A Btu is an amount of energy, just as a calorie is an amount of energy. Both are most commonly used to measure amounts of heat. The Btu, which stands for British thermal unit, was invented by engineers, so while it makes sense to the guys who design the stoves, it doesn’t mean much to […]
Food
Why Does It Take Such a Long Time To Reduce a Stock?
Evaporating water sounds like the simplest thing in the world. Why, just leave a puddle of water standing around and it evaporates all by itself. But that takes time, because the necessary calories won’t flow into the water very fast from the room’s relatively cool air. Even on the stove, where you’re feeding lots of […]
Will a Pot of Water Boil Faster If You Put the Lid On?
As a pot of water is heated and its temperature goes up, more and more water vapor is produced above the surface. That’s because more and more of the surface molecules gain enough energy to leap off into the air. The increasing amount of water vapor carries off an increasing amount of energy that could […]
Does Warm Water Take Longer To Boil Than Cold Water Because It Is Cooling Down?
Something about momentum? I’ll bet, because if an object is already falling, in temperature, presumably, it should require extra time and effort to turn it around and make it rise. You first have to kill its downward momentum. That’s all very well and true for physical objects, but temperature isn’t a physical object. When the […]
How Long Does It Take To Boil Water At High Altitudes?
The elevation at La Paz runs from 10,650 to 13,250 feet above sea level, depending on which part of town you’re in. And as you are aware, water boils at lower temperatures at higher elevations. That’s because in order to escape from the liquid and boil off into the air, water molecules have to fight […]
How Does Cutting 3,000 Calories Equal To Losing a Pound of Fat?
Not being a nutritionist, I asked Marion Nestle, professor and chair of the Department of Nutrition and Food Studies at New York University. “Fudge factors,” she said. First of all, the actual energy content of a gram of fat is closer to 9.5 calories. But that would only make the discrepancy bigger. The fact is […]
How Much Energy Is a Calorie and Why Do Calories Make Me Fat?
A calorie is a much broader concept than just heat; it’s an amount of any kind of energy. We could measure the energy of a speeding Mack truck in calories, if we wanted to. Energy is whatever makes things happen; call it “oomph” if you wish. It comes in many forms: physical motion (think Mack […]
How To Boil a Live Lobster
At the fish market, select one lively, tail-flipping, claw-raising lobster per person. You pick up a lobster by grasping its back, behind the head. If it droops when picked up, forget it and come back another day; it’s not fresh. Take the lobsters home in a container that allows lots of breathing space and keeps […]
What Is the Best Way To Cook a Live Lobster? Boil It or Steam It?
To find an authoritative answer, I went to Maine and interviewed several leading chefs and lobstermen. I found two distinct camps: the staunch steamers and the passionate plungers. “I plunge,” defiantly declared the chef at a well-known French restaurant. He plunges his lobsters into boiling water laced with white wine and lots of peeled garlic. […]
Why Are Mussels the Best Type of Seafood Ever?
Mussels are nature’s fast-food gifts from the sea. They are beautiful to behold in their ebony shells, decorated with concentric growth lines. They cook almost instantly (they’re done when their shells pop open) and are very low in fat and high in protein. Their texture is meaty, and they taste of the sea, a little […]
What Is the Difference Between Clam and Oyster Shells and Shrimp and Crab Shells?
We call them all shells because they are worn on the outside, but when we talk about “shellfish,” we’re including two totally different classes of animals: crustaceans and mollusks. Among the crustaceans are crabs, lobsters, shrimps, and prawns. Their shells are horny, flexible plates of hinged “armor.” The top covering of a crab or lobster […]
Do Live Clams Need To Be Cleaned Before Cooking and Eating Them?
They should be, but they really don’t have to be. That step is often skipped. As they arrive from the ocean or the fish market, live clams generally need to be purged. When they were snatched from their snug little beds in the sand, they pulled in their siphons and clamped their shells together tightly, […]
What Is the Easiest Best Way To Open Live Clams?
