“I’m going to use Swiss cheese to thicken this beef stew,” my housemate said. Undeterred by my observation that it wouldn’t work and unmoved by my pleas not to waste the cheese, he went ahead. As we surveyed what turned out to be a decent beef stew studded with little balls of melted cheese scattered unpleasantly throughout, he said unhappily, “It didn’t do what I thought it would.” Uncharacteristically, I let the lesson sink in on its own.
Another housemate once asked the question, “Who says you can’t put cumin and tarragon in tomato sauce?” Ignoring my answer, “Just about everyone who knows how to cook,” she went ahead. I ate dinner out that night and I think she wished she could, too. After a friend said his turkey would be cooked for 36 hours at 150, I found myself too busy to eat at his house that Thanksgiving weekend. 150 degrees is the preferred temperature of many food toxins and I saw no need to risk gastric distress or worse. I did warn him, but he had read about this extra-slow cooking somewhere and was undeterred. Fortunately, the turkey was not stuffed and no one died, but I never regretted my decision.
I’ve always said that not everyone has to be a good cook; all that is needed is to be a good eater. However, if you are going to cook, a little knowledge about why things behave as they do will serve you well. We are not talking about some hidebound, cleaver-wielding French chef who says “Zees is za way we do eet” or your grandmother insisting that you “cook it until it looks right.” Anyone who cooks has noticed how ingredients behave in various situations. Add a soupcon of knowledge and your cooking will improve dramatically.
Take the case of the unthickened beef stew. David Joachim and Andrew Schloss, authors of “The Science of Good Food” (which was featured in the Oct. 10 Chef’s Best), talked about that very situation during a recent visit to Different Drummer’s Kitchen in Northampton. Meats are surrounded by connective tissue made primarily of the protein called collagen. As it cooks, the collagen dissolves, then forms a gel in the liquid, trapping water in a thick mass. It is why cold stocks get that jellied look and why meat drippings in a pan form a jelly. Gelatin is simply the purified form of collagen. Cheese as a thickener, by the way, never comes up when you talk to cooks.
“Colloidal gel of chicken bone extract” does not appear on many menus, and as a home cook, you’re unlikely to view your simmering pot of meat and vegetables as a chemical stew. But as an observant cook, you’ve noticed that the liquid thickens differently than when you add a flour and water roux. The mouth feel, the way the liquid tastes and feels in your mouth is different, fuller and richer somehow. That’s the collagen. When a soup tastes watery, Andy Schloss observed, it simply means that it slides off your tongue before you can fully absorb the flavor.
Try this experiment. Take a quart of chicken broth and thicken half of it with roux (1 tablespoon butter and 1 tablespoon flour, cooked until light brown). Thicken the other half with about a half teaspoon of gelatin, softened first in some liquid. Which feels better in the mouth? Which tastes richer? Brown roux adds flavor, certainly, but you’re looking here for the thickening only.
Connective tissue is more plentiful in parts of the animal that are connected to bones and that do the work. Lamb shanks are the bottom parts of lamb’s legs, which are in constant use. The muscle gets tougher, but more flavorful. Filet mignon comes from the beef tenderloin, a muscle along the backbone that gets almost no workout. That’s why filet mignon is so tender and so bland. Lamb shanks are served in a sauce made from their cooking liquid, which is rich with flavor and wonderfully thick with collagen. Filet mignon, on the other hand, is broiled or grilled and served with a sauce like Bearnaise, which is added at the end and not composed of any of the cooking liquid. The mouth feel in a Bearnaise sauce comes from an emulsion of egg proteins and the reduced vinegar in the sauce.
You can compensate for the toughness of meat by long moist cooking. Way back when my friend Richy and I were hitchhiking across the U.S., cooking dinner in exchange for a place to drop our sleeping bags, we bought some slices of beef shank to grill. No matter what we did, that meat remained as chewy as a rubber ball. We’d have done better to toss it in a pot with some vegetables and simmer it overnight. Beef shank makes a flavorful stock but a terrible steak. You live, you learn.
The subject of long low cooking versus high hot cooking for turkeys also came up during Joachim and Schloss’ class at Different Drummer’s Kitchen. Schloss observed that the long low school of thought correctly kept the cooking temperature low enough to prevent the water from boiling out of the meat. “Put it in a 400-degree oven for an hour to kill any bacteria and then lower the heat to the temperature you want it to achieve,” he said. “You can cook it at 170 for a long time without drying it out.” Ah, that crucial 400-degree bacteria-killing first step was lost on my friend, but is so important. When you stop to think that most “stomach flu” is really mild food poisoning, why play with your guests’ health?
During the class, I heard someone observe that he ought to get science credit. I don’t think you need to go that far, but if you enjoy Alton Brown’s show on the Food Network, you’ll notice that he often looks at food from its physical and chemical properties using goofy and intentionally cheesy props. Harold McGee’s classic “On Food and Cooking” should be on every serious cook’s shelf. It comes out about once a week in my house to settle an argument or answer a question. “The Science of Good Food” is organized like an encyclopedia and what it lacks in electron microphotographs of flour it makes up for in recipes, tips and general readability.
Recipes are key. After all, food may be fuel and cooking may be the conversion of raw ingredients into more easily digested components, but man and woman do not live by chemistry alone. No matter how good the chemistry, if it doesn’t taste good, it’s not worth cooking.
Originally published in Daily Hampshire Gazette, Friday, October 31, 2008