I've been making chicken stock for a while now, but I never was really satisfied. The stuff I ended up with tasted pleasant enough, but it unfortunately didn't seem to really be stock. Classic stock (though there is some debate about definitions) should "gel" at room temperature. The slow simmer draws out all the connective tissue and makes the final product sort of like a meat jell-o. It doesn't sound appetizing, but it's actually quite desirable.
I haven't been able to achieve that so far, not until this latest batch. I tried a couple different things, either might have done it. First, I included three chicken carcasses rather than my usual two. The theory there was that it would allow more of the good stuff to get leeched out. Second, I included the drippings from the original roasting. These drippings, I think, included a lot of the gelatin that comes off in the initial cooking. That probably helped, too.
The end result is a fine, flavorful stock that I can use for all kinds of things. I've got a bunch of "stock cubes" in the freezer right now, from putting the stock in ice trays. I'll throw it in a lot of things I make to give it an extra kick. On top of that, I often just boil a few cups of stock, throw in some vegetables and a bit of leftover chicken meat for an excellent, nutritious, and relatively low-fat chicken soup. (The fat gets skimmed off the top of the stock during the cooking process.)
Next up, I'm going to experiment a bit with some of the added ingredients. For example, some people think the classic celery gives the stock a too-bitter flavor, as traditional as it is. (But then, traditionalists would probably cringe at the fact that I put hot peppers in my stock). I also want to put in some vinegar to help extract more of the calcium and other minerals from the bones, making the stock that much more nutritious.
I'll probably make some beef stock soon, too. My local butcher doesn't carry any poultry (!), but I shouldn't have any trouble getting beef bones.