Almost as much human resourcefulness has been expended on shucking clams as on opening childproof medicine bottles, but with far more injuries. People have seriously recommended everything from hammers, files, and hacksaws to execution in the microwave chamber. But brute force is entirely unnecessary, and microwave heat can seriously compromise their flavor. To open clams […]
Are Clams and Oysters On the Half Shell Still Alive When We Eat Them?
You’re on vacation at the shore, right? Seafood restaurants abound. Many have raw bars, at which hordes of heedless hedonists are slurping hundreds of luckless mollusks that have been forcibly demoted from bivalve to univalve status. It’s only natural to be squeamish about chomping on a creature so recently relieved of its shielding shells and, […]
Why Is Caviar Served With a Special, Fancy Spoon Made of Gold?
One can imagine several reasons. Merchants assume that anyone who eats caviar regularly is an easy sell. Caviar deserves it. And least romantically, there is a chemical reason for it. Caviar is the roe of the sturgeon, a huge, dinosaur-era fish with armored plates instead of scales. The sturgeon lives primarily in the Caspian and […]
Where Does Imitation Crab Meat Come From and What Is Surimi Made Of?
Surimi is fish flesh that has been minced and fabricated into crab-and shrimp-like shapes. Developed in Japan to utilize the waste scraps from filleting and to exploit some of the less desirable fish species caught in the nets, it has gained a foothold in the United States as a low-cost alternative to the real things. […]
Why Does Fish Go Bad So Much Faster Than Other Meat Like Beef?
People put up with fishy-smelling fish because they’re probably thinking, Well, what else should it smell like? Odd as it may seem, though, fish needn’t smell like fish at all. When they’re perfectly fresh, only a few hours removed from carousing around in the water, fish and shellfish have virtually no odor. A fresh “scent […]
Why Does Fish Cook So Much Faster Than Other Meats?
Meats, like wines, can be either red or white. Beef is red; fish and shellfish are generally white. Salmon are pink, rosé, if you like, because they eat pink-shelled crustaceans. Flamingos, if you care, are pink for a similar reason. In the kitchen, we soon learn that white fish flesh cooks much more quickly than […]
How To Make the Perfect Chicken or Turkey Gravy Every Time
There are three important things to remember when making gravy: Combine and cook equal parts fat and all-purpose flour. Whisk in the right amount of broth to the consistency you like. Simmer gravy for a total of 7 minutes. The standard proportion for gravy is 1 part fat, 1 part flour, 8 or 12 parts […]
Why Does My Turkey Gravy Turn Out To Be Either Lumpy Or Greasy?
It doesn’t have to be either lumpy or greasy. We all know people who can make it both lumpy and greasy at the same time, don’t we? Lumps and grease arise from the same basic phenomenon: Oil and water won’t mix. In your gravy, you want some of each, but you have to trick them […]
How Do I Use the Drippings From a Roast Chicken?
No. If you have to ask, you don’t deserve them. Pour off the fat, scrape the rest of the “ook” into a jar, and ship it to me by overnight express. Seriously, this stuff is composed of marvelously flavorful juices and gels, and it would be a crime to feed it to your dishwashing machine. […]
Where Does the Foamy, White Scum When Making Chicken Soup Come From?
The stuff is coagulated protein, held together by fat. While it won’t hurt you, it won’t taste good and it’s best to remove it on purely aesthetic grounds. When protein is heated, it coagulates. That is, its long, convoluted molecules unfold and then clump together in new ways. What happened was that some of your […]
What Does Marinate Overnight Mean In a Recipe?
I’m with you. Why overnight? Are we to believe that daylight somehow interferes with the marinating process? What if it’s only two o’clock in the afternoon when we arrive at the critical point in the recipe? How early can “overnight” begin? If we do leave it overnight, must we proceed with the recipe the moment […]
Why and How Does Brining Make Meat, Poultry, and Fish Juicer?
Brining, soaking meat, fish or poultry in a solution of salt in water, is far from new. Surely, at some time in maritime history, someone discovered, accidentally, perhaps?, that meat that had soaked in seawater was juicier and had better flavor when cooked. How does brining work? What does a bath in salt water accomplish, […]
How Is Meat Like Ham and Fish Preserved Without Refrigeration?
