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Flavour Science

principle

Also: flavour, chemistry, umami, maillard, caramelisation, browning

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Examples from your kitchen

The chemistry and physics behind why food tastes the way it does. Understanding these mechanisms unlocks improvisation and troubleshooting.

Key mechanisms

Maillard Reaction

Requires two components: a carbohydrate molecule (free sugar or from starch) and an amino acid (free or in a protein chain). They react to form an unstable intermediate that cascades into hundreds of by-products — nitrogen- and sulphur-containing ring molecules (pyrroles, pyrazines, thiazoles, thiophenes) that produce the cooked flavour of bread crusts, chocolate, coffee, dark beer, and roasted meat. Maillard flavours are more complex and meaty than caramelisation because nitrogen and sulphur from the amino acids add new aromatic dimensions.

Temperature: Begins around 280°F/140°C in dry conditions. Requires dry heat. The surface of food cooked in water or steam cannot exceed 212°F/100°C, so it will never reach Maillard temperatures. This is why braised or steamed food is pale and mild compared to grilled or fried food, and why searing before a braise creates essential flavour that the liquid phase cannot.

Practical consequence: Dry the surface of meat before searing. Any surface moisture keeps the surface temperature at 212°F until it evaporates — suppressing Maillard and creating steam instead of crust.

Caramelisation

Pure sugar browning — does not require amino acids. Becomes noticeable at ~330°F/165°C (about 100°F above Maillard onset). Produces sour organic acids, bitter derivatives, fragrant volatile molecules, and brown polymers. Flavour: sweet → acidic → bitter with increasing heat. Distinct from Maillard in character: caramel is simpler, less meaty, more confectionery.

High-sugar ingredients (mirin, maple syrup, honey) caramelise fast in a hot pan. The line between caramelised (good) and blackened (bitter, acrid) is narrow — reduce heat slightly if a glaze starts to darken past the desired point.

Fat Rendering

Solid fat melts out of tissue during cooking. In long braises, renders into the braising liquid, adding body, richness, and fat-soluble flavour compounds. Wagyu's extreme marbling renders abundantly; its fat is itself flavourful. See meat-science for how fat contributes to perceived tenderness as well as flavour.

Collagen to Gelatin

Collagen (the protein in connective tissue) begins dissolving into gelatin at 160°F/70°C, given sustained time at that temperature. Gelatin produces the glossy sauce and the melting succulence of a good braise. See braising and meat-science for the full temperature table.

Acid Balance

Vinegar, citrus, and fermented ingredients (rice vinegar, gochujang, mirin) brighten flavour and cut richness by contrast. In a glaze: the sour element is structural, not optional. Acid can also weaken muscle tissue and improve water retention in marinades (though penetration is slow and surface sourness is a risk with prolonged marinating).

Salt

Draws moisture, seasons deeply over time (dry brining). In a braising liquid, salt from soy + salted stock accumulates as liquid reduces — taste late, not early.

Umami

Glutamates from soy, aged cheese, fish sauce, mushrooms, tomato, MSG, seaweed. Amplifies other flavours and creates a mouth-coating depth. See umami for full treatment including MSG and wakame.

Herb and Spice Flavour Chemistry

Plant aromatics divide into two families with different thermal behaviour (see herbs-and-spices for full treatment):

  • Terpenes (volatile: limonene, linalool, menthol) — fresh, citrusy, floral; evaporate with heat. Add terpene-dominant herbs (basil, parsley, coriander, fresh dill) late or off heat.
  • Phenolics (heat-stable: eugenol, thymol, cinnamaldehyde, carvacrol, vanillin) — intense, defining; survive and integrate with heat. Add phenolic-dominant herbs (thyme, oregano, clove, cinnamon, bay) early.

Fat extracts what water cannot. Many aromatic compounds are fat-soluble. Briefly sautéing spices in oil or butter before adding liquid is the primary extraction step, not incidental flavour-building. Simmering in water alone misses a significant fraction of the aroma.

Pungency is pain, not flavour. Capsaicin (chilli), piperine (black pepper), gingerol/shogaol (ginger), and isothiocyanates (mustard, horseradish) activate TRPV1 pain/thermal receptors — the same receptors that respond to heat above ~107°F/42°C. They do not interact with taste buds. Capsaicin is fat-soluble; dairy (not water) neutralises chilli heat.

The Four-Element Balance (Korean / East Asian framework)

A glaze or marinade that hits all four — hot, sweet, salty, sour — will always taste complete. Missing one creates a flat, one-dimensional result. This logic is explicit in korean-cuisine and implicit in most good sauce-making.

Resting and Juice Retention

Cutting meat immediately after high heat causes significant juice loss — the fibres are contracted and can't reabsorb. Resting under loose foil allows fibres to relax and retain moisture. Critical on lean cuts (pork loin, chicken breast) where there is no fat buffer.

Related

bbq-technique · braising · umami · korean-cuisine · seasoning · fermentation

2026-05-14 — Late dinner, three ingredients, ten minutes.

2026-05-01 — First karaage with potato starch instead of plain flour — the crust is unrecognisable from what I was making before.

Sources