Is my beer infected?

[premington]

Three weeks ago I racked my stout from primary to secondary. I'm very fussy about cleanliness and sanitation and spend more time cleaning than actually working on transferring the beer. Used PBW and StarSan on everything. Anyway...

Moved the stout over, which didn't fill the 5 gallon carboy completely, so there's headspace leftover. The beer didn't fill to the top of the carboy. There's a good surface area exposed to air inside the carboy, which I'm not happy about. I've moved to 6 gallon batches to ensure this doesn't happen again.

I looked at the beer this weekend and see there's about a 1/8" layer of what looks like foam over the top of the beer. It looks exactly like a head. It's very, very fine bubbles, tan colored (the beer is black). It looks exactly like what you see when you pour a stout into a glass--it looks like a beer head.

A few days after racking it to the secondary, I looked and the top of the beer looked clean and clear. This somehow formed over the last 2-1/2 weeks or so. I don't dare take the top off to give it a sniff. This weekend, we'll be bottling it (assuming it's not messed up), so I'll have a chance to make a more thorough check.

But I'm wondering if anyone here has seen anything like this? Maybe the beer kicked up a bit of fermentation after racking? Or maybe some CO2 released while it aged? The area where it's stored warmed up a little (mid 60s F), since the weather warmed up here. Not sure if that would cause it to ferment again.

Any thoughts?

 

[flars]

Your stout may have not been completely fermented before you racked. Take a couple of SG readings before you rack your beers or don't rack to a secondary vessel at all. Some yeasts finish very slowly. I had a porter with a stable SG for 6 days. The porter finished fermenting in the bottles. I was able to save it though with no bottles exploding.

Your stout may be done fermenting. I would recommend a couple of SG readings before bottling.

 

[Revvy]

Your stout may have not been completely fermented before you racked. Take a couple of SG readings before you rack your beers or don't rack to a secondary vessel at all. Some yeasts finish very slowly. I had a porter with a stable SG for 6 days. The porter finished fermenting in the bottles. I was able to save it though with no bottles exploding.

Your stout may be done fermenting. I would recommend a couple of SG readings before bottling.

I agree with Flars. I'm thinking you racked before fermentation was complete, or the yeast had stalled and got woken up when you moved it.

 

[premington]

What's weird is, the beer spent a month in the fermenter before racking. Fermentation appeared to be done. I saw no gravity change or signs of fermentation for a little over two weeks.

Well, this may be good news then? If racking and perhaps the raised temp kicked up some final fermentation, I assume that layer on the top of the beer is actually protecting the brew from oxidation. I don't like the headspace in the carboy, and have no CO2 or nitrogen to sparge it out.

This weekend will be week 8 since pitching the yeast. I can take a gravity reading then, but I'd like to hope after two months, fermentation is over. As I said, we plan to bottle it this Saturday.

 

[Revvy]

Pictures always help in diagnosing these things.

 

[premington]

Okay... Here's a pic of the "sick" stout. I'm thinking it's a newly formed krausen due to refermentation, but thought I'd check with all of you, in case I'm wrong.

 

[flars]

That is krausen. Definitely not an infection.

 

[premington]

That is krausen. Definitely not an infection.

Second person to tell me that. It amazes me... It's been almost two months since I pitched the yeast. Guess it's a learning experience for me. The only thing I can think is racking it stirred things up and perhaps the 5 F temp increase due to warmer weather kicked off more fermentation.

We plan to bottle on Saturday? You think it's safe to do so?

 

[flars]

Second person to tell me that. It amazes me... It's been almost two months since I pitched the yeast. Guess it's a learning experience for me. The only thing I can think is racking it stirred things up and perhaps the 5 F temp increase due to warmer weather kicked off more fermentation.

We plan to bottle on Saturday? You think it's safe to do so?

Might be a good idea to take a SG reading on Saturday instead of bottling. Check again a week later. You have a very slow fermentation finishing up.

I can give you the details on how to release the pressure produced when a fermentation finishes in the bottle if you would need it later.