Meats don’t spoil because they’re “cured,” which is a catch-all term for any process that inhibits bacterial growth, even at room temperature. But hams can be bewildering. How are they cured? Are all hams salted? Smoked? Do you have to soak them? Cook them? There is no single set of answers to these questions because […]
What Is the Best Way To Skim the Fat From Soup and Stock?
Recipes tell you to “skim the fat” from soups and stews as if it were as easy as peeling a banana. Supposedly, you just grab a spoon and scoop off the layer of fat without removing any of the underlying solids or liquids. But the word skim is a scam. For one thing, it’s hard […]
Why Should You Never Touch the Bone When Using a Meat Thermometer?
I hate warnings without reasons, don’t you? All they do is dispense anxiety without information. Whenever I see an “open other end” warning on a box, I open the wrong end just to see what will happen. I’m still alive. Bone is a lesser conductor of heat than meat is. For one thing, bone is […]
Why Is the Meat Nearest the Bone Always the Best and Sweetest Tasting?
We can take that remark with a grain of sugar, because the word sweet is both overused and misused in gastronomic parlance. It is often used just to mean pleasant tasting and not meant to be taken literally. Perhaps that’s because, of the fundamental tastes that have been identified in humans, sweetness is the one […]
Why Do Bones Make Soup, Stew, and Stock Taste Better By Adding Flavor?
Dem bones are an essential ingredient in making a soup, stock, or stew, every bit as essential as the meat, vegetables, and seasonings. Their purpose may not be obvious, however, if we think of them as hard, nonreactive mineral matter. Yes, their structural material is mineral: calcium phosphates, to be specific. But calcium phosphates don’t […]
What Does Prime Beef Mean and Where Does Prime Rib Come From?
USDA Prime is indeed the finest and most expensive grade of beef. But we have all at one time or another been subjected to a $5.95 (salad bar included) slab of tough, dry “prime rib” rimmed with vulcanized-rubber fat that clearly deserved to be stamped “USDA Inedible.” Is there some misrepresentation going on here? Not […]
Why Is Ground Beef Dark On the Inside But Bright Red On the Outside?
A freshly cut meat surface isn’t bright red; it’s naturally purplish because it contains the purplish-red muscle protein, myoglobin. But when myoglobin is exposed to oxygen in the air, it quickly turns into bright, cherry-red oxymyoglobin. That’s why only the outer surface of your ground beef is that nice, bright red color that we generally […]
Why Is Red Meat Red and White Meat White and Where Does the Color Come From?
There is virtually no blood in red meat. Most of the blood that circulates through a cow’s veins and arteries never makes it to the butcher shop, much less to the dinner table. Not to get too graphic about it, but down at the slaughterhouse, just after the critter is dispatched, most of the blood […]
People Just Love To Eat Meat and Fish
We humans are an omnivorous lot, with teeth and digestive systems well adapted to eating both plant and animal foods. But animal rights activists notwithstanding, it’s an undeniable fact that in our society, meat and fish are most often the center of the plate, the star players in our main dishes. Of the virtually unlimited […]
Why Are Hominy Grits Made With Lye When It’s Corrosive?
Yes, but it has been thoroughly washed out before the grits ever get near your breakfast plate. The word lye is related to the Latin for wash, and originally referred to the strong alkaline solution obtained by soaking, or washing, wood ashes in water. (The alkaline material in wood ashes is potassium carbonate, and because […]
How Toxic Are the Eyes of a Potato?
Not as dangerous as some well-meaning friends who spread scary stories. But there is a small grain of truth to the story. When potatoes were introduced into Europe in the second half of the sixteenth century, they were suspected of being either poisonous or aphrodisiac or, an intriguing thought, both. (What a way to die!) […]
Why Do Some Potato Chips Have Green Edges and Are They Safe To Eat?
Those chips were sliced from green-surfaced potatoes, and they therefore contain small amounts of toxic solanine, which is not destroyed by frying. It’s okay to eat them, because in order to experience any ill effects you’d have to eat so many bags of chips that you’d turn greener around the gills than they are around […]
Why Are Potatoes With Green Skin Toxic and Unsafe To Eat?
