BOGOTA — During the difficult months of the rainy season, when daily downpours put a damper on hunting and fishing, the Tatuyo indigenous people of Vaupés, in Colombia's Amazonian region, spend entire days in the jungle collecting fruit. The purpose of the forest harvest? To make yapurá.

A black paste with a pungent odor that rivals the smelliest of French cheeses, yapurá is a prized seasonal delicacy. It is also one of the stranger foods to be found in this part of the world.

The paste is obtained from the Erismus japura, a thick, 30-meter tall tree found in the Colombian departments of Guainía, Vaupés and Amazonas. The tree shares its name with the Japurá river, a major Amazon tributary that begins in Colombia (where it is known as the Caquetá) and flows deep into Brazil.

To prepare the paste, the Tatuyo people first cook the fruit and extract its oily seeds, which are then soaked (sometimes for days), cooked again, and finally crushed to make a fine blackish porridge. As the food is seasonal, the Tatuyo preserve the purée in a perfectly sealed hole in the ground — an underground pantry — near the fire, which keeps it from insects. It is served intermittently in the months before the next harvest season.

As the hole is not entirely air tight, the paste very slowly matures in the manner of a cheese, which enriches its flavor and creates the potent smell. It can be eaten alone or with such as the local fish broth. For those who can handle the smell, it's a true delicacy. But it's also as unknown to most people as it is difficult to come by — except, of course, for anyone willing to venture into Vaupés.