Alkali is a basic substance with a pH above 7 in aqueous solution. In cooking, alkaline ingredients can change the colour, texture, flavour and browning of food. Common culinary examples include baking soda (sodium bicarbonate), food-grade lye (sodium hydroxide) and alkaline mineral salts used in specific regional preparations.
Alkalinity changes the chemical environment of food. It can accelerate browning, alter plant pigments, influence protein behaviour and affect the texture of doughs and noodles. The result depends on the specific alkali, its concentration, the food and the cooking method.
Acids have a pH below 7 and tend to lower the pH of a preparation. Alkalis raise pH and can produce different effects on colour, texture and browning. Both are used deliberately in culinary processes, but they are not interchangeable.
Only use food-grade alkaline ingredients in the concentrations specified by a tested recipe or process. Strong alkalis such as sodium hydroxide are caustic and can cause serious burns; use appropriate protective equipment and follow supplier instructions. Never substitute household cleaning products for food-grade ingredients.
Chef’s tip: Small changes in pH can have a large effect on colour and texture. Weigh alkaline ingredients accurately and test the result before scaling a formula.
Key distinction: Alkali describes a chemical property; it is not one specific ingredient or a synonym for baking soda.
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