It’s not green because it’s unripe; potatoes are ready to eat at any stage of growth. And they’re not flaunting the green because they’re a traditionally Irish food. The green color is Mother Nature’s Mr. Yuk sticker, warning us of poison. Potato plants contain solanine, a bitter-tasting member of the notorious alkaloid family, a group […]
Where Does Vinegar Come From and What Is Vinegar Made of?
Vinegar has been known for thousands of years. No one even had to make it in the first place, because it actually makes itself. Wherever there happens to be some sugar or alcohol lying around, vinegar is on the way. Any chemist will tell you without a moment’s hesitation that vinegar is a solution of […]
Why Does Lasagne and Spaghetti Eat Holes In Aluminum Foil?
Yup, your lasagne is actually eating holes in the metal. (No reflection on your cooking.) Aluminum is what chemists call an active metal, easily attacked by acids such as the citric and other organic acids in tomatoes. In fact, you shouldn’t cook tomato sauce or other acidic foods in aluminum pots because they can dissolve […]
Why Does the Label On My Cream Cheese Package Say It Contains No Calcium?
If you’ll pardon the double negative, cream cheese doesn’t contain no calcium. In the jabberwocky world of food labeling, zero is not the same as none. When you come right down to it, there’s no such thing as a zero amount of anything. All anyone can say is that the amount of something is too […]
How Does MSG Enhance Flavors In Food and How Is MSG Made?
It certainly does sound mysterious that these innocent-looking fine, white crystals with no really distinctive taste of their own should be able to boost the inherent flavors of such a wide variety of foods. The mystery lies not in whether MSG really works, nobody doubts that, but in how it works. As is the case […]
Why Does Vanilla Make Food Smell and Taste So Good, But Tastes So Awful From the Bottle?
Vanilla extract is around 35 percent ethyl alcohol, which has a harsh, biting flavor. Whiskeys and other distilled beverages contain even more alcohol, of course (usually 40 percent), but they are lovingly produced by time-honored flavoring and aging processes that soften the harshness. “Pure vanilla extract,” in order to be labeled as such, must be […]
What Is the Difference Between Tartar Sauce, Cream of Tartar, and Steak Tartare?
The words tartar and tartare come to us from two different directions. “Tartar” or “Tatar” was the Persian name for Genghis Khan’s horde of Mongols who stormed through Asia and Eastern Europe in the Middle Ages. The Tartars were viewed by Europeans as being, shall we say, culturally challenged, or at the very least politically […]
What Is Sour Salt and Where Does Sour Salt Come From?
Sour salt is misnamed. It has nothing to do with table salt or sodium chloride. In fact, it isn’t a salt at all; it’s an acid. They’re two different classes of chemicals. Every acid is a unique chemical having properties that distinguish it from all other acids. But it can have dozens of derivatives called […]
What Is Baking Ammonia and What Is Baking Ammonia Used For?
Ammonia itself is an acrid-smelling gas, usually dissolved in water and used for laundry and cleaning purposes. But baking ammonia is ammonium bicarbonate, a leavening agent that when heated breaks down into three gases: water vapor, carbon dioxide, and ammonia. It isn’t used much anymore , if you can even find it, because the ammonia […]
How Does Aluminum Cause Alzheimer’s Disease?
Sodium aluminum sulfate and several other aluminum compounds are listed by the FDA as GRAS: Generally Regarded as Safe. About twenty years ago, one study found increased levels of aluminum in the brains of deceased Alzheimer’s victims. Ever since then, suspicions have been circulating that aluminum, whether in food or water or dissolved from aluminum […]
How Do Brita Water Filters Work and Do They Remove Fluoride From the Water?
The name “water filter” is misleading. The word filtered literally means only that the water has passed through a medium containing tiny holes or fine passageways that screen out suspended particles. When traveling in a country whose water supply is suspect and you ask a waiter whether the water is filtered, an affirmative reply may […]
What Is the Difference Between Pasteurized Milk and Ultra Pasteurized Milk?
Back in 1986, during a six-month residence in the South of France, I saw something I had never seen in the U.S. The supermarkets kept their milk on the shelves without refrigeration. Instead of bottles or cartons, it was packaged in brick-shaped, cardboard-like boxes. How can they do that, I wondered. Granted, milk is not […]
How Is Homogenized Milk Made and What Does Homogenized Mean?
