Food Science
Why cooking works.
What heat, acid, salt, fat, sugar, time and microbes actually do to food — explained simply, with the temperatures that matter and experiments to try at home.
What happens as food heats up
- How proteins set when cooked 50–60 °C · Fish muscle proteins set; fish is moist and just opaque
- Starch gelatinisation 52–60 °C · Wheat starch starts to gelatinise
- The Maillard reaction 50–100 °C · Very slow browning (hours to weeks)
- Caramelisation from 110 °C · Fructose starts to caramelise
- Smoke point of fats 150–175 °C · Butter (milk solids brown, then burn)
Heat and cooking
- beginner · home experimentHow heat moves into foodHeat reaches food by conduction, convection and radiation, and how fast it arrives decides whether the outside overcooks before the inside is done.
- beginner · home experimentThe Maillard reactionBrowning between sugars and proteins that creates the savoury, roasted flavour of seared meat, toast, roasted spices and coffee.
- beginner · home experimentCaramelisationSugar breaking down under high heat into brown colour and bitter-sweet, buttery flavours, with no protein involved.
- intermediate · home experimentHow proteins set when cookedHeat, acid, salt and beating unfold proteins, which then bond together: this is why eggs set, meat firms and milk curdles.
- beginner · home experimentStarch gelatinisationStarch granules swell with water when heated, which is how rice softens, sauces thicken and batters set.
- beginner · home experimentEvaporation and reductionBoiling off water concentrates flavour, salt and body, which is how sauces, gravies and syrups thicken.
- beginnerSmoke point of fatsThe temperature at which a fat gives off visible smoke as it starts to break down; it varies widely with refining and use.
Ingredients and chemistry
- intermediate · home experimentAcids and bases in cookingAcidity and alkalinity change colour, texture, browning and rising, from bright green beans to fluffy dhokla.
- intermediate · home experimentEmulsionsFine droplets of one liquid held in another, such as oil in water, kept stable by emulsifiers like egg yolk and mustard.
- intermediate · home experimentGluten developmentWheat proteins form an elastic network when wetted and worked, giving bread its chew and soft roti its stretch.
- beginner · home experimentFats and oilsFats carry flavour, transfer heat, tenderise doughs and add richness; whether they are solid or liquid changes what they can do.
- beginner · home experimentEnzymatic browningCut apples, potatoes, brinjal and avocados turn brown because an enzyme reacts with air.
- intermediate · home experimentOxidation and rancidityOxygen slowly damages fats, aromas and some vitamins, making oils rancid and spices dull.
- beginner · home experimentMoisture and textureWhere water is, and how much, decides whether food is crisp or soggy, tender or tough.
- intermediate · home experimentHow sugar behavesSugar does far more than sweeten: it holds moisture, tenderises, browns, lowers freezing point and builds syrups and candies.
- beginner · home experimentSalt and osmosisSalt seasons, draws water out of cells, changes proteins so meat holds more juice and controls microbes in preserved foods.
- intermediate · home experimentAroma compounds and flavourMost of what we call flavour is smell: small volatile molecules that are released, transformed or lost depending on how we cook.
- intermediate · home experimentCapsaicin and pungencyChilli heat is a pain signal triggered by capsaicin, which dissolves in fat and alcohol rather than water and survives cooking well.
Fermentation and preservation
- intermediate · home experimentYeast fermentationYeast eats sugars and gives off carbon dioxide and alcohol, which raise bread and build flavour.
- intermediate · home experimentLactic acid fermentationLactic acid bacteria turn sugars into acid, souring and preserving yogurt, kimchi, sauerkraut, idli batter and many pickles.
- intermediateThe science of picklingPickles stay safe through acid, salt, low water and spices, whether the acid comes from vinegar or from fermentation.
- advancedThe science of curingSalt, sugar and often nitrite draw water from meat and fish, block harmful bacteria and give cured foods their colour and flavour.
- intermediate · home experimentThe science of dryingRemoving water stops microbes and slows enzymes, which is why dried chillies, papads, fruit and jerky keep for months.
- beginnerFood-safety temperaturesBacteria multiply fastest between 5 and 60 °C, so cook food hot enough, keep it out of that range and cool leftovers quickly.
Advanced food science
- advancedMolecular gastronomyThe scientific study of what happens to food during cooking, and the modernist techniques it helped bring into kitchens.
- intermediate · home experimentFoams and gelsFoams trap air in a liquid or solid; gels trap liquid in a network. Both depend on proteins or long-chain carbohydrates.
- advanced · home experimentHydrocolloids: thickeners and gelling agentsStarches, gums, pectin, agar, gelatin and seed mucilages hold water to thicken, gel or stabilise food.
- advancedSous-vide scienceCooking sealed food in a water bath at exactly the target temperature gives edge-to-edge doneness, with safety controlled by time as well as heat.
- intermediate · home experimentChanging texture: tenderising and crispingMechanical work, enzymes, salt, acid, alkali and heat all change how tough, tender, crisp or soft food is.
- advanced · home experimentCrystallisationHow sugar, fat and water form crystals, which decides whether fudge is creamy, chocolate snaps and ice cream is smooth.