Kanten

Kanten is the jelly-like substance derived from red algae which has been frozen then dried. Also known as agar-agar or simply agar, it is used in many Asian desserts and is a vegetarian substitute for gelatin. The Japanese have been eating algae for centuries and utilized its jelly-like qualities in dishes long before kanten was identified. It’s thought to have been accidentally discovered in Japan by Mino Tarōzaemon in 1658. The legend goes that on a cold winter night, he discarded a bowl of algae soup outside and came back a few days later to find that it had solidified and dried up. Out of curiosity, he rehydrated it and found the texture and flavor more pleasing. Since then, many different algae have been tested for its gelling qualities but kanten is made with a blend of ogonori and tengusa algae. Nearly 50 years after its discovery, kanten appeared as an ingredient used for desserts for the first time in 1707.

Its discovery was arguably the most influential on yokan. Until then, yokan was made by mixing red bean an and flour then steaming it. But thanks to the discovery of kanten, a faster method of yokan called neri-yokan (練り羊羹) was developed. Neri-yokan is made by dissolving kanten with water, adding sugar and simmering it until it is dissolved, adding an to the mixture and cooking it to the desired consistency then pouring it out into a mold for it to set.

You can buy the algae itself and cook the jelly-like substance out but kanten can be bought in many convenient forms.

Block (full length, half length, cubes)

Block kanten are evenly weighed so there is no need to measure it out.
It requires rehydrating it in water from the day before.

String

String kanten are convenient when making smaller batches.
Like the block kanten, it requires rehydrating from the day before.
The result will have a harder texture than block kanten.

Powder

Powdered kanten comes in a range of coagulation textures.
It is most convenient as it can be used right away.

Kanten in powdered form is created in a factory so the coagulation texture, measured by how much weight a ㎠ can withhold, can be altered. The texture for powdered kanten can be adjusted between 60-2000g/㎠. (The toughest textures are used in petri-dishes.)

Differences between kanten and gelatin: