So the black plastic part inside of my keg lock in my corny keg fell off and is now sitting in the beer. I'm hoping that it will not do anything to the beer, and that I will have no off flavors from it. I'm assuming I will be okay if I get a new keg tomorrow and just transfer it to there?
Are you talking about the large o-ring that makes the seal with your lid? If so, it shouldn't do any harm . . . when it happened to me I just replaced it and drank the keg as normal. Never saw the mischievous part until I washed the keg. However, if your keg spent any time without this o-ring I would do some serious "burping" when it's replaced.