[DrewG]

Brewed a best bitter and didn't quite get the hop flavor I was after (shooting for something like Goose Island's Honkers Ale with Styrian Goldings) and I thought I'd throw an ounce, maybe an ounce and half in the keg for dry hopping. I've never dry hopped in the keg and the beer is already carbonated. Am I going to run into any issues if I do? Foaming perhaps? I was thinking I'd let it sit 4 days or so and then bottle it.

[jeffy]

I do this frequently by suspending a muslin back in the keg by a piece of unflavored dental floss.

[DrewG]

How are you sanitizing the bag? Boiling, starsan? Or is it a non-issue?

[kylekohlmorgen]

RDWHAHB.

No problem in hopping past-carbonation. I sometimes leave keg hops in until the keg kicks. Not ideal, but still not a big deal.

No need to sanitize the bag if its fairly clean.

I would do two things:

1. Adjust carbonation gently. Slowly off-gas to add the hops, keep at serving pressure after adding the hops. Lower-gravity beers tend to get that carbonic bite if you rush in force-carbonating, especially more than once.

2. Suspend (per jeffy) and shake to get the most out of 'em. If the beer is cold, extraction will be slower. I use a bag, some fishing line, and a (new) plastic bobber to suspend keg hops.

[DrewG]

1. Adjust carbonation gently. Slowly off-gas to add the hops, keep at serving pressure after adding the hops. Lower-gravity beers tend to get that carbonic bite if you rush in force-carbonating, especially more than once.

I set it and forget it. Carbed at 40f/10psi for a week and it seems to be where it should.

2. Suspend (per jeffy) and shake to get the most out of 'em. If the beer is cold, extraction will be slower. I use a bag, some fishing line, and a (new) plastic bobber to suspend keg hops.

Shake?
 

[jeffy]

1. Adjust carbonation gently. Slowly off-gas to add the hops, keep at serving pressure after adding the hops. Lower-gravity beers tend to get that carbonic bite if you rush in force-carbonating, especially more than once.

I set it and forget it. Carbed at 40f/10psi for a week and it seems to be where it should.

2. Suspend (per jeffy) and shake to get the most out of 'em. If the beer is cold, extraction will be slower. I use a bag, some fishing line, and a (new) plastic bobber to suspend keg hops.

Shake?

I don't think you need to shake the keg.  Just leave the hops in for the duration.
I sanitize the bag by putting it in boiling water.

[theDarkSide]

I dunk the bag in Star San and suspend with dental floss like others above.  My Arrogant Bastard clone didn't come out quite like I hoped so I am dry hopping in the keg with some Chinook.

[boapiu]

Just saw a project for a kegerator hop filter in an old BYO ( I am searching for recipe info). November 2010. It looks like one of those inline water filters full of whole leaf hops. pretty cool idea but probably too late unless you want to hold off enjoying your beer until you get it built.

[kraftwerk]

2. Suspend (per jeffy) and shake to get the most out of 'em. If the beer is cold, extraction will be slower. I use a bag, some fishing line, and a (new) plastic bobber to suspend keg hops.

I've never had a problem with hops bags sinking to the bottom of the keg or fermenter. In the bag, both pellet and whole leaf hops float on the surface, which can be a problem if it decides to get stuck in your purge valve when you are purging air at kegging.