In the test kitchen, we start every day by asking questions. Then, we construct kitchen experiments to answer those questions. Read on to find out what happened when we took some of the most popularly held assumptions about cooking—many of which we took at face value ourselves—and put them under the microscope.
Myth: The Best Part of a Tomato is The Flesh.
Fact: The seeds and jelly contain the most flavor.
Many believe it imperative to remove the seeds and jelly of tomatoes because they detract from the texture of your dish. That may be, but they affect flavor, too. We made two tomato gratins, one with intact tomatoes and the other with the seeds and jelly removed. We found that the gratin with the intact tomatoes had a richer, deeper flavor. This is because the seeds and jelly actually contain three times the amount of flavor-enhancing glutamic acid as the flesh. (Also called glutamate, this is the compound that supplies the savory quality known as umami in many foods.) Sometimes removing seeds may be necessary, but it should be a last resort.
Myth: A Slammed Door will Ruin a Soufflé or Cake.
Fact: Slamming won't make a difference.
Soufflés and cakes rise as tiny air bubbles in the batter expand in the heat of the oven. To find out if slamming the door shut would interrupt the process enough to spell disaster, we mixed batters for muffins, yellow cake, angel food cake, and cheese soufflé and loaded them into hot ovens. Just before each item reached its maximum height, we opened the oven door and gave it a hard slam. The muffins emerged unharmed, as did the yellow cake. Even the notoriously fragile angel food cake and the soufflé survived. A properly developed foam is pretty resilient.
Myth: Bread Stales Because It Loses Moisture.
Fact: Bread stales because starch molecules absorb moisture.
Once exposed to air, bread starch undergoes a process called retrogradation: The starch molecules begin to crystallize and absorb moisture, turning the bread hard and crumbly. This is why for certain recipes (like stuffing), you should dry bread in the oven (to drive out moisture) instead of letting it go stale.
Myth: Salt Makes Water Boil Faster.
Fact: Salt will increase the time it takes water to reach a boil—but only if you add a whole lot of it.
When we conducted an experiment (bringing 4 quarts of water to a boil with and without 1 tablespoon of salt, or the amount of salt we use to cook 1 pound of pasta), we found that salted and unsalted water came to a boil in the same amount of time: 171/2 minutes. A whopping 1½ tablespoons of salt per quart of water is required to raise the boiling point by just 1 degree, thus slightly increasing the time it takes the water to reach a boil. Those proportions yield a super-salty solution, one that we wouldn't use to cook with anyway.
Myth: Cooking Wine Removes All Its Alcohol.
Fact: Cooking reduces the alcohol content but rarely eliminates it.
When alcohol and water mix, they form an azeotrope—a mixture of two different liquids that have a single, constant boiling point. This means that even though alcohol evaporates at a lower temperature than water, the vapors coming from an alcohol-water azeotrope will contain both alcohol and water until the entire mixture is gone. In sum, about 5 percent of the initial alcohol content will remain no matter how long you simmer the mixture.
Cooking with Wine
Wine and Water
When simmering a mixture of water and wine, alcohol molecules are a major component of the vapor in the beginning.
Water and Wine
After simmering for a while, water molecules compose the majority of the vapor. It is impossible to get rid of all the alcohol unless all of the liquid evaporates.
Myth: Cooking in Liquid Keeps Meat Moister.
Fact: Despite the wet conditions, braising adds no moisture.
We simulated braising by placing samples of beef chuck, along with measured amounts of broth, in individual vacuum-sealed bags. We submerged the bags in water held at 190 degrees (the temperature of a typical braise) for 90 minutes. The weight of the meat decreased an average of 12.5 percent during cooking while the volume of liquid increased, demonstrating that moisture had been pulled from the meat into the surrounding liquid, not the other way around. Braised meat seems moist not because of the moisture surrounding the meat but because of the temperature at which the meat cooks. Gentle cooking is one way to help break down the meat's connective tissue and collagen, which lubricate and tenderize its fibers.
Measuring Moisture in Meat Before and After Braising
We weighed our samples of beef chuck before and after braising in vacuum-sealed bags and found that the meat lost 25 grams of liquid on average, proving that braising does not retain moisture.
Myth: Oil and Vinegar Don't Mix.
Fact: They can—and do—when properly emulsified.
An emulsion is a combination of two liquids that don't ordinarily mix, whisked strenuously until one breaks down into droplets so tiny that they remain separated by the other liquid. The addition of an emulsifying agent (like mayonnaise or mustard) helps the two liquids stay together in a unified sauce. We made vinaigrettes with each emulsifier and found that the mayo sample lasted 1½ hours while the mustard dressing broke after 30 minutes. A sample with no emulsifier began to break immediately.
Myth: Potatoes Can Make a Dish Less Spicy.
Fact: You need fat or sugar to reduce the heat.
We tried adding potatoes to foods to tame spiciness, but it simply doesn't work. There is another solution: Add ingredients from the opposite end of the flavor spectrum to balance things out. Depending on the recipe, you can add a fat (such as butter, cream, sour cream, cheese, or oil) or a sweetener (such as sugar, honey, or maple syrup) to counteract the offending ingredient. Obviously, it wouldn't make sense to add cheese to a too-spicy Thai beef stir-fry, so use your best judgment.
Myth: All Parts of a Chile are Equally Hot.
Fact: The pith contains the real spicy stuff.
All chiles get their heat from a group of chemical compounds called capsaicinoids, the best known being capsaicin. It's often thought that the seeds have more heat than the flesh, but they are essentially guilty—or hot—by association. Most of the capsaicin is concentrated in the inner whitish pith, with progressively smaller amounts in the seeds and the flesh. We separated the outer green-colored flesh, the inner whitish pith, and the seeds from 40 jalapeños and then sent them to a food lab for analysis. We found that there were just 5 milligrams of capsaicin per kilogram of green jalapeño flesh, 73 milligrams per kilogram in the seeds, and 512 milligrams per kilogram in the pith.
Myth: Acidic Marinades Tenderize Meat.
Fact: In actuality, they can make meat mushy.
To tenderize meat, you have to break down muscle fiber and collagen, the connective tissue that makes meat tough. While acidic ingredients do weaken collagen, their impact is confined to the meat's surface—and if left too long, acids turn the outermost layer of meat mushy, not tender. To minimize mushiness, we use acidic components sparingly and only for short marinating times. Truly tender meat comes down to the cut, cooking time, method, and temperature. Highly salted marinades can also act as brines, helping meat retain moisture and cook up more tender.
Myth: Pasta Must Be Cooked in Lots of Water.
Fact: You don't actually need a full pot.
If you don't have a pot large enough to handle the amount of water a pasta recipe calls for, don't panic. We've successfully cooked a pound of spaghetti in 2 quarts of water—about half of what a recipe usually suggests. As long as you stir the pasta frequently (we use tongs), it will be indistinguishable from pasta cooked in a larger quantity of water. (Just keep in mind that the pasta cooking water will be starchier than usual—which can be a good thing if you want your sauce to cling better to the pasta.)
Myth: Searing Meat Seals in Juices.
Fact: Searing just creates a crusty layer of flavor.
We cooked two batches of rib-eye steaks, searing the first batch in a skillet over high heat and then cooking the steaks in a 250-degree oven until they reached 125 degrees. For the second batch we reversed the order, first baking the steaks until they reached 110 degrees and then searing them until a crust developed and their interiors hit 125 degrees. We weighed the steaks before and after cooking and found that both sets had lost around 22 percent of their weight. If searing truly seals in juices, the steaks seared first (while raw) would have had more moisture trapped inside them (and thus less weight loss) than the steaks seared after cooking in the oven.