I received this e-mail today, and I thought it was a great question!

“Hey Cat. I’ve been experimenting with making things I would usually buy prepared
– such as pasta sauce, hummus, pesto, etc. – myself at home. Many soup recipes
call for some sort of broth, which I   have been buying in cartons at the store.
But I came across a recipe for homemade stock to cook in big batches to freeze
and use in various soups. I’m wondering if stock can be substituted for broth,
and what the difference is. I imagine it’s more or less the same, but then why
do they have different names?”

Thanks for your help! ~Nicole

I wasn’t even 100% sure, and so I Googled it and found this answer:

In stock, such as chicken, beef, or fish stock, animal bones are the main ingredient. These bones are typically braised first, then transferred into a large kettle or pot with water to cover. Mirepoux, the classical French culinary term for a mixture of carrots, celery and onion, is added, along with several bouquet garni — a cheesecloth sachet containing bay leaf, peppercorns, thyme, and parsley. Stock is heated slowly over a low flame for several hours, preventing the water from boiling. Cooking the stock this slowly allows marrow to dissolve and the bones to release their gelatin. Tiny bubbles of fat rise to form a layer at the top. Once the fat is skimmed off and the ingredients discarded, the stock is ready to use.

It is the gelatin and marrow found in bones that give stock a rich flavor and leave a heavier, almost velvet-like feeling in the mouth. Marrow and gelatin also allow stock to refrigerate well, as the stock will congeal into a solid mass. Typically, chefs chill stock in long sheet pans, then cut into cubes for easy storage. Stock is used as a base for a variety of soups and sauces and can be further reduced to form a glaze.

Broth, on the other hand, is mostly made from meat. While the cooking process is very similar to stock, the results are slightly different. Broth is more subdued than stock, as it tiptoes lightly into the mouth with a softer texture and milder flavor. Broth’s taste is known to stand on its own, as the meat gives broth a finished distinction. Being finished however, might be the reason that broth does not perform as well as stock in completing sauces and glazes. The lack of gelatin requires the addition of fat, such as cream or butter, to enhance a sauce.