Kluwak nuts (Buah kluwek)

Buah kluwek refers to the seeds of the kepayang tree (lat. Pangium edule), native to the mangrove swamps of Southeast Asia, particularly Indonesia, Malaysia, and parts of Papua New Guinea.

These seeds are well-known in Indonesian and Malaysian cuisines for their unique flavor and are a key ingredient in traditional dishes such as rawon, a Javanese black beef soup, and certain types of Indonesian and Malaysian curries. The raw seeds of the buah kluwek are toxic due to their content of hydrogen cyanide.

To make them safe for consumption, they undergo a fermentation process. This involves burying the seeds in ash, banana leaves, or soil for more than a month, which significantly reduces their toxicity levels. After fermentation, the seeds are then boiled and sun-dried, making them safe to eat.

The use of buah kluwek in cooking imparts a deep, earthy flavor and a rich, black color to the dishes. The seeds are typically cracked open, and the fermented flesh inside is used as a spice or flavoring agent. The unique taste is often described as similar to that of chocolate or coffee, with a slightly bitter and smoky aroma.