Ziaulhaq Ahmadi sits on the floor of his small, one-story house, a brown, mud-walled compound at the end of a dusty alley in Aqa Saray. Surrounded by vineyards, fruit trees, and snow-capped mountains, the village is a half hour’s drive north of Kabul, Afghanistan’s capital. With great gentleness, he taps on what looks like a sealed mud bowl until it cracks open.

Ahmadi, 45, reveals a handful of grapes from inside the mud container. They have been there, he explains, since harvest time, nearly five months ago, and kept for Nowruz, the Persian New Year, which is celebrated on the spring equinox. After all these months, his grapes still look perfect, and are perfectly fresh.

A proud smile forms on his wrinkled face. “We use an ancient preservation technique,” he says.