Can India's 5,000-year-old disposable clay teacups compete with single-use plastic?

A kulhad is a biodegradable, disposable clay cup used in India by food vendors to serve hot beverages like chai and some desserts like yogurt. The cups have been excavated from the Indus Valley as far back as the end of the Stone Age, 5,000 years ago. They are generally unglazed and unpainted, so the hot liquid seeps into the clay, which is said to affect the flavor of the beverages, giving them a more earthy flavor.

Lately, synthetic materials like plastic and paper have started replacing these clay cups, as they are cheaper and more convenient for vendors to acquire. But the clay cups still persist in India. Their cost varies, but it generally sits around 1 rupee, or $.01, apiece.

Each kulhad is made by hand in harsh conditions that take a significant toll on the artisans. But proponents point to kulhads as the healthier, more environmentally friendly option, though the science isn't all there.

We went inside a kulhad workshop outside Kolkata to see how the traditional clay cup business is still standing.