Cooking for Geeks - Real Science, Great Hacks, and Good Food

Cooking

Learn through curious experimenting and have fun while cooking. Do not be afraid to make mistakes. Take time to taste things, both to adjust seasoning and taste changes during the cooking process. Resist the urge to stir and poke, let the food cook.

Recipes

Read the whole recipe before starting and understand each step. The order of ingredients in a recipe indicates the order they are added to the dish. Know from the beginning where you want to end up.

Pull up a couple of examples and ask yourself what makes the recipe work. Look at four variations and average ratios of common components. To learn how an ingredient changes the taste. Replace half of one component of the recipe with the new ingredient and compare the taste. Then replace the whole component and compare again.

Temperature

Cooked is time times temperature. The most important variable in cooking is the temperature of the food itself, not the temperature of the container. Measure temperatures not time.

Add flavor and aroma with browning reactions. The Maillard reaction turns foods brown and generates mostly pleasant volatile aromatic compounds. When you toast bread to golden-brown.

Caramelization is the result of the breakdown of sugars. Pure sucrose caramelizes at between 160–204˚C with only the middle range of 180–188˚C generating rich flavours. Its aromas can be overpowering. Brownies are baked at the low range.

Between 82–88˚C most starches gelatinize. They can then be broken down easily by your digestive system.

Alcohol does not entirely burn off in cooking. 75% remains after flaming. 10% remains after 2 hours of simmering.

Temperatures of common reactions in food

See Women World, Time and Temperature (part 1) - Heat Transfer and Doneness.

Cooking meat

Many meats are roasted at or above 160˚C to cause the Maillard reaction. Most people prefer meat cooked such that myosin is denatured but actin is kept native (under 65.6˚C). The ideal piece of red meat has a thin outer crust cooked to over 155˚C and the inside at just over 57˚C. this requires a high temperature gradient between the crust and inside. Meat colour is inconsistent with doneness as it changes with pH.

Regions that bear more weight have higher levels of collagen. When collagen hydrolyzes it breaks into variously sized pieces and smaller pieces dissolve into the surrounding liquid creating gelatin and giving the distinctive mouthfeel to dishes like ox tail.

Temperatures required for various levels of doneness

Preserving

Wet brining adds flavour and reduces water loss during cooking. Food safety guidelines consider salt solutions of 6% sufficiently safe when curing fish. Excessive salt makes life non-viable. For an adult human, the lethal dose of table salt is about 80 grams — a restaurant salt shaker.

Sugar can also be used as a preservative and it works because there is little water activity.

Kitchen

Basic setup

  • Two sharp knives
  • Two pots
  • Two pans (ovensafe handles)
  • A spoon to stir (straight ends for corners)
  • A spatula to flip

Store equipment by its function.

Calibrate your oven using an oven thermometer and keep a pizza stone inside it to even heat distribution.

Pans

If you are going to splurge on something, get a Le Crueset Cast Iron pan. When searing pick the pan with maximum specific heat times mass so that it does not drop in temperature as much when the food is dropped in the pan. Do not leave pots and pans in water overnight. It will damage the finish. Avoid cooking acidic items like tomatoes in cast iron pans because they will react with the metal. Strainers can be used as splatter guards.

An upside-down cast iron pan under a broiler or wood-fired grill turns out delicious flat-crust pizzas.

Chopping

Use a diamond steel or whetstone to keep knives sharp. A butcher’s steel has to be harder than the knife you are using. Maintain the edge using two swipes on a steel every time you use it.

Plastic cutting boards can be sterilized in the dishwasher. Wooden chopping boards have been shown to reduce the likelihood of contracting salmonella, they can be cleaned with white vinegar.

Place a towel under the cutting board to prevent it slipping.

Ingredients

Picking the right ingredients for your dish is the biggest predictor of its success.

Freezing halts nutritional breakdown and preserves ingredients at their peak.

Use fresh herbs and grind spices.

Buy organic if you are going to eat the skin of a fruit, or if you buy dairy, eggs, and meats.

Proteins

Store raw meats below vegetables in the refrigerator to reduce the likelihood of cross-contamination. Meats should smell mild and perhaps a little gamey but never bad.

