pacanis, the two are not connected.
Only a stock made with bones will gelatinize when chilled.
Either stock or broth can chill with a layer of fat on top depending on the amount of fat put into the pot to start with.
I don't believe it! Wait, I have to sit down. This is a time when I dont' completely agree with everything that Andy said.
I did some research about the terms stock and broth the last time this topic came up. The word stock refers to the basic liquid derived from simmering bones, skins, and or meat in water. It is the basic liquid from which broths are made. Broths are stocks that have flavorings, and other componants added to the stock. The stock is just what the name implies, an ingredient stored for later use, as in stocking the shelves.
The gelatine found when stock is cooled is the result of collagens dissolved into the liquid. These collagens are cousins to protien and are found in the cartillage, bone marrow, and connecting tissues between muscles. I have taken grond beef and cooked it in a covered pan, to save the liquid, poured it off and refrigerated it, and the result was a meat-flavored gelatine with a layer of fat on top. I removed the hardened fat and was left with a wonderfully flavored stock from which to make gravies, soups, or whatever I wanted. Bones are not required to create gel from the cooled stock.
But that being said, the bone marrow contains other valuable nutrients and flavors that will enhance the quality of the stock. With poultry, the bones should be broken to let the liquid leach the marrow flavors and nutrients from them. The addition of slightly acidic veggies, such as celery or tomato will also aid in this process.
Espanole (sp), one of the mother sauces, is actually a broth, usually made from veal or beef stock, that has been combined with a browned roux, and clelery, onion, and carrot. It is reduced and strained to remove the veggie solids. This mother sauce can them be served as is, or made into one of many derivative sauces.
Soups are merely broths that have some kind of veggies, and or pasta/grains, and or meats added to them. There are also stocks made from nothing but veggies. But they won't gell.
The Jello you purchace in the store is the same colligen that gells your stock.
Also, the stock gelatine, when served cold, and sometimes flavored with herbs and spices, is called an aspic.
You can also make aspic by dissolving unflavored gelatine in hot water, and adding shrimp, or crab, or clambs, or poultry, etc. The gelatine around canned hams is the same substance as well.
Hope that helps clear things up a bit. And sorry Andy. You are still one of the most knowledgeable food guys I've had the pleasue of knowing.
Seeeeeeya; Goodweed of the North