Ethylene and Fruit Ripening
Observe how ethylene gas speeds ripening and wilts flowers
| difficulty | beginner |
| time | 15 |
| hazard | low |
Food Chemistry Track
Edible experiments you can eat — proteins, emulsions, gels, browning, fermentation, and phase changes in the kitchen
The kitchen is the most familiar laboratory there is, and cooking is applied chemistry you can eat. This track works through the big themes that recur across recipes: proteins unfolding and re-networking, emulsions holding oil and water together, gels trapping liquid in polymer meshes, browning reactions that build colour and flavour, fermentation, and phase changes. Learn to see the mechanism and you can troubleshoot — and improvise — any recipe.
The chemistry
Almost everything in the kitchen is built from three families of molecule — proteins, carbohydrates (sugars and their polysaccharide chains), and fats — and cooking is the art of rearranging them. Proteins unfold (denature) under heat, acid, or whipping and re-link into new networks: curds, custards, and meringues. Carbohydrates caramelise, gel, and ferment. Fats carry flavour and, with an emulsifier’s help, hold hands with water in an emulsion.
A handful of cross-cutting phenomena recur again and again: colloids1 and emulsions (one substance finely dispersed in another), gels (a liquid trapped in a solid polymer mesh), the Maillard reaction and caramelization (the browning that builds savoury and sweet flavour), fermentation (microbes doing the chemistry for us), and phase changes2 governed by effects like freezing-point depression. Spot which one a recipe leans on and you can predict, fix, and reinvent it.
A short history
Humans practised sophisticated food chemistry long before they could explain it: cheese, bread, beer, and pickles are all ancient acts of controlled protein coagulation and fermentation. The science caught up slowly — Louis-Camille Maillard described the sugar–protein browning reaction that bears his name in 1912, though its full complexity is still being unravelled. In the late 20th century Hervé This and Nicholas Kurti coined molecular gastronomy, bringing laboratory rigour — and spherification, sous-vide, and foams — into the kitchen and making explicit what good cooks had always known by feel.
The experiments
Recommended order: start with Kitchen Emulsions (mayonnaise, butter, vinaigrette) and protein denaturation (cheese, ceviche, meringue, milk plastic) — the two ideas behind an enormous range of dishes. Build networks in Kitchen Gels and cross into physics with Instant Ice Cream. Bring in living chemistry via yeast fermentation and ethylene ripening, then finish with the heat chemistry of caramel, Maillard and honeycomb and the polymer cross-linking of spherification.
Sugar & Heat: Caramel, Maillard & Honeycomb
Brown sugar two different ways — pure caramelization versus the Maillard reaction — and aerate molten sugar into honeycomb candy with baking soda
| difficulty | intermediate |
| time | 30 |
| hazard | moderate |
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Where this leads
Food chemistry is a friendly doorway into the rest of the site. The acid that curdles cheese and sets jam is the Acid–Base track at the dinner table; the emulsifiers in mayonnaise are the same surfactants that clean in the Cleaning & Surfactants track; rock candy and ice cream are the solubility and phase behaviour of the Crystals & Solutions track; and apple browning is an enzyme-driven redox reaction. The natural pigments that make colour-changing drinks are explored in Natural pH Indicators.
Footnotes
Colloid — A mixture in which very small particles are dispersed through another substance without dissolving.↩︎
Phase-change material — A substance that stores and releases heat as it melts and freezes at a fixed temperature.↩︎