What Einstein Told His Cook

1. Flavor is a Chemical Symphony of Smell and Taste

What we call flavor is a combination of odors that our nose detects and tastes that our taste buds detect, with additional contributions from temperature, pungency (the “sting” of spices), and texture (the structure and feel of the food in the mouth).

Flavor's complexity. Our perception of flavor is a sophisticated interplay between smell and taste, heavily weighted towards the olfactory sense. The nose can distinguish thousands of odors, contributing an estimated 80% to flavor, especially as gaseous molecules travel from the mouth to the nasal cavity during chewing and swallowing.

Taste's limited palette. Compared to smell, our sense of taste is relatively simple, traditionally recognizing only four primary tastes: sweet, sour, salty, and bitter. Modern science adds umami (savory) to this list, associated with compounds like MSG. Taste buds, primarily on the tongue, respond to molecules dissolved in liquid.

Sweetness reigns supreme. Among the primary tastes, sweetness is universally favored, often associated with energy-rich foods like ripe fruits. This preference is deeply ingrained, influencing not only our food choices but also our language, using "sweet" to describe pleasant experiences.

2. Sugar: Refined Doesn't Mean Unhealthful

White sugar is just raw sugar with those other materials removed.

Sugar's origin. Sugar, a generic term for carbohydrates like sucrose, comes primarily from sugar cane and sugar beets. Raw sugar, produced at the mill, contains impurities and is refined to varying degrees to produce different types, including the familiar white granulated sugar.

Refinement is purification. The refining process removes non-sugar components, primarily molasses, leaving behind pure sucrose. Claims that refined white sugar is inherently unhealthful compared to brown or "raw" sugars are nonsensical; the difference lies mainly in flavor and color imparted by residual molasses, not nutritional superiority.

Sugar types and uses. Different sugars have different properties. Powdered sugar contains cornstarch to prevent caking, making it unsuitable for cold liquids. Superfine sugar, with smaller crystals, dissolves easily. Brown sugar hardens when it loses moisture, a problem solved by storing it in airtight containers or using quick fixes like microwaving.

3. Salt: More Than Just Flavor, Often Misunderstood

Common salt—sodium chloride—is probably our most precious food.

Salt's vital role. Salt (sodium chloride) is essential for human health and has been used for millennia as a nutrient, flavor enhancer, and preservative. Its saltiness is one of our fundamental taste sensations, though other salts like potassium chloride also taste salty.

Myths debunked. Many common beliefs about salt are scientifically unfounded.

• Adding salt to pasta water primarily enhances flavor, raising the boiling point negligibly.
• Raw potato does not absorb excess salt from soup; it merely soaks up salty liquid.
• "Freshly ground salt" offers no flavor advantage over granulated salt, only textural difference.

Salt varieties. Different salts exist, but their chemical composition (mostly NaCl) is key.

• Specialty salts (popcorn, margarita) differ mainly in crystal size/shape.
• Sea salt, while often prized, is largely purified NaCl; its "mineral richness" is nutritionally insignificant, and its unique properties often stem from crystal shape, not origin.
• Kosher salt is named for its use in koshering meat; its coarse, irregular crystals are ideal for this and for pinching, preferred by chefs for control.

4. Fats: Understanding the Building Blocks and Their Behavior

Every molecule of fat incorporates three molecules of fatty acids.

Fat's structure. Fats are primarily triglycerides, molecules composed of glycerol bonded to three fatty acids. Fatty acids are chains of carbon atoms, classified as saturated, monounsaturated, or polyunsaturated based on their hydrogen content. These fatty acids determine the fat's properties.

Properties and uses. The type of fatty acids influences whether a fat is solid (more saturated, like animal fats) or liquid (more unsaturated, like vegetable oils) at room temperature.

• Hydrogenation makes oils more saturated and solid (e.g., margarine), but can create trans fatty acids.
• Clarifying butter removes water and solids, raising its smoke point for higher-temperature cooking.
• Cooking oils have varying smoke points, the temperature at which they break down and burn, which is crucial for frying.

Rancidity and spoilage. Fats turn rancid through hydrolysis (breaking down into free fatty acids) or oxidation, accelerated by heat, light, and metals. Proper storage in cool, dark places and limiting reuse of cooking oil are essential to prevent rancidity and the formation of unhealthful compounds.

5. Kitchen Chemicals: Common Compounds Explained

It’s a threadbare cliché that cooking is chemistry.

Beyond ingredients. Our kitchens are full of chemicals beyond the basic nutrients. Water filters use activated charcoal and ion exchange resins to remove impurities, odors, and tastes, but generally not fluoride.

Leavening agents. Baking soda (sodium bicarbonate) is a single chemical that reacts with acid to produce CO2 gas for leavening. Baking powder is baking soda mixed with a dry acid, often double-acting to release gas both when wet and when heated. Recipes may use both to balance acidity.

Common compounds.

• Aluminum compounds in baking powder are considered safe; scientific evidence does not link aluminum ingestion to Alzheimer's.
• Baking ammonia (ammonium bicarbonate) is an old leavening agent that produces ammonia gas, sometimes leaving a bitter taste.
• Sour salt is not a salt but citric acid, used for tartness.
• Cream of tartar (potassium hydrogen tartrate) is a salt of tartaric acid, used to stabilize egg whites.

6. Meat and Fish: Different Structures, Different Cooking

There is virtually no blood in red meat.

Meat color. The color of meat comes primarily from myoglobin, an oxygen-storing protein in muscle, not blood. Red meat (beef) has more myoglobin than white meat (pork, poultry breast). Cooking turns myoglobin brown.

