After a meal in any traditional Indian home or restaurant, you will be offered a small dish of saunf — roasted fennel seeds, sometimes coated in sugar or mixed with other mouth-freshening seeds. The practice is ancient and purposeful: fennel is one of Ayurveda's most effective post-meal digestive aids, and the ritual of eating a small quantity after eating is one of the most sensible food customs in any culture.
It belongs in your chai too.
What Fennel Actually Does
Fennel seed (Foeniculum vulgare) contains three primary active compounds:
Anethole — the dominant volatile compound responsible for the characteristic aniseed flavour. Anethole has documented antispasmodic properties, meaning it relaxes the smooth muscle of the digestive tract. This is the mechanism behind fennel's effectiveness for bloating, cramping, and irritable bowel symptoms.
Fenchone — a secondary compound with mild digestive stimulant properties. Fenchone increases bile secretion from the gallbladder, which improves fat digestion and reduces the heaviness after rich meals.
Estragole — present in small quantities; has antimicrobial activity against several gut bacteria associated with gas production, which partly explains fennel's anti-bloating effect.
The Clinical Evidence
A 2016 randomised trial published in the Italian Journal of Pediatrics found that fennel seed oil emulsion significantly reduced infantile colic symptoms — its safety and effectiveness in one of medicine's most resistant populations suggests a strong pharmacological basis for the effect.
For adults, a 2014 study in the Journal of Gastrointestinal and Liver Diseases found that a combination of fennel and curcumin was significantly more effective than placebo for irritable bowel syndrome symptoms including cramping, bloating, and irregular bowel movements.
Multiple smaller studies confirm anethole's antispasmodic effect in smooth muscle, which is the mechanism of action for most digestive symptoms.
How to Use Fennel in Chai
The fennel seed should be gently bruised before adding to the brewing liquid — a quick press with the back of a spoon or a brief moment in a mortar releases the volatile compounds more effectively than whole seeds.
Add 1/4 to 1/2 teaspoon of fennel seeds along with the other spices, at the start of the water phase. Simmer for the full spice time before adding milk. The flavour contribution is subtle — aniseed-adjacent but much lighter than star anise — and blends harmoniously with cardamom and ginger.
The fennel-cardamom-ginger base is the standard North Indian digestive chai blend, drunk specifically after heavy or oily meals. It is the most intelligent post-meal digestive aid that costs less than ten pence per cup.
“Fennel has been settling digestion for five thousand years. The modern gastroenterology literature is catching up. In the meantime, add the seeds to the pot.