The truth about garlic, a loved and loathed ingredient

When I was at primary school, a classmate gave me a yellow boiled sweet, which looked delicious. I sucked it happily until the lemony outer layer dissolved to expose a horrid core of garlic. It was a joke sweet, bought from a toyshop. The experience was so awful that I can still remember it vividly.

Back then, English people were just warming to the possibilities of garlic, which had previously been seen as a dubious French food, its proper context a garland of bulbs hanging round the neck of a beret-toting Frenchman. (The stereotype arose from the “Onion Johnnies”, Bretons who cycled around Britain selling strings of onions from their bikes.) Garlic bread was coming into fashion and my mother, an adventurous cook, often used garlic at home. But garlic has always been a divisive flavouring, both loved and loathed, delicious in certain contexts, repulsive in others.

Allium sativum or “cultivated garlic” is the bossy ringleader of the allium family, which includes more than 1,000 recognised species of onion, garlic and leek. Its name is derived from Old English gar (spear) and leac (leek), a reference to its narrow, pointed leaves. While varieties of wild garlic are still found in many places, like the ramsons flowering across Britain in spring, the “cultivated” fat-bulbed type is thought to have evolved in central Asia or the eastern Mediterranean. It was already important in the diets of people in ancient Egypt and classical Greece and Rome: garlic bulbs were found in Tutankhamun’s tomb. According to Chinese legend, it was brought into China by the Han dynasty envoy Zhang Qian some 2,000 years ago. One of its old Chinese names was hu suan or “barbarian” garlic, a reference to its foreign origins, and the Chinese still call it “big garlic” (da suan) because it is larger than native varieties.

Different types of garlic have bulbs and cloves of different sizes, skins that can be white, pink or purple and varying levels of pungency. In general, new garlic is milder, while older, drier garlic is more aggressive. All alliums owe their pungency to sulphurous compounds that lie dormant until their flesh is cut, bruised or chewed. In garlic, this damage brings the enzyme alliinase into contact with a substance called alliin, which it breaks down into what food science expert Harold McGee calls “chemical weapons” — the sulphurous, eye-watering compounds that were designed to ward off predators. (They work equally well against lovers and, some would say, vampires.) These compounds irritate cells in and around the mouth and nose, and can cause pain, McGee writes in Nose Dive: A Field Guide to the World’s Smells. Some of the substances are extremely reactive and go on to form other sulphurous compounds after the initial bust-up, which is why garlic has such a complex, evolving flavour.

Garlic has since antiquity been a folk remedy and prophylactic in many cultures. Labourers and Jewish slaves in ancient Egypt were fed garlic, apparently with the intention of building their strength and making them more productive. Hippocrates, the Greek physician often referred to as “the father of medicine”, prescribed garlic for pulmonary and other complaints, and as a purgative.

Much later, in the 17th century, the English doctor Nicholas Culpeper wrote in his Complete Herbal that garlic “was anciently accounted the poor man’s treacle, it being a remedy for all diseases and hurts . . . It provoketh urine and women’s courses, helpeth the biting of mad dogs and other venomous creatures; killeth worms in children, cutteth and voideth tough phlegm, purgeth the head, helpeth the lethargy, is a good preservative against, and a remedy for any plague, sore or foul ulcer.” Culpeper did warn, however, that because of its hotness it could exacerbate anger and give the melancholic “strong fancies” and “strange visions”. There was wisdom in at least some of these applications: modern scientific studies have indicated that garlic has antibacterial effects and may help to prevent and treat certain cancers, heart problems and high blood pressure.

Whatever its health benefits, garlic does have an intensely physical, meaty, animal odour. It shares some of its volatile sulphur compounds with human urine, durian fruit, asafoetida, rotten eggs and smelly cheeses, according to McGee, with one in particular, diallyl disulphide, giving garlic its “signature” aroma. One of its by-products ­“circulates in the blood and persists on the breath for hours no matter how well we wash or brush our mouth”, says McGee. Swallowing garlic raw and neat in hopes of preventing a cold, for example, can be frighteningly awful, producing not only foul breath but a burning sensation in the digestive tract, which is why pharmacists now sell it in ­capsule form.

Garlic was already controversial in the classical world: the Roman poet Horace condemned it as “more harmful than hemlock” and said it would drive a lover away. In ancient China, it was one of the strongly flavoured vegetables that people were obliged to shun, along with meat, when fasting before important sacrificial rites or while in mourning. After Buddhism entered China from India, Chinese monks abstained from eating garlic and other alliums while meditating because of the distracting physicality of their smells. Later Buddhist texts suggested it could also inflame carnal passions. The absence of garlic and other alliums, as well as meat, fish and poultry, became the signature of Buddhist temple cooking in China — in Mandarin, the word hun describes both these unclean vegetables and foods derived from animals.

As a rule, those unaccustomed to garlic have always loathed it. Lord Macartney, who led ­Britain’s first diplomatic mission to China in 1793, described the locals undiplomatically as “foul feeders and eaters of garlic and strong-scented vegetables”. In The Yangtze Valley and Beyond from 1900, the traveller Isabella Bird, while impressed by the “enormous variety” of the Chinese diet and by “cleanly cooking and wholesome and excellent meals”, objected to the “prevalent flavour of garlic”. The bulb “well applied”, she said, “is an excellent condiment, but it is startling to meet with it in unexpected places . . . Onions, garlic, leeks, ­scallions and chives are consumed by both rich and poor, and it is seldom possible to be out of their odour.”

