Keep black cumin seeds in an airtight container, away from sunlight, heat and moisture. A cool kitchen cupboard is usually enough. Whole seeds retain their aroma considerably longer than ground black cumin, so grind only as much as you need.

Black cumin is usually used whole. Lightly toasting the seeds for a few seconds brings out their nutty, peppery aroma, but take care not to burn them. They can also be sprinkled directly over breads, stuffed vegetables, curries, pickles and savoury snacks.

Black cumin seeds contain naturally occurring plant compounds, oils and antioxidants. They are traditionally valued in several food and herbal traditions and are sometimes studied for their antioxidant and anti-inflammatory properties. As a food ingredient, however, the amount normally used in cooking is small. Black cumin should therefore be enjoyed primarily as a flavourful spice rather than treated as a replacement for medical treatment or prescribed medicines.

Black cumin has been cultivated and used for centuries across parts of the Mediterranean, West Asia and South Asia. Kew records Nigella sativa as native from Romania through western and southwestern Iran, with the plant later spreading to many other regions, including India. Its aromatic seeds have traditionally been used to flavour foods such as bread.

In India, black cumin is closely associated with kalonji, appearing in pickles, vegetable preparations, breads and regional spice combinations. It is also familiar in Middle Eastern and Central Asian cooking, where the tiny black seeds are used to add fragrance and character to baked foods and savoury dishes.

Black cumin has travelled well beyond the region where Nigella sativa originated. As the spice moved through trade and culinary exchange, different cultures found their own uses for its distinctive seeds. Today, it can be found in Indian pickles and breads, Middle Eastern baking, South Asian cooking and a variety of modern spice blends. Kew records the plant as introduced across a wide range of countries, including India.

Black cumin isn't actually cumin. Despite its common name, it belongs to the Ranunculaceae family, the same broad plant family that includes buttercups. Its small black seeds have also collected a surprisingly large number of common names, including black cumin, black fennel and kalonji, which can make spice shopping unnecessarily confusing.

For the best flavour, buy whole black cumin seeds rather than pre-ground powder. Add them near the beginning of cooking when you want their aroma to infuse oil, or sprinkle them toward the end when you want their characteristic crunch and flavour to remain noticeable.