The Maillard reaction can occur with all methods of cooking, or even at room temperature. The pH level, the water content and the temperature of the food all influence the speed of the reaction and directly influence the aromas that are released. The same foodstuff will therefore produce different aromas depending on whether it is grilled, roasted, fried, boiled or even steamed in a pressure cooker. Food with a high pH (alkaline) provides more favourable conditions for the reaction to take place than food with a low pH (acidic). A marinade, for example, alters the pH of food and, consequently, how it will brown and the aromas it develops during cooking.
At 90°C, the Maillard reaction is rather slow. To speed things up, the surface of the food needs to rise above the boiling point of water (100°C). At temperatures above 115°C, the reaction speeds up and, from 130°C, it takes place very quickly. However, above 180°C, the Maillard reaction stops. Another chain of chemical reactions then commences, called pyrolysis, the decomposition of food by heat. Pyrolysis causes the ‘burnt’ bitter taste of food that has been grilled too much, and the black, charred substances, which are potentially carcinogenic.