Keg carbonation question

I am new to kegging and just finished force carbing my first batch. So a week ago, I siphoned my beer to the keg, forced out the air with a few bursts of co2, shook it a little, then set the pressure to 25 psi and let it sit that way for a week. Last night I lowered the pressure to 12 psi and poured my first glass (well I did steal a few small tastings while it was force carbing). It was very foamy but when the foam settled out, there was hardly any co2 absorbed in the beer itself, but the head lasted nicely. Is this because, it is not carbonated enough and the co2 is not absorbed into the beer or it is too carbonated, causing the foam which in turn causes the co2 in the beer to dissipate quickly or it will just take another few days or so to settle down from the pressure being up so high?

well, first off, 25 psi for a week is too much, especially if you shook it also. you can set it at like 30 overnight, at most for 48 hrs, but then back it down to 12 to sit for the rest of the week. i'm guessing that it was too carbonated, but there should have been some residual co2 in the beer also. how long are your lines?

what was the temperature where you stored for a week? If it was over 60 degrees then 25lbs shouldn't have overcarbed in just one week.... at 60 deg I'd say about 22 lbs for 2 weeks...

shook it 'a little'? there again unless the temp was very low this may have done almost nothing.

When you sample you can avoid the foam by venting all the co2 from the keg first then setting the pressure to about 8lbs, increase as necessary even while you pour. I will never overcarb because I am sampling very often.....

Yea the line is about 4 feet with a thumb tap, just the piece that came with the keg kit. I just basically did what my lhbs told me to do. The beer was cold less than 50 when I bottled it because it was a lager and then the keg went right into a 40 degree refrig. There is a small amount of co2 in the beer when the foam subsides but it's not jumping off the bottom of glass If you know what I mean, but I do think that it is overcarbed. The best thing to do would be to purge all the co2 then raise it to about 8 psi then it should settle out over time, hopefully?

At 40F assuming you want 2.5 volumes CO2 you should be at about 12 psi. Your LHBS probably told you to set it at 25-30 psi for a day or two max and then drop pressure to serving/carb pressure. The high psi initially will help speed up the process but you should definitely not leave it at 25 psi for a week.

my guess is that your line is too short. i use 6 ft lines and serve around 14 psi. I would try to lower your serving pressure, I think the line is just causing all the co2 to come out of suspension before it hits the glass.

At 25 psi for a week at fridge temps, it's WAY overcarbed. What happens is all of that foam "knocks out" the co2 out of the beer, and into foaming.

I'd turn off the gas, and pull the pressure relief valve a couple times per day. (You can still sample beer, of course!) After about three days, reset at 12 psi and see it's improved.

There are lots of ways to do things, but shaking the keg is never a good idea, in my opinion, especially at over 12 psi. It'll carb up fast, yes, but it'll be overcarbed.

My two favorite ways of carbing (in order):
1. Put the keg in the kegerator with the other kegs and keep all of them at 12 psi all the time. Perfectly carbed beer in 7-10 days that stays that way until the kegs are gone.

2. In a hurry- set the keg in the kegerator at 30 psi for 36 hours. Purge, and reset to 12 psi. Perfectly carbed beer in 5 days, but sometimes a bit overcarbed.

Yes, you're overcarbed and the way to reduce carbonation is to vent the pressure in the headspace once every hour or so for a day or two. Do not reconnect the gas in between otherwise you're only delaying the decarbonation process.

Thanks for alll your help guys! Failure on my part but at least it's fixable!