Seriously Reduced Beef Stock – Worth three days preparation?

“Three days seems like a lot of trouble for a few cubes.” said the Wife. I was finding it difficult to disagree with her. Enthusiasm had once again got the better of me and I set about preparing some seriously reduced beef stock to use as a base for stews, sauces and gravies. My butcher friend, Long John, (not to be confused with his colleague Big John) had very generously dropped off some beef bones. “This shouldn’t take too long.” I mused to myself as I took out my new stock pot. How wrong could I be?