DUKAI
The Ingredient Library

Vegetables

Garlic

Allium sativum

The bulb that starts most savoury cooking: pungent and sharp raw, sweet and mellow when roasted, and stored dry for months.

Also
Aglio
Family
Amaryllidaceae (onion family)
Young garlic plants with flat strap-like leaves growing in a garden bed

How to recognise it

In the garden and in the hand.

  • Young garlic plants with flat strap-like leaves growing in a garden bed
    growingThe plant: flat, keeled, strap-like leaves in two ranks.
  • A garlic flower head of small purple flowers and bulbils on a curving scape
    identifying featuresThe scape: a head of small flowers and bulbils on a curling stalk.
  • Freshly lifted garlic bulbs with white skins and green stems laid in a bunch
    harvestedHarvested: whole plants lifted for curing, bulbs still attached to their stems.
  • Two purple-streaked garlic bulbs, one broken open, with a peeled clove and an unpeeled clove in front
    preparedIn the kitchen: the bulb, the papery skin, the clove.
Growth habit
An upright plant sixty to ninety centimetres high, with flat strap-like leaves rising from a single underground bulb; hardneck types send up a curling flower stalk in early summer.
Leaves
Long, flat, grey-green, keeled leaves, folded along the midrib, arranged in two ranks.
Stem
A false stem of sheathing leaf bases; hardneck varieties produce a stiff woody flower stalk (the scape) that coils before straightening.
Flower
A round head of small pale pink or white flowers mixed with tiny bulbils, on the scape, usually removed to strengthen the bulb.
Colour
White to purple-streaked papery skins over cream cloves.
Aroma
Sulphurous and sharp when crushed; the smell is the identifier.
Texture
Firm, crisp cloves under papery skin.
Distinguishing features
A bulb made of separate cloves wrapped in papery skin, flat keeled leaves, and the unmistakable smell.
Common lookalikes
In the garden, leeks and onions have similar leaves; onions form a single bulb without cloves. In the wild, garlic-scented leaves of ramsons (Allium ursinum) are edible, but poisonous lily of the valley and autumn crocus leaves grow in the same places and do not smell of garlic.

CautionNever eat a wild plant on leaf shape alone; if it does not smell of garlic when crushed, it is not garlic.

In the garden

Growing and harvest.

Conditions
Full sun, rich, well-drained soil; planted as single cloves in autumn or late winter, harvested when the lower leaves yellow.
Season
Green garlic and scapes in spring; mature bulbs lifted in early summer, then cured and stored. Seasons vary by region and climate.
Harvested part
The bulb; also the green scapes and young whole plants.
Ready when
Lift when about a third of the leaves have yellowed; cure in a dry airy place for two to three weeks before storing.

In the kitchen

Flavour and use.

Flavour
Pungent and hot raw, sweet and nutty when roasted or slowly cooked; bitter if burnt.
Aroma
Sharp when raw and freshly cut; rounded and sweet once cooked.
Texture
Crisp raw; soft and creamy when roasted whole.
Edible parts
The cloves; the scapes; the leaves of young green garlic.
Preparations
Sliced or crushed into oil at the start of a dish, Roasted whole in the skin, Confited in oil, Pounded raw into aioli and pesto, Rubbed on grilled bread
Techniques
Sweating in oil, Roasting, Confit, Pounding, Infusing
Pairs with
Olive oil, Rosemary, Tomato, Lamb, Anchovy, Chilli
How Paul uses it
Garlic seasons the lamb in Agnello al rosmarino on the Recipes page and sits with the heirloom tomatoes and basil in the Portfolio photographs.

Selection and storage

Choosing, keeping, preserving.

Choosing
Firm, heavy heads with tight dry skins and no green shoots or soft cloves.
Storage
Whole heads in a cool, dry, airy place for months; not in the fridge, which encourages sprouting. Peeled or cut cloves in the fridge for a few days.
Preserving
Confit in oil and kept refrigerated, roasted and frozen, pickled, or fermented into black garlic. Home-made garlic in oil must be refrigerated and used within days (see safety).

Traditional uses, nutrition and current evidence

What is known, and how well.

Each statement carries its evidence level in words and a numbered source. Nothing here recommends an ingredient as a treatment.

Nutrition

  • Established nutritional fact

    Garlic is eaten in small amounts; a clove contributes little energy and small quantities of manganese, vitamin B6 and vitamin C. Its character comes from sulphur compounds formed when the clove is crushed. [1] [2]

Traditional use

  • Traditional use, not clinically established

    The European Medicines Agency's herbal monograph records garlic bulb preparations as traditional herbal medicines for the relief of cold symptoms and as an adjunct to diet for the prevention of atherosclerosis. These are traditional-use registrations, not proof of efficacy. [3]

Current evidence

  • Supported by human research

    Meta-analyses of randomised trials report that garlic supplements modestly lower blood pressure in people with hypertension and modestly lower total cholesterol. The trials used standardised supplements over weeks to months, not garlic in food, and the effects are small; garlic is not a treatment for either condition. [4] [5]

Safety and cautions

Before you cook with it.

  • Garlic in food is safe for most people; large raw amounts can cause heartburn, wind and body odour.
  • Garlic supplements can increase bleeding risk with anticoagulant and antiplatelet medicines and may interact with some HIV and other drugs; anyone on such medication should discuss supplements with their clinician. Ordinary culinary use is not the concern.
  • Home-made garlic stored in oil at room temperature can support the growth of Clostridium botulinum, the cause of botulism. Keep garlic-in-oil refrigerated and use within a few days, or freeze it.
  • Allergy to garlic exists and can also appear as contact dermatitis on the hands of cooks who handle it constantly.

This ingredient profile is provided for culinary and general educational purposes. It is not medical advice and does not recommend an ingredient as a treatment. Anyone who is pregnant, managing a medical condition, allergic, or taking medication should consult an appropriate healthcare professional before using concentrated herbal preparations or supplements.

Elsewhere on DUKAI

Also in the library

Sources and review

  1. 1USDA FoodData Central, Garlic, rawNational food-composition database
  2. 2National Institutes of Health, Office of Dietary Supplements, Vitamin C fact sheetGovernment health agency
  3. 3European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Allium sativum L., bulbus (EMA/HMPC/7686/2013), 2017.Medicines regulator
  4. 4Ried K. Garlic lowers blood pressure in hypertensive individuals, regulates serum cholesterol, and stimulates immunity: an updated meta-analysis and review. Journal of Nutrition. 2016;146(2):389S-396S.Peer-reviewed meta-analysis
  5. 5National Center for Complementary and Integrative Health (NIH). Garlic: usefulness and safety.Government health agency

Sources reviewed 9 September 2026. Culinary and general educational information.

Photograph credits