[In The Sand]

I recently purchased a 0.5 micron diffusion stone to use for force carbonating kegs.  I've used it on about 3 batches so far and it works great!  I can carb a beer in 2 days, rather than 2 weeks.  I just use a short piece of 1/4" tubing with the diff stone on one end and shove the other end on the gas in post.  I followed the instructions for the carbonating lid, since it's the same concept.  My question is, why do they suggest starting at 2 psi and gradually raising the pressure to serving pressure?  If it is cold (at serving temp), why not just set at 10-12 psi and leave it? 

The first batch I did according to their directions.  The second batch I was a little more aggressive and started at about 8 psi, then bumped up to serving pressure within 12 hours.  Beer was ready in the same amount of time.  The batch I kegged last night I did the same way.

[AmandaK]

I also do the quicker method with that system. 10 psi the first day, 15 the next and I have well carbonated beer.

[majorvices]

If you have a little headspace in the keg you should be able to carb it in hours. Try this: Put about 8 psi on the top of the keg and the, take off co2 and attach to diffusion stone and put it at 15. The co2 will be forced into the beer due to top pressure and you should get much faster results. You may need to play around with the regulator. Higher than 15 may give you much faster results but watch out for over carbonation.

[Gordonwerks]

This sounds like a great process. Beer "Faster" is a good thing! However, never working with a diffusion stone, I don't quite understand the entire process. Is the CO2 escaping or cycling somehow? I understand the point of the diffusion stone, but once the keg reaches the pressure its regulated for, the CO2 stops entering the keg. Is that the point of starting at a lower PSI? To expose the diffused CO2 in stages?

[AmandaK]

I would imagine that starting at a lower pressure would somehow ensure that more CO2 stays in solution and doesn't escape to the headspace. That could be mitigated by the 8 psi stage mentioned above by majorvices.

[kramerog]

If there is too much pressure, you could blow the stone or hose off.

[bboy9000]

I set the regulator to 40 psi for 36 hours, no stone, and usually get the carbonation close to where I want it.  I have some friends that do 30 psi for 48 hours, sans stone, and they get the same result.  All without another piece of equipment to mess with.