sorry, I just went into my GR, and it's actually tags.
on the far right hand from where you star a post, you have the option to edit the tag. So you can create a new one or use an existing tag. let's say there's a chicken dish you like...you can tag it "chicken" or anything else you want. There will be a list of tags on the left hand side underneath all the blogs you read.
I also put all the blogs I read in specific folders. On the bottom, there is a manage subscriptions link. You can create folders there.