Garlic has always been a divisive flavouring, both loved and loathed, delicious in certain contexts, repulsive in others

Despite Bird’s comments, there has often been a class dimension to views on garlic. Alan Davidson notes in The Oxford Companion to Food that while in ancient civilisations it was eaten by the masses, upper classes often disdained it because of its smell. In the Middle Ages, according to Colin Spencer’s British Food, peasants grew and ate garlic, onions and leeks, but “there was a suspicion that these vegetables belonged to the poor and should not grace a lord’s table”. The 17th-century food writer John Evelyn banned garlic from his salads due to its “intolerable rankness” and wrote that it should be kept for rustic types.

In China, garlic is used relatively little in elite culinary traditions, such as the banquet cooking of Jiangnan and the Cantonese south, but enthusiastically in the street food and folk cooking of many regions. When I stayed with a farming family in rural Gansu province, their daily diet consisted mostly of noodles, dumplings and breads, with few vegetables and very little meat, but there were always pots of chilli and chopped garlic on the table to season the food and, presumably, to provide vital vitamins and minerals.

The more you break garlic up, the more chemical reactions are triggered and the more potent the flavour. This is why whole garlic is odourless, sliced garlic is punchy and crushed garlic is a frenzy of flavour. In European culinary traditions, some uses seem expressly designed to prevent garlic from overpowering a dish: for example rubbing a cut clove around a salad bowl or over some toasted bread or, as the Italians do, sizzling a smacked clove in olive oil to extract a trace of its perfume before discarding it. In other preparations, the intensity of garlic seems to be softened by incorporating it in a smooth, oily sauce, as with aïoli Provençal, Spanish allioli and Greek skordalia.

Acidity subdues the intensity of garlic, according to McGee. This may explain why so many Chinese dipping sauces combine chopped garlic with vinegar. Sweet pickled garlic is an essential accompaniment for the famous Xi’an dish, stewed mutton with soaked flatbreads (yangrou pao mo). Muted by their pickling, the garlic cloves function, if not exactly as a palate-cleanser, then certainly as a refreshing counterbalance to the richness of the meat. Northern Chinese also steep aged garlic in vinegar to make laba garlic, traditionally in the last lunar month, the pickling process triggering a chemical reaction that turns the cloves an electrifying blue-green.

The spikiness of raw garlic is also tamed by cooking, which neutralises the enzymes responsible for its fiercest flavours and produces an array of sweet and meaty odours (as long as you don’t burn it, which makes it bitter). When you sniff the air above the wok as you sizzle chopped garlic in oil at the start of a Chinese recipe, you are witnessing a suite of chemical reactions in which unstable sulphur compounds react with one another, producing new flavours and smells. The same applies to the initial sizzling of pounded spice pastes in Indian and south-east Asian cuisines.

In particular, the sweetness of cooked garlic comes from chains of fructose sugars in the cloves that break down with slow cooking. Snails in garlic butter, practically radioactive with garlic before cooking when raw, are calmed and sweetened when broiled in hot butter. A joint of lamb spiked with garlic and anchovies becomes luxuriously fragrant in the oven. The most dramatic example of the way heat quells the fires of raw garlic is the southern French recipe for a whole chicken roasted with 40 cloves, which soften within their skins and can then be squeezed out and mixed with the juices of the bird. The chef Raymond Blanc suggests simply roasting garlic cloves on their own and spreading the contents on toast. And of course there’s the recently fashionable black garlic, created by keeping garlic in controlled conditions of heat and humidity for weeks or even months until it caramelises and can be eaten like toffee.

The Chinese are unusual in eating so many forms of garlic. While foragers and trendy chefs in Europe and America may eat wild garlic in season, and occasionally the long green scapes or stems of cultivated garlic, most westerners only consume it in clove form. But in China, garlic stems are a common ­vegetable, delectable when stir-fried with strips of cured pork or fresh seafood, the kiss of heat giving them a juicy sweetness. Garlic shoots or green garlic (suanmiao or qingsuan), a variety harvested in autumn and winter that looks like a cross between a spring onion and leek, is a traditional ingredient in many Sichuanese dishes, including twice-cooked pork and Mapo tofu. The Sichuanese also grow solitary garlic (dusuan), a local variety with a single, purple-skinned bulb instead of a cluster of individual cloves. One old-fashioned dish involves a braised fish surrounded on the serving platter with a line of these tiny bulbs, like a string of pearls.

The takeover of the world by strong and dramatic flavours seems an inexorable part of historical progress. The European desire for spices in the Middle Ages drove trade and colonialism. After Columbus “discovered” the Americas, the chilli conquered many parts of Africa, India, China and south-east Asia, and is now making further inroads into the western world. Garlic, once shunned by the English, is now hard to avoid in the British Isles and seems to be increasingly accepted worldwide. As Davidson remarks with characteristic humour in The Oxford Companion to Food: “It is coming close to complete penetration of the kitchens of the world. And, if folklore is correct, its spread must be bringing ever closer the extinction of the vampire.”

Fuchsia Dunlop is the winner of the 2022 Guild of Food Writers’ Food Writing Award

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