I wanted to braise some beef and got beef shanks. They've been simmering for over an hour on a burble (barely a bubble) but they feel tough like leather. Now I know 1 hour is not enough, but some recipes say 2 hours, others 5 hours, I've even seen 9 hours, I don't have that kind of time until dinner time... but I do have another three hours to play with. Well anyway I guess my question is do I stand a chance? Will this end up falling off the bone and melting in my mouth like a chuck roast or short ribs would, or am I doomed to get some leathery beef? Thanks guys.