concentrated flavourings derived from a range of ingredients, from flowers to fish to pure chemicals. Broadly speaking, an extract is any substance separated from a more complex mixture by physical or chemical means. Many foods and drinks are extracts in this sense, including sea salt, sugar, oils, coffee and tea, and meat stock.
Traditional food extracts fall into two groups: those which concentrate the flavour of intrinsically appealing ingredients, and those which create concentrated flavour from unremarkable ingredients.
Extracts of spices, herbs, and flowers are produced by processes that remove and concentrate their aromatic essential oils. The most popular flavouring in the West is vanilla extract, made by macerating vanilla beans in a mixture of water and alcohol. Rose ‘water’ produced by distillation of the petals has long been an important ingredient in Arab cuisines; almond and mint are other common distilled extracts. The finest citrus oils are simply pressed from the rinds of the fruit.
A second group of extracts provides both aroma and an intense taste. These qualities result from production processes that break down animal or plant tissues to liberate their chemical building blocks—notably savoury glutamic and other amino acids, and sugars—and then transform these building blocks in flavour-enriching browning reactions. Meat extracts are made by cooking meat and bones in water to remove their soluble components, and boiling down the liquid to concentrate it and speed the browning reactions. Fish sauce is the product of salting and fermenting fish in a closed container for months. Fish enzymes and microbes break the tissues down into their building blocks, which then slowly react to develop flavour and colour. Traditional soy sauce is made from soybeans and wheat by a complex process involving roasting, fermentation, and maceration, and gets its flavour from salt, high-temperature browning reactions, and prolonged microbial action. Yeast extracts, including Marmite and Vegemite, start with microbes themselves as the primary ingredient. The yeast enzymes digest their own cells into components that react during the water extraction and cooking down.
Macerated and distilled plant extracts have been made since the time of the earliest Mesopotamian cities, and Asian fish and soy sauces go back 2,000 years and more. Flavour concentrates of all kinds are well suited to large-scale manufacturing, and are important ingredients in the modern food industry. Some are now entirely artificial approximations of traditional extracts, manufactured from a small handful of pure chemical precursors.
Harold McGee is the author of On Food and Cooking: The Science and Lore of the Kitchen, whose two editions have won several awards, and The Curious Cook: More Kitchen Science and Lore.