Fish should have little or no smell. Fish is extremely perishable. Decaying enzymes are more active than meat enzymes at fridge temperatures. Sashimi-grade fish should have been previously frozen to kill parasites.

Vegetables

Buy ingredients from the salad bar to save money and chopping. Fresh fruits should smell fragrant.

Lightly coat grilled vegetables with olive oil to prevent them drying out.

To cook vegetables in the microwave use a container with the lid mostly closed and with a small amount of water inside. The microwave will boil the water and the container will keep the steam in contact with the vegetables.

Always soak and boil beans because the protein phytohaemagglutinin must denature otherwise it will cause extreme intestinal distress.

The natural chemicals [in a cup of coffee] that are known carcinogens are about equal to a year’s worth of synthetic pesticide residues that are carcinogens. —Dr. Belitz et al. in Food Chemistry (Springer)

Food safety

Bacterial level is all about exposure — the amount of time and rate of multiplication at a given temperature. Cross-contamination in food preparation is the biggest danger. Wash hands with soap and hot water for at least 20 seconds and if you are sick do not cook at all for other people.

FAT TOM describes the six factors necessary for multiplication:

  1. Food (proteins/carbohydrates)
  2. Acidity (close to neutral)
  3. Temperature (mild)
  4. Time
  5. Oxygen
  6. Moisture

The FDA states that food should not be held between 4.4˚C and 60˚C for more than two hours. Keep serving spoons in the food so that they stay above 60˚C. Salmonella is killed when held over 58˚C for a sufficient period of time. Let food marinate in the fridge. Stick any leftovers in the fridge right away.

Normally the surface of food becomes contaminated. With steaming and pan frying, the surface is heated well beyond the temperature required to kill bacteria.

Wash can lids and the can opener before use. The blade picks up food while cutting through the lid.

Baking

Baking is about the details and cleanliness and organization are key to success. Measure with a digital scale instead of using measuring cups. Whisk dry ingredients together to make sure salt and baking powder are thoroughly blended.

Professional bakers use toothpicks to check doneness. They cannot tell the difference between natural and artificial vanilla.

Gluten is formed when two proteins, glutenin and gliadin, come into contact and form crosslinks through the kneading process.

Eggs

Crack eggs on the counter to prevent small pieces of shell.

Egg whites are the Styrofoam of the culinary world. Whisking egg whites turns them into a light airy foam by trapping air bubbles in a mesh of denatured proteins. Using an up-and-down circular motion catches and traps air.

Eggs whisked in a copper bowl are definitely easier to work with, but you can use Cream of tartar (18 teaspoon per egg white) in a stainless steel or glass bowl.

Dining

Tasting

The five basic taste components are:

  • Salt
  • Sweet
  • Sour
  • Bitter
  • Umami (savoury/meaty)

The intensity of primary tastes varies with the temperature both of the food and of the tongue. The ideal temperature is 35˚C. Bitterness is rejected by kids as it can indicate toxicity in nature. We learn to like it over time. Salt can neutralise bitterness.

We can discern ten thousand smells from the volatile compounds in a dish. Use alcohol to increase volatility — it lowers the surface tension and raises the vapor pressure. Artificial flavours miss hundreds of volatile compounds in the original ingredient, even if they have the ten most common.

Supertasters have more tastebuds. They find bitter, astringent, acidic and spicy foods to be stronger. A trained taster pays attention to sensations and can sort them. A good exercise is picking out a herb bottle and discerning the name. Cortisol dampens the stimuli strength of our taste buds.

Hosting

Minor touches like tablecloths and special plates communicate thoughtfulness. Simple appetisers like hummus and pita bread, olives and fruit show consideration. Always ask if your guests have any allergies. Manage expectations and perceptions — ship a fallen soufflé as a delicious chocolate cake.

Smaller plates lead you to eat 22% less than larger plates. If the serving pot is 2 metres away people are three times less likely to want seconds. Tall thin glasses causes you to drink 32% less than small wide glasses.

Wine

There should be structure of the beverage and the dish. The key variables in wine parings are:

  • Acidity
  • Tannins (if red)
  • Body or alcohol level
  • Sweetness
  • Flavour (kind of a bonus)

New World wines have more fruit expression, Old World have more earth and spice.


See also