possible infection

[paulg]

Today after 12 days in the fermenter I looked inside to dry hop the beer and found a whitish scum starting to form on top of the beer.
some background
this brew is 25 litres in a 50 litre fermenter,the lid is not a clip on type one so not 100% airtight.
After a week I took a hydrometer reading via the tap ,1.020 sg
I used wlp002 yeast so decided to rouse it using a paddle sterilised with starsan ,no sign of scum
2 days later hydro reading 1.016 roused again,today hydro still 1.016 (beersmith had predicted fg 1.014 )so planned to dryhop and cool for a few days before casking.

so do people think this is acetobachter infection? (spelling?)
the beer tastes fine no vinegar
is it possible that as there is only 25 litres there massive head space in the fermenter by rousing the yeast I have disturbed any co2 covering the beer and this has caused the problem
or have I been lazy in my sanitation somewhere ,I realise that this is the first time I have used an immersion chiller instead of a plate chiller and didnt spray the boiler tap with starsan.with the plate chiller I used to recirculate for 10 minute during the boil to sterilise

[NobbyIPA]

is it that your fermenter is not sealed??

i've heard that fermenting in open fermenters in certain yeasts can cause a whitish film on top of the brew after the ferment
try to omit the white scum when transferring it to your bottling bucket or keg what ever

cover your ferments with something solid. You may not have to "seal" them up with an airlock, but if you're fermenting with an open or none air tight fermenter, i would change it so as to be air tight with a blow off tube

This may solve your problem.

maybe it is the wlp002 that acts this way if not sealed????
not used it myself but sounds like it?
and if it smells ok it should be ok imo

[paulg]

yeah the fermenter has a lid held on by 4 lock down clips and a foam strip similar to draft excluder on it.I removed the foam so there is a small air gap between lid and pot ie the airlock does not bubble.
I have just ordered a sstech bucket from rob the malt miller ,this has a silicone seal on the lid and is more appropriate for 23-25 litre brews and will only use the 50 litre one for 45-50- litre brews

[Matt12398]

Yeasts, moulds and bacteria can't travel uphill i.e. they can't crawl inside your fermenter through a gap so unless they are caught in an upward air current because you're blowing stuff around then being airtight isn't essential to prevent an infection.

If it's still at 1.016 it doesn't sound like an infection. I sometimes get some yeasty flocs floating around which have made wonder what they were. If it tastes ok I think you're fine.

[paulg]

agreed
but my fermentation fridge is a coca cola style one with a fan permanently running so if there was bacteria in the fridge then maybe when removing the lid to rouse the yeast.
I am going to try to disinfect the fridge but it is difficult to get to the fan and condensor assembly so a sealed fermenter may be better.
I brewed for several years with a plastic fermentation bucket then upgraded ? to a stainless 50 litre bucket but often only have 23 -25 litres in it.
I use plastic pins so brew in multiples of 20.5 litres plus some for fermenter loss
I usually leave the beer in the fermenter for 14 days allowing it to fully ferment out maybe I should rack to the cask a bit earlier and try to get to the 2 gravity points before FG

[Matt12398]

That's fair enough then. I'm getting a Brew Bucket as well because they seem to be a great fermenter.

[Eric]

agreed
but my fermentation fridge is a coca cola style one with a fan permanently running ...................

I usually leave the beer in the fermenter for 14 days allowing it to fully ferment out maybe I should rack to the cask a bit earlier and try to get to the 2 gravity points before FG

In comparison to many other yeasts, WLP002 drops like a stone and sets like cement while it's finishing. I'd not give up on this for there's a possibility it may be just the scavenging activities of a few youngsters. In future you must consider a shorter primary fermentation period. Are all commercial beers that spend less than 14 days in primary that bad?

[Matt12398]

Are all commercial beers that spend less than 14 days in primary that bad?

That is a reasonable point but they also probably pitch at the correct pitching rate, oxygenate their wort and probably know how their yeast behaves and how to treat it.

[paulg]

eric
I have always left the beer for 14 days to allow the yeast to clear up.
In your opinion what is a reasonable time before racking to cask, bearing in mind I normally ferment then cold crash for 24 hours and rack to cask with priming sugars and finings.I then store in fermentation fridge for 1 week then drop temperature to 12 degrees for 3 weeks minimum.
I dont like to keep opening the fermenter,that is why I leave for 2 weeks but with the new one coming I can take a sample from the racking port without opening the lid so can more easily monitor the gravity.

[legion]

I have had 4 similar infections this year with fermenters with slightly open lids

Two have gone sour, two have tasted fine. I would recommend, bottle / kegging it immediately and start drinking it tomorrow. If it is going to turn sour then it will likely taste better now than it will in a couple of weeks time. However you may get lucky and it doesn't have any affect on flavor.

Alternatively you pasteurize it and then force carb or add new yeast.

[Eric]

Most homebrewed beers spend 2 weeks in the FV. I don't leave mine that long. Earlier this evening I had a pint that was just under 20 days since the yeast was pitched, and while I expect it to improve still, if it had spent 14 of those days in the FV I wouldn't have bothered to pour that drink.
There are many aspects to consider and every brewer does similar things in their individual way. I mash for 90 minutes and recycle until the wort clears. I boil vigorously for at least 90 minutes, chill quickly in the kettle and let it settle to be crystal clear before it goes into the FV. Time in there varies depending upon the yeast used, but with no trub, WLP002 will normally be on its way to the bottom after 3 days and the beer in the cask within seven. I do not normally use finings and have no phobia of diacetyl spoiling every brew.
Living on the north east coast it's virtually always cool on an evening such that I don't need refigeration, just an open door or use a side path overnight. That also means the beer doesn't get chilled for drinking, so I have no concern about making a beer that is prone to throw a chill haze.
While it's not a problem for me now, there was a time I didn't brew in summer because of fear of infection. I can't tell how I'd get on brewing in your climate, but I'd be inclined to get the beer sealed away as quickly as possible.

[bob3000]

My suspicion would be the infection happened during the rousing. It's a big risk taking of the the lid and stirring it about. Especially in your climate.

[paulg]

yes I suspect it was when rousing ,I think in future I will avoid this and just hope if I use wlp002 it doesnt drop out and stop working.My next brew will use wlp 022 yeast which I have found is a good worker and doesnt need rousing

[sbond10]

I now use clean film lid on clean film around the top seems to work