 

[premington]

Might be a good idea to take a SG reading on Saturday instead of bottling. Check again a week later. You have a very slow fermentation finishing up.

I can give you the details on how to release the pressure produced when a fermentation finishes in the bottle if you would need it later.

Yes... I'm always interested in learning. If you can share info on releasing pressure in the bottle, that would be helpful.

I think I'll take a gravity reading this evening, then compare it to with a reading on Saturday. If it's stable, I'll bottle. If it's not, I'll wait.

We have another ale to bottle on Saturday as well, so if we don't bottle the stout this week, no problem. We'll bottle in a few weeks. With the krausen on top, the beer's well protected and in a nice environment, even with all this headspace. I planned to let it age further, so for the stout, I see no rush to bottle.

 

[premington]

I just had a thought... If the beer developed another krausen in secondary, do I have to wait for the krausen to fall before bottling? Or will it stay at the top even after fermentation is complete?

Tonight I plan to take a gravity reading and taste/smell it. On Saturday, I'll do another gravity reading. If both gravity readings are the same, then I'll probably bottle it.

But should I wait until the krausen falls? Or would it be better to just let it age in the carboy rather than the bottle?

 

[ZmannR2]

Why are you racking to a secondary anyways? I've never rakced to a secondary ever. Less risk of oxydation and infection.

Also, why are you spending so long fermenting? Stouts I guess I can see but most of my beers only spend 2 weeks fermenting before kegging/carbing/bottling

 

[premington]

I wanted to get it off the yeast cake, which also had 24 oz. of spent chocolate and hops. Perhaps it wasn't necessary, but I didn't want to chance having autolysis occur.

I thought fermentation was done, since it had fallen silent for 2-1/2 weeks and the gravity had dropped a good amount. I never expected it to start up again. It tasted plenty dry when I racked it.

 

[Revvy]

Autolysis, in extended primarying has been long proven to be a myth.... it's a product of old thinking from back in the days when yeast was less healthier that it is in the 21st century. Even John Palmer who sparked the Autolysis panic with the first edition of How To Brew admits he was just recycling old ideas without even knowing that people were skipping secondary and opting for extended primaries.


That's a normal karusen BTW.. and yes you let the Krausen fall, and take a gravity reading after it falls.

Remember, you're not in charge of when to do things, like bottling, the yeast are, and they can't read calendars... we don't dictate when we want to do something... we check with them first, we take gravity readings BEFORE we decide to secondary (if we feel we have to) and we don't do it til fermentation is complete... nor do we bottle unless gravity is stable.

That's the nice thing about extended primaries.. most f my beers stay a minimum of a month in primary.. it leaves plenty of time for the yeast to finish, then to actually CLEAN UP the mess it made during fermentation by eating the tings that cause off flavors, then settle and clear. You don't have to worry about bottle bombs or extra krausens, you just let nature take it's course.

 

[premington]

Autolysis, in extended primarying has been long proven to be a myth.... it's a product of old thinking from back in the days when yeast was less healthier that it is in the 21st century. Even John Palmer who sparked the Autolysis panic with the first edition of How To Brew admits he was just recycling old ideas without even knowing that people were skipping secondary and opting for extended primaries.


That's a normal karusen BTW.. and yes you let the Krausen fall, and take a gravity reading after it falls.

Remember, you're not in charge of when to do things, like bottling, the yeast are, and they can't read calendars... we don't dictate when we want to do something... we check with them first, we take gravity readings BEFORE we decide to secondary (if we feel we have to) and we don't do it til fermentation is complete... nor do we bottle unless gravity is stable.

That's the nice thing about extended primaries.. most f my beers stay a minimum of a month in primary.. it leaves plenty of time for the yeast to finish, then to actually CLEAN UP the mess it made during fermentation by eating the tings that cause off flavors, then settle and clear. You don't have to worry about bottle bombs or extra krausens, you just let nature take it's course.

This is great information. I had read previously about autolysis and have been concerned about this. Thanks for clearing this up for me.

