Ajwain

Ajwain is a delicate, feathery annual herb of the carrot family, about 60 to 90 cm tall, with umbrella-shaped clusters of tiny white flowers. The seeds, which are really small dry fruits, are oval and ridged, about 2 mm long, grey-green to light brown, and often still carry tiny stalks.

Raw seeds smell strongly of thyme with a hint of anise and taste hot, sharp and bitter, which mellows with cooking or dry roasting. They are sold whole, as ground powder, as thymol-rich essential oil, and as ajwain water used in traditional preparations. Because the flavour is intense, a little goes a long way.

The exact origin of Trachyspermum ammi is debated, with the Eastern Mediterranean, Egypt and South Asia all proposed, and the plant has been cultivated for centuries in India, Iran, Afghanistan, Pakistan and Egypt. India is the largest producer today, with Rajasthan and Gujarat major growing areas.

The name ajwain comes from Hindi and Urdu, related to the Sanskrit yavani. The English name carom likely derives from a South Asian language term, and bishop's weed is a name shared with related Apiaceae plants. The genus name Trachyspermum is Greek for rough seed.

Ajwain has been used in South Asian food and medicine for a very long time. The seed appears in classical Ayurvedic writings under names related to yavani, where it is described as a digestive and carminative. In Indian homes, a pinch of roasted ajwain with salt or in warm water is a common remedy for indigestion and a post-meal digestive.

The spice travelled across the Middle East and North Africa, where it appears in Egyptian and Ethiopian cooking, including in some spice mixes. In Ethiopia and Eritrea, it is called nech azmud and is used in berbere-like blends and in flatbread, while Persian and Afghan cooks use it in breads and pickles.

In the 20th century, ajwain became important as a source of thymol, which was extracted for antiseptic, mouthwash and pharmaceutical products. It is cultivated commercially in India for both the spice and thymol markets. Today it remains a pantry staple in Indian kitchens, appearing in snacks, flatbreads and pickles, and has gained notice among chefs worldwide.

Ajwain is tempered in hot oil or ghee to flavour lentils, vegetables and curries, and is mixed into parathas, puris, namak para, pakora batter, savoury biscuits and breads. It is traditionally paired with beans and lentils, partly for its reputation of easing gas.

It is also made into digestive tea, chewed with salt after meals, and used in pickles and chutneys. In traditional medicine it is used for stomach discomfort, and its thymol-rich oil is used in some oral care and rubs.

Ajwain seed contains an essential oil dominated by thymol, which has antimicrobial and antispasmodic activity in laboratory studies. It is traditionally used for digestion, and some small studies suggest benefit for indigestion or cough, but high-quality clinical trials are lacking. In everyday culinary amounts, it is a flavourful spice with a long safe history, but evidence does not support using it as a treatment for disease.