The essence of the belostomatid beetle, known in Vietnamese as ca cuong, is a Vietnamese condiment used to gently perfume fish sauce (nuoc mam) and remove some of the fishiness. It smells like soft perfume, says phan1—similar to jasmine or rose water. It’s hard to believe this floral liquid comes from a beetle! Actually, most modern ca cuong available on the market is synthetic, though it’s chemically identical to the beetle extract, says septocaine_queen. You can probably buy it in a good Asian supermarket—look for a clear liquid in a bottle with a dropper. Only a few drops are necessary to mellow out an entire portion of nuoc mam.
Board Link: Help identifying a Vietnamese ingredient!