Bottle carbonation - yeast raft or infection?

[WeatherWithYou]

Hi all,

I just bottled my first brew (at least since one I did for Uni back in 2011), and less than 24 hours later I've got a bunch of gunk at the top of each bottle. Not ideal, but I can't tell if this is more likely to be yeast rafts or infection.

This is the relevant brewing info:

It's a kit brew using pre-hopped wort, only thing I added was boiling water, tap water, and some steeped finishing hops. Fermentation went OK, gravity levelled out at 1.010, which is a bit high but I don't think I was using the healthiest yeast so attenuation probably wasn't fantastic. Fermentation temp was typically around 24C, but may have gone up as high as 26C at times, as I don't really have temperature control options (I'm in an apartment with very little space). I neglected to take an OG reading. Fearing a stuck fermentation, I gave the fermenter a couple of swirls 24 hours apart, but nothing changed gravity-wise. The yeast, however, completely refused to settle, terrible flocculation and an extremely hazy beer.

I decided to do a single bottle to check if this was going to end up being bottle bombs, and within about 5 days it was done, which probably isn't surprising given how much yeast was floating in the beer, but it seemed to level out and not explode. It did warp the bottom of the PET bottle a bit, but I left it for a couple of days and it got no worse, the bottle still had a little bit of give, so it wasn't bursting at the seems. I chilled it and took it to a party and it was perfectly carbonated, but very, very green flavour-wise.

I decided to dry hop with about 25g Cascade hops - pellets straight into the fermenter. This did not improve the haze/murkiness situation, I should have used a sock, but I could not be bothered doing up sanitiser for a single hop sock. Lesson learned I guess.

Anyway, left it to dry hop for a few days, the flavour and aroma greatly improved over this time. Two nights ago, I grabbed some finings in an attempt to clear up the beer. When dissolving I thought I set the kettle to 80 degrees but may have forgotten to, so I'm not sure if I used very hot or boiling water, in case that's relevant.

Then last night, I bottled the rest of the beer because I had some time and was, frankly, impatient. The finings didn't do much, the first 5 bottles or so I put a hop sock over the bottling wand to filter out the bigger particles, after which point it cleared a bit but was still full of yeast in suspension. There was no hint of infection in the beer - in fact it was tasting way better than I had dared to hope after earlier taste tests.

This morning, there were patches of gunk already formed, and they've gotten a bit larger over the course or the day. It's about 28C indoors today, but the bottles are sitting on a cooler tile floor which I am hoping is keeping them down to around 25-26C. I have attached a photo.

So, given the above information, have I managed to accidentally infect every bottle, or is this more likely down to a very low-flocculation yeast creating yeast rafts? I will do my own taste test of one bottle in a few days, but any insight in the meantime would be greatly appreciated!

Thanks in advance

 

[Vini2ton]

Invert one a few times and put it in the fridge. See if all that stuff drops to the bottom. You won't have to worry about being maimed by a bottle-bomb as they're PET. Drink some, if it tastes like infected arse-juice, you can give it to people you dont like. My guess is its finings residue. Or....covid froth.

 

[WeatherWithYou]

Invert one a few times and put it in the fridge. See if all that stuff drops to the bottom. You won't have to worry about being maimed by a bottle-bomb as they're PET. Drink some, if it tastes like infected arse-juice, you can give it to people you dont like. My guess is its finings residue. Or....covid froth.

Is it worth waiting a few days first? Or would it be worthwhile now?

 

[kadmium]

I would wait, it may be yeast re fermenting in the bottle (you added priming sugar right?)

Unlikely you infected all the bottled and they all got infected so fast. Possible but not likely.

Typically it takes well over a week to floculate the yeast out, and a good cold crash.

Bottle conditioning takes 3 weeks on average to be drinkable.

26c is way too high for fermenting, try a fan blowing air over the fermenter with a wet towel draped over it if possible.

 

[MHB]

I'll take a punt on infected.
True its unlikely that every bottle was infected, much more likely that the brew was. Going back to your post, why would you think your yeast wasn't the healthiest?
I suspect there might be a bit more of a story there, so spill it, if you want people to take a stab at an answer. What sort of yeast was it, was it cropped and reused, fresh?
Mind you if you ever have even a moments doubt about your yeast, change it to something you are sure of.
The old "we make wort, yeast makes beer" is very true.
Mark

 

[WeatherWithYou]

I'll take a punt on infected.
True its unlikely that every bottle was infected, much more likely that the brew was. Going back to your post, why would you think your yeast wasn't the healthiest?
I suspect there might be a bit more of a story there, so spill it, if you want people to take a stab at an answer. What sort of yeast was it, was it cropped and reused, fresh?
Mind you if you ever have even a moments doubt about your yeast, change it to something you are sure of.
The old "we make wort, yeast makes beer" is very true.
Mark

I suspect the yeast wasn't the healthiest because it was from a non-descript silver packet that came with a Morgan's Blue Mountain Lager tin, whose age and condition I have absolutely no idea of, and I got lower attenuation than I was expecting.

