Kaipen is dried, deep-green sheets of an algae called “kai” in Laotian (sometimes spelt “khai” in English.)
It’s made from freshwater algae, so it’s not seaweed, and therefore not as salty as seaweed, and has no fishy notes.
The algae is harvested November through to February. It is let dry, then is mixed with tamarind juice, then spread and pounded out thinly to form sheets on palm mats.
Then, it is sprinkled with chopped green onion, garlic, galangal, sesame seed, and thinly sliced tomato, and let dry in the sun.
It is used as a flavouring ingredient in soups and rice dishes, or as a vegetable, or as a wrapper for roasted ingredients.
It can be fried up in pieces as chips.
Flour is made from the sheets ground with rice.
Kaipen was originally made in Laos.
Substitutes
Nori