There are 2 ways I’m aware of to Force Carbonate.
1st is the method I use most often. I think I read somewhere that you stand less of a chance for the beer to get stale, the drinkable
time frame of the beer last longer.
First, put the keg cold in the fridge not carbonated. Cold beer with hold more C02 than warm beer will.
After kegging the beer, connect the tank and regulator to the beer turn the regulator up to 30 p.s.i. Purge the air in the keg so only
C02 is in the keg. Leave for at least 24 hours, release the pressure and set the the regular and tank on to hit the beer with 10 p.s.i. of C02.
This method will be less physical work than shaking 5 gallons of beer, and it does take a day or two of leaving the beer at a high p.s.i.
Pro: Less likely for beer to be stale or oxygenated
Con: Takes a few days to get carbonated, could drink flat beer.
2nd method is crank and shake.
After kegging beer connect the tank and regulator. Turn pressure on the regulator up to 30 p.s.i. Bleed off the oxygen, by opening the
keg valve, so only C02 is left in the keg. For 60 seconds shake the keg from side to side.
This will instantly give you carbonated beer, but I’ve heard that the beer stands a chance of going stale faster. Before serving make sure to release keg pressure down to a serving level of 8 p.s.i to 10 p.s.i.
Pro: Instantly carbonated beer
Con: Higher chance of beer going stale. Beer can get over carbonated.
There are pros and cons to both methods. I guess it depends on the situation, for example if you need carbonated beer now for a party.
Normally when I brew I’m the only one drinking most of the keg. I want the keg to last as long as possible. It’s common for a keg of homebrew to last me 4 to 6 months. I use the first method.
Recently I brewed a beano beer. I thought the beer might have been infected, but I kegged it anyway. It’s only 2.5 gallons. I did the crank and shake to get instant carbonation. Beano beer is not infected, it’s a light beer with no body and no hops. I don’t care how long I have this beer on tap, I’m already planning my next brew.