Oxygen contamination

Hi folks,

I've been trying to find info online for this specific problem but have so far come up empty. Figured I'd give up and ask the experts. I brewed a 2.5 gallon batch (don't have the necessary equipment yet) and threw it in a 6 gallon bucket fermenter. I've read about the fermentation producing a nice blanket of co2 to protect from oxidation. I want to take the lid off to check the gravity/taste test but I'm afraid if the beer isn't ready and I have to put the lid back on for several days I'll cause oxidation. There's a lot of airspace in this bucket...

The beer's been in the fermenter for 10 days (pale ale)

Thanks all,

Mike

CO2 is heavier than the air in your house. It will stay in there as long as you don't agitate anything too much.

I accidentally left my bucket in secondary fermentation open on one side for 2 weeks. Beer still tasted amazing.

Don't be too concerned with it, I'm sure you'll be fine.

I wouldn't worry. As Kharper6 said if you dont agitate it too much you should be fine. However if the yeast are still fermenting they'll produce more C02, and then the wort itself will naturally off-gas some of the dissolved C02 and they'll fill the headspace in the fermenter.

Ok - thanks for your reply

The amount of CO2 produced varries with the amount of wort, the OG, etc. HOWEVER as a rough number, a typlical 1.040 beer will produce about 60 gallons of CO2 per gallon of beer. (based on standard air density). This means with most normal brewing equipment, you never have to worry about not displacing the air in the fermentor.

(*NOTE - I know it get's fuzzy around the edges because of the randomness of molecules, but, for all practicle purposes...)

sankenship said:

Hi folks,

I want to take the lid off to check the gravity/taste test but I'm afraid if the beer isn't ready and I have to put the lid back on for several days I'll cause oxidation. There's a lot of airspace in this bucket...

Mike

Click to expand...

Just loosen the lid and slide it back enough to take a sample and slide it back onto the bucket. Yanking it off and waving it around (LOL) like a fan could blow out a lot of CO2, but I am sure you have no intentions of doing that.
No need to totally remove it if you are worried about wafting out all the CO2.

bosco

I sanitise my thief and poke it down the airlock hole to collect a few drips for the refractometer , tested.
Lid off won't cause oxidation, it's just an opportunity to let unwanted in until it's absolutely necessary .

Just leave it alone for 14 days and then check the gravity. It'll be done by then. Plus wort tastes like crap. Especially wort with yeast still working.

Gary