting on the content:

Your post:

"Lacto can ferment when it is cool but it requires oxygen"

Your reference:

"Lactic acid bacteria ........ They do not grow aerobically."

 

[RM-MN]

All I was doing was pointing out an inconsistency in your post, I was not really commenting on the content:

Your post:

"Lacto can ferment when it is cool but it requires oxygen"

Your reference:

"Lactic acid bacteria ........ They do not grow aerobically."

That article and the whole subject of lactobacillus is confusing because the lactobacillus doesn't utilize oxygen in its reproduction but it does require at least a small amount. Reference this article from the Food and Agriculture Organization, chapter 5 where I found this:

Despite their complexity, the whole basis of lactic acid fermentation centres on the ability of lactic acid bacteria to produce acid, which then inhibits the growth of other non-desirable organisms. All lactic acid producers are micro-aerophilic, that is they require small amounts of oxygen to function. Species of the genera Streptococcus and Leuconostoc produce the least acid. Next are the heterofermentative species of Lactobacillus which produce intermediate amounts of acid, followed by the Pediococcus and lastly the homofermenters of the Lactobacillus species, which produce the most acid. Homofermenters, convert sugars primarily to lactic acid, while heterofermenters produce about 50% lactic acid plus 25% acetic acid and ethyl alcohol and 25% carbon dioxide. These other compounds are important as they impart particular tastes and aromas to the final product. The heterofermentative lactobacilli produce mannitol and some species also produce dextran.

Now, both those articles I quoted seem to be peer reviewed but they say opposite things, one saying that lacto doesn't require any oxygen, the other saying it cannot function without at least some. Which is correct?

I've found other articles about lacto, one of which says that the products of lacto infections include alcohol and CO2 while the other says that lacto produced no CO2. Am I confused? For sure. Are the authors of the articles confused? It would seem so.

It does seem that the presence of CO2 dissolved in the beer restricts the growth of lactobacillus but the link to how or even whether that is the factor in beer is very tenuous. Maybe somewhere someone has studied it but finding the info is difficult.

 

[GHBWNY]

Even the quote you use says it doesn't grow aerobically. Lacto prefers to be without O2.

That doesn't look like Lacto to me. It could be, but I would go for some kind of Brett if I were to guess.

Advice that has been given is good:

- Taste it, if OK decide what to do. If bad; dump.

- Either continue to ferment for 6 to 12 months, or keg, cool, and drink.

Agree. Or maybe taste and if good, split to two smaller secondaries. Use one fairly soon, leave the other for future use.

 

[Calder]

I've found other articles about lacto, one of which says that the products of lacto infections include alcohol and CO2 while the other says that lacto produced no CO2. Am I confused? For sure. Are the authors of the articles confused? It would seem so.

There are two main types of lacto families (probably more for all I know). One is Homofermentative, which produces 2 molecules of lactic acid from one molecule of sugar and no CO2. The other is Heterofermentative, which produces one molecule of lacto, one molecule of alcohol, and some CO2 from one molecule of sugar. I'm sure my chemistry is not completely correct, but one type produces alcohol along with lactic acid, while the other only produces lactic acid

It does seem that the presence of CO2 dissolved in the beer restricts the growth of lactobacillus but the link to how or even whether that is the factor in beer is very tenuous. Maybe somewhere someone has studied it but finding the info is difficult.

Never heard of CO2 being a problem. I know alcohol inhibits lactobacillius.