Cooking encyclopedia Food science
Also called browning reaction
The reaction between amino acids and reducing sugars that browns food and creates hundreds of new flavour compounds.
140โ180 ยฐC (284โ356 ยฐF)
It is not one reaction but a cascade. Amino acids and sugars combine, rearrange and fragment, building colour and aroma molecules that were not in the raw ingredient at all. Roast meat, bread crust, coffee, chocolate, toasted nuts and fried onions all taste of it.
It needs a surface above roughly 140 ยฐC, which means a dry surface: while water is boiling off, the surface is pinned near 100 ยฐC and cannot get there. It goes faster in alkaline conditions, which is why a pinch of bicarbonate speeds up onion browning and why pretzels are dipped in lye.
Any time you want a cooked ingredient to taste of more than itself.
Confusing it with caramelisation, which is sugar alone; expecting it in a wet pan; pushing it past brown into black, where the new compounds are bitter rather than savoury.
Meridian cooking encyclopedia โ Watchman Productions