No signs of any infection while fermenting, and by bottling time it was tasting quite good. It's really just the lower attenuation and complete lack of flocculation that has given me some concern, until this point.

 

[MHB]

Would agree that it is a pretty massive under pitch. If I recall correctly BML has a mix of Mauri 497Y and something very like Windsor. Unhealthy probably isn't the best description, inadequate would be better.
I have never seen it behave like yours, so I suspect there is something else living in there. It's probably rare that any home brew has a pure yeast strain and nothing else living in it. Fortunately most bacteria don't do too well in the anaerobic, low pH, hoppy, alcoholic conditions of a beer. There are some that do and a bunch of wild yeast that feel right at home.
There is a fair chance that it wont do much harm, conversely there is a fair chance that it will get worse. If the beer is drinkable, get it cold, keep it cold and drink it as soon as you can.
Probably worth getting some better/bigger packets of yeast, in the fridge and they will keep for years. Be extra careful with your cleaning and sterilising, I mean go really over the top especially as your fermenter may well be infected.
No fun when it happens but infections are often part of the cost of doing business. Not having decent temperature control wont help. A secondhand bar fridge, a fan and a temperature controller will make brewing in summer much more rewarding.
Mark

 

[An Ankoù]

Loosen the top on one of the bottles and gently sqeeze. What does itr smell like?
The great thing about using PETs is that you don't leave any headspace: fill them like you have, put the lid on loosely and then squeeze all the air out before cramping down the lid. Reduces oxidation and if you've got acetobacter in there, it'll stop it spoiling your beer too much.
You can't tell from a photo put it doesn't look to me like a mould or bacterial culture.

 

[WeatherWithYou]

Would agree that it is a pretty massive under pitch. If I recall correctly BML has a mix of Mauri 497Y and something very like Windsor. Unhealthy probably isn't the best description, inadequate would be better.
I have never seen it behave like yours, so I suspect there is something else living in there. It's probably rare that any home brew has a pure yeast strain and nothing else living in it. Fortunately most bacteria don't do too well in the anaerobic, low pH, hoppy, alcoholic conditions of a beer. There are some that do and a bunch of wild yeast that feel right at home.
There is a fair chance that it wont do much harm, conversely there is a fair chance that it will get worse. If the beer is drinkable, get it cold, keep it cold and drink it as soon as you can.
Probably worth getting some better/bigger packets of yeast, in the fridge and they will keep for years. Be extra careful with your cleaning and sterilising, I mean go really over the top especially as your fermenter may well be infected.
No fun when it happens but infections are often part of the cost of doing business. Not having decent temperature control wont help. A secondhand bar fridge, a fan and a temperature controller will make brewing in summer much more rewarding.
Mark

It fermented pretty quick! Got down to 1.010 in about 2-3 days. I wouldn't have thought an underpitch would do that?

In any case, I've picked up some Voss Kveik for summer brewing so temp control is less of an issue. I will eventually invest in some temperature control but I'm seeing what I can achieve without it first.

 

[hotwaterpls]

1.010 is about as far as most 'standard' beers go, particularly kit beers - so attenuation is fine there. Won't see much below that without enzymes or particular yeasts (e.g. saison) which can break down sugar chains and chew through more than other yeasts.

Underpitched yeast will often still do the job, and do it quickly at higher temps - it's more the potential for off flavours in the beer (esters from the yeast at higher temp, also depending how long you leave it once fermentation is finished to clean up any diacetyl or similar). A 'healthy' (or 'adequate') pitch of yeast should produce something cleaner at the end of the day (under ideal conditions).

Finings may not do much if it's not chilled (e.g. gelatin finings work better around cold crash temps) and probably take more than 24 hours to clear.

Assuming you sanitised the hop sock over the bottling wand, and all the bottles too?

As others suggested, let them carb, chill one down for a day or two and see how it tastes.

 

[WeatherWithYou]

1.010 is about as far as most 'standard' beers go, particularly kit beers - so attenuation is fine there. Won't see much below that without enzymes or particular yeasts (e.g. saison) which can break down sugar chains and chew through more than other yeasts.

Underpitched yeast will often still do the job, and do it quickly at higher temps - it's more the potential for off flavours in the beer (esters from the yeast at higher temp, also depending how long you leave it once fermentation is finished to clean up any diacetyl or similar). A 'healthy' (or 'adequate') pitch of yeast should produce something cleaner at the end of the day (under ideal conditions).

Finings may not do much if it's not chilled (e.g. gelatin finings work better around cold crash temps) and probably take more than 24 hours to clear.

Assuming you sanitised the hop sock over the bottling wand, and all the bottles too?

As others suggested, let them carb, chill one down for a day or two and see how it tastes.

