When you're making soups, sauces, and stews, as well as other preparations that involve liquids (like cooking rice or legumes), it's always a good idea to start with something more flavorful than plain water. Your usual options are either broth or stock.
But what is the difference between chicken stock and chicken broth, and when should you use one or the other? Let's start by looking at the difference between stock and broth generally, and then look at the particulars as it relates to chicken.
What Is Stock?
Stock is a flavorful liquid made by simmering bones, along with aromatic vegetables like carrots, celery, and onions, plus seasonings and spices like black pepper and fresh herbs.
Gelatin is a key characteristic of a good stock and you'll know it by the fact that it will jell when you cool it. A gelatin-rich stock will add richness and body to sauces and soups that are made from it.
The key here is that stock is generally an ingredient in some other dish, as opposed to something that is served on its own. This is why the seasonings named above do not include salt. Salt is not typically added to a stock, but rather, it's added to whatever the final dish is.
What Is Broth?
Broth, on the other hand, is a flavorful liquid prepared by simmering meat and vegetables, but no bones. (The term "bone broth" might lead to some confusion here, but bone broth is just a fancy name for stock.)
Indeed, the term vegetable stock is really a misnomer, since vegetables don't have bones. Anything called vegetable stock is really just vegetable broth.
Again, the distinction is more than just about a name. The key difference is that a stock will be rich with gelatin, whereas a broth will not. And because there's no collagen to extract, simmering broth takes far less time than stock—usually no more than 30 minutes.
How Chicken Stock Is Made
Chicken stock is prepared by simmering chicken bones, along with aromatics and seasonings. Typically the bones are first blanched, then transferred to a fresh pot of cold water which is gradually heated to a simmer.
While there will almost always be at least some meat still on the bones, the main ingredient is the bones. You can make chicken stock by simmering a whole chicken carcass leftover from roasting a chicken. While you'll obtain more gelatin from a carcass that hasn't been cooked once already, chickens are so rich in collagen that even simmering a cooked carcass will yield plenty of gelatin.
Note that commercial products labeled "chicken stock" don't usually jell, which means that even if some bones are used in their preparation, they are essentially chicken broth.
How Chicken Broth Is Made
Chicken broth is a flavorful liquid made by simmering chicken meat along with aromatics and seasonings. One consideration with making chicken broth is the fact that the cook must balance the desire to extract flavor from the chicken with the fact that extended simmering causes the chicken itself to become tough and grainy.
This effect might not be important if the meat is going to be strained out, although this is an extravagant use of chicken meat. If the meat is to be left in the broth, simmering it gently and for a short time is best.
When to Use Each One
Whether to use chicken broth or chicken stock depends on what recipe you're preparing. If you're making a simple soup like chicken noodle soup and the liquid is going to be consumed as is, then you can use chicken broth.
If you're performing additional steps to your liquid, like thickening it because you're using it as the starting point for making a velouté sauce, then you'll want the extra body that comes from the gelatin, and thus chicken stock is the way to go.