For some Indonesians, you must be familiar with kluwek. However, many of you may be hearing about it for the first time.
Kluwek, the seed of the picung fruit, is a typical Indonesian spice commonly used in soupy dishes such as rawon and soto konro. Outside Indonesia, kluwek is also popular in Malaysia and Singapore for Peranakan dishes such as ayam buah keluak.
Keluak, or kluwek, is an important ingredient in Indonesian cuisine, giving it a rich flavor and distinctive black color. These seeds come from the large fruit tree known as picung (Pangium edule), which bears fruit in an 8-9 month cycle. The name for keluak varies from region to region, such as kluwek, keluak, pangi, or kepayang.
According to Kemendikbud.go.id, the seeds of the picung fruit, or kluwek, contain high levels of cyanide in the form of cyanogenic glycosides. This compound releases cyanide acid when damaged, posing a danger when consumed fresh.
Allegedly, this keluak poison was once used to coat arrows for hunting or warfare purposes.
Why Is It Safe to Consume Kluwek?
Kluwek can be consumed after undergoing a processing method that eliminates cyanide from the picung fruit flesh. This process involves rotting the picung seeds, boiling them, soaking or rinsing them in water for three to five days, and then burying them in ashes for 40 days.
Even after processing, it's important to test keluak before use.
There are two ways to ensure that kluwek is safe to use as a cooking seasoning. First, shake the kluwek as you would an avocado; if the seed separates from the skin, it's safe to use. Second, taste the kluwek; if it's not bitter, it's safe for cooking. If it still tastes bitter, it may still contain cyanide.
Safe-to-eat kluwek is shiny black and odorless. Remember to avoid kluwek with open shells, as they may be contaminated with poison.