Some of my older readers may remember milk delivered to the doorstep in bottles. I’ve read about it in my history books. The milk had a separate layer of cream at the top. Why? Because cream is just milk with a higher proportion of butterfat and, because fat is lighter (less dense) than water, it […]
Does Heavy Cream Weigh Less Than Light Cream?
Heavy cream contains a higher percentage of milk fat (usually called butterfat, because butter can be made from it) than light cream does: 36 to 40 percent fat in heavy whipping cream versus only 18 to 30 percent in light cream. And, if you’re interested, the heavy cream can contain up to twice as much […]
Why Do Ramen Noodles Contain So Much Sodium and Fat Per Serving?
The ingredients in the noodles and in the package of flavorings are listed separately, so you can easily find out which contains what. The salt (usually lots of it) is in the flavorings. You might not expect the noodles to contain fat, but surprisingly, that’s where most of it is hiding. I know you’ve always […]
How Do Those Nonstick Nonfat Cooking Sprays Work?
There is no such thing as a nonfat edible oil. Fats are a family of specific chemical compounds, and an oil is just a liquid fat. Nor do the sprays have to contain a substitute for oil, because, are you ready?, they are oil. Those handy little cans, so great for coating baking pans and […]
What Is the Best Way to Dispose of Used Cooking Oil and Fat?
While edible fats and oils are ultimately biodegradable, they can gum up the works in a landfill for years. They’re not as bad as petroleum oils, however, which are digestible by only one or two species of bacteria and stay around essentially forever. Small amounts of fat can be absorbed in a couple of paper […]
What Are the Smoke Points of Common Vegetable Oils?
I don’t think you mean boiling point, because in spite of the poetic and sadistic appeal of the expression “boiled in oil,” oil doesn’t boil. Long before it becomes hot enough to think about bubbling, a cooking oil will decompose, breaking down into disagreeable chemicals and carbonized particles that will assault your taste buds with […]
How Do They Get Corn Oil Out of Corn?
They use a lot of corn. Corn is indeed a low-fat food, containing about 1 gram per ear until you slather it with all that butter. But it is by far the biggest crop in the United States, grown in 42 states to the tune of more than 9 billion bushels per year. Nine billion […]
Why Does European Butter Taste Better Than American Butter?
European butter has more fat. Commercial butter is 80 to 82 percent milk fat (also called butterfat), 16 to 17 percent water, and 1 to 2 percent milk solids (plus about 2 percent salt if salted). The United States Department of Agriculture (USDA) sets the lower limit of butterfat content for American butter at 80 […]
What Is Clarified Butter Used For?
Clarifying butter gets rid of everything but that delicious, artery-clogging, highly saturated butterfat. But when we use it in sautéing instead of whole butter, we avoid eating the browned proteins, which could also be unhealthful because of possible carcinogens. Name your poison. Some people think of butter as a block of fat surrounded by guilt. […]
How Come the Amounts of Fat on Food Labels Don’t Add Up?
All fats fall into three categories. Saturated, polyunsaturated, and monounsaturated fats. I had never noticed the funny arithmetic you mention, but as soon as I received your question I ran to my pantry and grabbed a box of Nabisco Wheat Thins. Here’s what I saw in the Nutrition Facts panel for the amounts of fat […]
Where Does Partially Hydrogenated Vegetable Oil Come From?
Oils are hydrogenated, that is, hydrogen atoms are forced into their molecules under pressure to make them more saturated, because saturated fats are thicker, more solid and less liquid, than unsaturated fats. The hydrogen atoms fill in hydrogen-poor gaps (Techspeak: double bonds, which are more rigid than single bonds) in the oil molecules, and that […]
What Makes Fats Turn Rancid?
Free fatty acids. That is, fatty acid molecules that have been broken off from their fat molecules. Most fatty acids are foul-smelling and bad-tasting chemicals, and it doesn’t take much of them to give a fatty food an off flavor. There are two main ways in which the fatty acids can become disconnected: the fat’s […]