If I plan to fine, I'll generally rack to secondary and use gelatin a week before bottling. I have a light ale I racked over last weekend. It's being fined now, then I'll bottle this weekend.

With this stout, I also wanted to separate it from the oil left over from the chocolate. I didn't want to risk that getting in the bottles. So I racked it and left the top out of the secondary (oil rises). I tossed the very top of the beer and the gunk at the bottom. The idea was to have a clean beer at bottling, not one that had yeast, chocolate, and hops on the bottom and a skim of oil on the top.

What was racked over was very clean... no fining necessary, of course, being a rich stout. But now the yeast, as you said, are telling me they're not done. I guess they napped for a while, and I woke them up moving them to a secondary.

I typically will leave the primary alone for a month or so. If the style warrants it, I'll do a diacetyl rest during that time. Either way, I like to give extra time after gravity has settled and the airlock has fallen silent for the yeast to clean up after themselves.

But this batch was a learning experience. I've learned, even after letting it rest and waiting a month+, watching for a low and stable gravity that doesn't change, that the yeast can still decide to kick into action again without warning.

To be honest, I'm in no rush. It's in a stable environment now, so I might just let it sit as it is for another month or so. I would like to think, after three or four months, that fermentation would be complete.

 

[Revvy]

This thread is old, but it's what was the main discussion right after Palmer started back peddaling on the whole autolysis thing. Basically he was hearing more and more about people like me and hundreds and hundreds of brewers online who said, we've left beers for upwards of 6 months with no issues... then he came up with some backpedalling about "weight of beer" in large fermenters, but over the years he's basically came out and said he just repeated things that he "heard" from other brewers without investigating or giving it much thought. Like so much in this hobby, there's a bunch of old "chestnuts" that people believe and pass on without even experience it first hand... and it just gets repeated ad nauseum... and some people stick to their guns bruttally....

It makes sense what you did... If I add fruit and such in primary (and not use a bag) I will rack after a month just to get in away from everything.

I thought maybe you racked it to the cocoa nibs, and was thinking residual sugars might have kicked off another fermentation.

I'm wondering, did you have a hot and cold snap like we have had most of the spring here in Michigan? I'm wondering if you had a drop in ambient temp at some point in your home and the yeast went dormant, then when you racked it, you woke them up? It's happened to me on occasion, by "brew closest" is in a closet that is under a stairwell for the flat above me, and it can range depending on the temp outside anywhere from the low 50's in the winter to probably mid 70's.... and this winter/spring we had a few back and forth days, where I had some fermentation with strong airlock activity on the first warm day stop for the next day when it was cold, and then pick back up the next day when it was hot again.

just a thought.

 

[premington]

Thanks, Revvy, for forwarding the thread and for the advice.

I learn a lot from Palmer and really look up to him (and many others). His online book has been a great resource, but I forget where I read about autolysis. I refer to lots of different sources for information. I'm glad you corrected me though... Makes life easier when I have one less thing to worry about.

My setup sounds similar to yours. The lower level of our home is below grade, so it's always cool down there. The coolest area is a crawl space below the stairs. In the winter, it's in the 50s. Great location for fermenting ales! I put a small space heater under the stairs to regulate winter temps if it gets too cold.

I fermented this stout at around 63 F, but you're right... the temp has risen over the last month. The area under the stairs has risen from ~58F to probably mid-60s or so. I used the heater to keep temps stable at around 63 F, then raised the temp a bit to help finish things off. Then I turned off the heater. It slowly dropped back down to the low 60s and stayed there. The drop was gradual, so I don't understand why they went dormant.

The recent rise in temp I'm sure had something to do with it restarting, but this rise was only a few degrees (~66 F). Perhaps racking it also stimulated fermentation. I don't know enough about yeast to know how movement and change of environment (ignoring temp for the moment) can affect yeast.

Is it possible that all the other "stuff" in the primary was contributing to it going dormant? Perhaps transferring it created a more hospitable environment for them to complete their work?

Or perhaps it's all about a mildly raised temp?