I did get a few not fantastic flavours and aromas early, mostly astringent and plasticky, which I assumed was chlorophenol and down to Canberra's somewhat highly chlorinated water. That's why I decided to dry hop. Between that and letting it sit for about 10 days the off flavours are no longer noticeable, and none of those flavours were ever sour or funky (or worse), more just what you expect from mediocre homebrew.

I did sanitise everything. The only thing I didn't sanitise was a clean glass I poured a small sample into halfway through bottling to check clarity. Technically it briefly came into contact with the bottling wand, so there's a small chance of infection of subsequent bottles there, however the bottles I did up before that also have the gunk so that doesn't really explain it.

Anyway, I'll chuck one or two in the fridge Friday night and see how they look and taste Sunday arvo.

 

[Vini2ton]

So I've go to wait until sunday? Tip one upside down and put it in the fridge tonight. I bet that stuff drops down when chilled. Why I'm so curious is that I've never seen anything like that in bottled beer.

 

[WeatherWithYou]

So I've go to wait until sunday? Tip one upside down and put it in the fridge tonight. I bet that stuff drops down when chilled. Why I'm so curious is that I've never seen anything like that in bottled beer.

Way ahead of you! Decided to do it earlier today.

It's far from crystal clear but much better than my first test bottle.

Head is great, but carbonation isn't quite there - it's only been a couple of days! But definitely feels a touch flat.

Flavour wise, it's... fine. Better than VB! Some slightly off yeasty flavours, but can't detect anything I'd put down to infection at this stage.

I'm thinking I'll let everything carbonate for another few days, keeping an eye on if any more pellicle-like formations appear. If they do, I'll try to chuck it all in the fridge as fast as I can to stop the spread.

But as it stands, the beer is perfectly drinkable, if not something I'm particularly proud of.

 

[kadmium]

Way ahead of you! Decided to do it earlier today.

View attachment 119822

It's far from crystal clear but much better than my first test bottle.

Head is great, but carbonation isn't quite there - it's only been a couple of days! But definitely feels a touch flat.

Flavour wise, it's... fine. Better than VB! Some slightly off yeasty flavours, but can't detect anything I'd put down to infection at this stage.

I'm thinking I'll let everything carbonate for another few days, keeping an eye on if any more pellicle-like formations appear. If they do, I'll try to chuck it all in the fridge as fast as I can to stop the spread.

But as it stands, the beer is perfectly drinkable, if not something I'm particularly proud of.

When I bottled I found best carbonation to be at 3 weeks.

Also, it's extremely unlikely you will harm yourself drinking "infected beer" unless you have visible mould growth. I get pellicles all the time on mead, I just poke em down and hope for the best.

Now when I cure bacon, I always worry about that tastless, odourless botulism. Mmmmmm

 

[WeatherWithYou]

When I bottled I found best carbonation to be at 3 weeks.

Also, it's extremely unlikely you will harm yourself drinking "infected beer" unless you have visible mould growth. I get pellicles all the time on mead, I just poke em down and hope for the best.

Now when I cure bacon, I always worry about that tastless, odourless botulism. Mmmmmm

Oh yeah I know it's not going to do me any harm, I just want it to stay drinkable.

And yeah, while I might have another bottle or two over the next week just to track how it's developing, I know it will be at it's best in at least 2-3. Provided there isn't a growing infection of course!

 

[WeatherWithYou]

Update on this for anybody interested - tasted another bottle and no sign of infection. The beer has some minor off flavours probably due to fermenting a bit too warm, but it's perfectly drinkable and the haze is starting to drop.

I've put my second batch on and it's also tasting fine and is ready to bottle. So all in all, most likely just a mini-krausen.

 

[Vini2ton]

So did the stuff at the top settle to the bottom of the bottle after chilling? Like alot of us, looking for strange stuff can help us in the future. The truth is out there Scully.

 

[WeatherWithYou]

So did the stuff at the top settle to the bottom of the bottle after chilling? Like alot of us, looking for strange stuff can help us in the future. The truth is out there Scully.

Yeah it dropped! I did gently invert each bottle, but it stayed down and didn't get any worse, and the beers have mostly cleared of haze now without any chilling.

 

[MaggieO]

Seems like a lot of headspace in those bottles. Might want to fill them fuller next time.

 

[Klosey]

From the looks of your bottles on your original post it looks as though perhaps too much oxygen in your bottles and the yeast is still working. 3 things I try to do in every batch I brew. 1. Sanitise. 2. Use high quality yeast. Often discard the yeast that comes with extract kits. 3. Keep the brewing temperature constant.
The yeast that comes with Morgan’s Blue Mountain lager is not a lager yeast but rather an ale yeast so you can brew it at higher temps but in reality a fermentation fridge with a temperature controller should be a priority to give constant great results. I double my yeast when doing lagers but have never found under pitching a problem when brewing ales. Cold crashing works well with both lager and ales and I do a diacetyl rest on both types of brews.