a bit of kitchen alchemy

I was reading this article in the NY Times (written by Mr. Food Science himself, Harold McGee) and was fascinated by the atypical use of gelatin to filter any particulate matter out of a stock or puree, resulting in a liquid which possesses the flavor essences of whatever you happened to be making -- essentially a way to make a consommé of whatever you might want.

That got me to thinking (sometimes dangerous, in this case helpful). One of the things that separate restaurant chefs from home cooks is the chef's access to various stocks -- an ingredient that most home cooks don't have the time or inclination to prepare. As such, we are left with broths in various forms (home made, concentrates, pastes, boullion, and ready-to-use). These are fine products, especially if you have access to quality brands. But they lack one very special thing: gelatin.

Stocks are usually made of the bones of an animal. Either freshly butchered or roasted, they are then slowly and gently simmered, allowing the various proteins in connective tissues (collagen chief among them) to turn into gelatin. Sometimes aromatic vegetables are included, but salt almost never is, as stocks are usually reduced later and would then become too salty. Stocks are then typically clarified by some means and then refrigerated, ready to use at a moment's notice.

Home made broths are usually made from the meat of an animal. While the meat is full of flavor and protein, it's not the kind of protein that will turn into gelatin. This is a problem, as it is the gelatin in a stock that gives it, to quote Alton Brown, "lip-smacking goodness." Essentially, gelatin provides a fatty, unctuous mouthfeel (in a good way) that gives soups and sauces more substance.

My immediate thought was, "Why not add gelatin to a broth?" I tried it and, frankly, it works. One packet of gelatin for every 6 cups of liquid gave it the same texture as long-simmered stock and filled in remarkably well where stocks were called for. So feel free to experiment with this substitution.

If you're in need of a recipe, try this one for mushroom barley soup if you are in an area that is starting to get chilly:

3 tablespoons vegetable oil
1 medium onion , cut into medium dice
2 medium carrots , cut into medium dice
2 medium celery stalks, cut into medium dice
12 ounces domestic mushrooms or wild mushrooms, cleaned and sliced thin
1/2 teaspoon dried thyme or 1 1/2 teaspoons minced fresh thyme
1 bay leaf
1/2 cup canned tomatoes , cut into medium dice
6 cups chicken stock (home made or a quality store brand)
1 packet unflavored gelatin
1 cup pearl barley
1/4 cup minced fresh parsley leaves
Table salt and ground black pepper

Heat oil over medium-high heat in a soup kettle or Dutch oven. Add onion, celery, and carrots; sauté until almost soft, 3 to 4 minutes. Add mushrooms; sauté until softened and liquid almost evaporates, 4 to 5 minutes longer. Add thyme, bay, and tomatoes, then broth, gelatin, and barley; bring to simmer. Reduce heat to low; simmer until barley is just tender, 45 to 50 minutes. Stir in parsley, adjust seasonings, including salt and pepper to taste, and serve.