I put my keg in the fridge on a Friday night and put the CO2 at about 10 psi. I tried the beer last night and it was not even close. I realize that it should probably take longer to carbonate if the psi is that low, but I am getting impatient. So last night I pulled the keg out, turned the pressure to 30 and realized that the lid was not completely sealed. I pulled the lid, reajusted it and got a good seal. Then I tried to force carbonate. I shook the keg for about 15 minutes then tried it again. It was still not carbonated. The beer tasted great when I kegged it, but now it is very sweet tasting and does not seem to have any carbonation. What am I doing wrong. I wasted half of a batch of beer last time and I really don't want to waste another. Any suggestions?