In the summer I brewed a honey ale with goldings hops, I dry hopped with about 40g goldings but due to the warm temps and a lack of control on my part, I didn't get to condition it properly and it tasted grassy right to the end. This one taught me a lesson - bottles are better in the summer when you don't have temp control! haha.
In april I brewed a Citra IPA, this started out the same, but after 3-4 weeks in the keg the grass flavours seemed to wear off.
I've just brewed up an APA using mostly Centennial and some Pacific Gem hops (ordered by accident thinking they were Pacific Jade, but meh, use 'em anyway.) This was dry hopped with about 80g hops total. I transferred to my plastic budget keg, purged the oxygen using the s30 gas valve and it's been dry hopped for about 5 days so far. How much flavour has been taken on I can't tell you, as I can't taste or smell a thing due to a chest infection. I've used this method because I've lost two brews to a secondary vessel before, so I simply don't trust it, whereas a keg under pressure is much less likely to oxidize.
Rambling aside, quick questions on this -
1) I read anywhere from 3 days to 2 weeks is usual for dry hopping. I'd like to avoid grassy flavours, would a week be sufficient for plenty of IPA flavour? Hopefully I can smell and taste in a few days because if there's not enough flavour, I can dry hop again with some Topaz I have ready for another brew.
2) Could the problem be that I'm dry hopping in the keg rather than a secondary and the grassy flavours are forever entombed in the keg? How could I get around this if so? I have a keg that's about to run out, so would transferring over to that reduce the grassy flavours, or should I er, Degass it, reseal and then blast the remaining air out with co2?
3) Will this just settle itself out now? I have access to cold conditioning as we're regularly hitting 6c (42 farenheit) in the conservatory and in my experience that's been enough to condition my winter beers to an acceptable standard.
Here's the rough recipe, I changed it slightly on brewday - more centennial for aroma and less pacific gem overall. It tastes great so far, and due to a slight cock up it had to be fermented with a Belgian yeast.