So I just roasted a whole chicken and finished carving/cleaning the carcass today. I discovered a great deal of congealed red matter surrounding many of the joints and bones. Looks like congealed blood. Normally, I wouldn't worry about it, except that there's a lot more of it than there usually is. And it's a brighter red, as opposed to the dark reddish brown I'm used to. Should I be worried? Did I undercook the chicken? Was this chicken just not as well drained as ones I've gotten previously?
This exact thing happened to me about a month ago - roast whole chicken, bright red leaky blood around the bones and joints.
I looked it up back then. I didn't find a truly authoritative source like the USDA, but I did find several instances of people saying that this happened even with highly overcooked chicken. I also found several links similar to this one:
The author (a Ph.D according to that page) did a number of experiments where he cooked a chicken and checked the internal temperature everywhere, ensuring that it was in fact pasteurized and thus free of any bacteria, and parts of it were still bloody on the inside.
According to him (and a few other sources I found), it's because the chickens are very young and their bones have not hardened properly; when you cook them, the marrow seeps out and ends up looking as you describe.
If you're using a meat thermometer to test the chicken for doneness, and you are certain that it got hot enough, then don't worry about the blood. It's not appetizing, but it's not harmful either.
FWIW, I ate the chicken when it happened to me, and did not get the slightest bit sick.
In an of itself, brighter blood doesn't mean anything, so I wouldn't worry about it, unless you also noticed any of the following: