Naturally Carbonating 50L Keg Questions?

[Elvish]

Hey guys I have just put on a batch of an American pale ale which I will be putting into a 50L cub keg. So I have brewed two 23L identical batches that I will be combining and racking into the keg.

1. How long will it roughly take to naturally carbonate a 50L keg of beer using dextrose?

2. Do I need to put CO2 into the keg and burp it to remove oxygen from the airspace above the beer?

3. Can I use normal brewing calculators for larger amounts of beer? I used one and got just under 300g of dextrose for 46L of beer at 18*c.

 

[Jack of all biers]

1. It depends on how much viable yeast is left over, but if it's 'normal' then 2-3 weeks as per bottle conditioning.

2. Can't hurt if you've got CO2, but won't ruin your beer if you don't.

3. Yes. 6.5 gm per litre fits within the medium level of carbonation so should be good for your American PA

 

[Elvish]

Thanks mate!

1. It depends on how much viable yeast is left over, but if it's 'normal' then 2-3 weeks as per bottle conditioning.

2. Can't hurt if you've got CO2, but won't ruin your beer if you don't.

3. Yes. 6.5 gm per litre fits within the medium level of carbonation so should be good for your American PA

 

[peteru]

Assuming that a 50L keg will behave same as a 19L keg, then you seem to have way too much dextrose. I've done a 19L keg of American Pale Ale with 50g of dextrose and some dry hop pellets. It was carbonated at room temperature in about 5 days. After chilling it for 3 days, it was slightly overcarbed. I released all the pressure, let it stand for about 3 hours, then released all pressure again. It was just fine after that.

I did not purge with CO2. My reasoning was that the yeast would chew through any O2 pretty quickly.

So, based on my numbers above, you should be using about half the dextrose that you are planning to use, perhaps less. A week for carbonation at 20C should be enough.

Expect some cloudiness in the beer, until it has been sitting still at serving temperature for at least 5 days, maybe longer, depending on the yeast.