Meat tenderness. Meat tenderness is affected by aging (breaking down connective tissue) and cooking methods. Collagen in connective tissue breaks down into gelatin when heated, contributing to tenderness and juiciness, especially in cuts near the bone.

Fish vs. Meat. Fish cooks faster than meat due to structural differences. Fish muscles have shorter, thinner fibers and less connective tissue (collagen) than land animals, making them naturally more tender and quicker to cook. Fish also spoils faster due to different proteins, enzymes, and higher unsaturated fat content.

7. Heat: The Energy That Transforms Food

To boil off even a small amount of water requires a surprising amount of heat energy.

Energy and calories. A calorie is a unit of energy, not just heat. Food calories measure the energy released when food is metabolized. Different foods provide different caloric densities (fat has 9 cal/g, protein/carbs have 4 cal/g).

Boiling water. Water boils when its molecules gain enough energy to escape as vapor, fighting atmospheric pressure. At higher altitudes, lower pressure means water boils at lower temperatures. Adding salt slightly raises the boiling point, but negligibly for cooking speed. Covering a pot helps water boil faster by trapping heat and steam.

Cooking methods. Different methods transfer heat differently.

• Conventional ovens heat air, which then heats food (slow, inefficient).
• Grilling uses high direct heat, causing browning reactions (Maillard) and vaporizing dripping fat for flavor. Charcoal and gas grills differ in heat distribution and flavor compounds.
• Reducing liquids takes time because converting liquid water to vapor requires significant energy.

8. Cold: Preserving and Preparing with Low Temperatures

The quickest method of all, I now reveal, is to place the unwrapped frozen food on an unheated, heavy skillet or frying pan.

Freezing basics. Freezing food involves converting its water content into ice crystals, making the food hard. Defrosting melts these crystals.

Defrosting methods.

• Air thawing is slow and risks bacterial growth on the surface.
• Soaking in cold water is faster than air, as water conducts heat better.
• Placing frozen food on a heavy metal pan is fastest, as metal is an excellent heat conductor, drawing heat from the room into the food.

Freezing effects. Freezing can affect food quality.

• Raw whole eggs may crack shells and yolks can become gummy due to gelation.
• Freezer burn occurs when water molecules migrate from the food's ice crystals to colder surfaces (like freezer walls) through permeable packaging, leaving the food dry and discolored. Using proper, airtight wrapping prevents this.

9. Microwaves: A Revolutionary, Often Feared, Cooking Method

It is the first new way of cooking in more than a million years.

Microwave mechanism. Microwave ovens use electromagnetic waves (microwaves) generated by a magnetron. These waves cause polar molecules, primarily water, to flip rapidly, generating heat through molecular agitation, not friction.

Heating process. Microwaves penetrate food only about an inch, heating the outer layers. Heat then transfers inward by conduction and steam diffusion. Standing time or stirring is needed for heat to distribute evenly and avoid hot/cold spots.

Safety and myths.

• Microwaves do not make food radioactive or change its fundamental molecular structure beyond cooking.
• Modern ovens have minimal leakage; the metal screen on the door blocks microwaves.
• Metal should generally not be put in microwave ovens as it reflects waves and can spark or melt due to induced currents.
• "Microwave safe" containers don't absorb microwaves but can get hot from the food.
• Heating water can cause superheating and sudden eruption if not heated to a vigorous boil.

10. Tools: Science in Your Hands, From Pans to Peelers

Today’s cooks, like other artists, have their own figurative palettes and paintbrushes in the form of an arsenal of equipment that makes old tasks easier and new tasks possible.

Cookware science. Frying pans should distribute heat uniformly and respond quickly to temperature changes, depending on thickness and material conductivity.

• Silver and copper are excellent conductors but expensive.
• Aluminum is a good conductor and lighter, often anodized or clad with stainless steel.
• Stainless steel is a poor conductor, often used as cladding or in layered pans.
• Cast iron is thick and retains heat well but is slow to heat and a poor conductor.

Knife storage. Magnetic racks do not damage knife blades; they may even slightly stiffen them. Damage usually results from carelessly hitting the blade against the rack. Proper sharpening is key for safety.

Cleaning and preparation.

• Pastry brushes (soft, natural bristles) and basting brushes (stiffer, synthetic) are designed for different tasks and heat levels. Proper washing prevents gumminess.
• Olive oil sprayers use pressure to create a fine mist, unlike standard spray bottles.
• Rolling and microwaving lemons/limes before hand-squeezing significantly increases juice yield by breaking cells and reducing juice viscosity.
• Mushrooms do not absorb significant water when washed; washing is fine despite common lore.

11. Beverages: Liquid Chemistry, From Fizz to Proof

Beverages are foods in the liquid state.

Coffee and tea. Coffee acidity contributes to flavor, not bitterness (caffeine is bitter). Espresso may contain less total caffeine than a large cup of regular coffee, depending on brewing method and bean type. Decaffeination methods are safe, removing caffeine without significantly altering flavor compounds. Real tea comes from one plant; "herbal teas" are tisanes.

Carbonation. Soft drinks contain carbon dioxide dissolved in water, forming carbonic acid for fizziness and tartness. Phosphoric acid is added to some colas for extra tang. Belching CO2 from beverages is negligible compared to fossil fuel emissions. Plastic bottles can lose carbonation over time due to gas permeability. Keeping soda cold helps it retain fizz.

Alcohol. Alcohol content in beverages varies. "Moderate consumption" is defined by grams of alcohol (approx. 15g for women, 30g for men daily), not arbitrary "drinks." Alcohol content labeling on beer varies by state law. "Non-alcoholic" beer contains less than 0.5% alcohol by volume. Cooking with alcohol does not remove all of it; some remains depending on cooking time and method.

Last updated: July 12, 2025