Overview

Agar is a gelatinous substance extracted from red algae (Rhodophyta), primarily from genera such as Eucheuma and Gracilaria. It is flavorless, odorless, and sets into a firm, heat-stable gel. Agar is used across many cuisines as a vegan alternative to gelatin and as a textural ingredient in desserts, jellies, and savory preparations.

Origin and history

Agar was first documented in Japan in the 17th century, where it was produced by freezing and thawing seaweed to extract the gelling agent, a process called kanten [1]. The name “agar” comes from the Malay word agar-agar, meaning jelly, reflecting its use in Southeast Asian cooking [2]. By the late 19th century, agar was introduced to Western science as a solid culture medium for microbiology, replacing gelatin because it resists degradation by bacteria [1].

Varieties and aliases

  • Kanten (Japanese): the traditional Japanese name for agar, often sold in dried bar or powder form [3].
  • Agar-agar (Malay/Indonesian): the full name used in Southeast Asia.
  • Gulaman (Filipino): the Tagalog term for agar, used in desserts and drinks [2].
  • Eucheuma and Gracilaria: the primary seaweed genera from which agar is commercially extracted.

Culinary uses

Agar is dissolved in hot liquid and sets upon cooling to form a firm, brittle gel. In Japanese cuisine, kanten is used to make yokan, a dense jellied confection of sweet red bean paste and sugar [3]. In the Philippines, gulaman is cut into cubes and added to sago’t gulaman, a chilled drink with sago pearls and brown sugar syrup [2]. In Russian and Soviet confectionery, ptichye moloko (bird’s milk) uses agar to create a stable soufflé center for cakes and candies [4]. Agar is also used in molecular gastronomy for spherification and gelification.

Cross-cuisine context

Agar functions as a direct analogue to gelatin (derived from animal collagen) but with a higher melting point and firmer set. In Japanese cuisine, kanten is a foundational ingredient in wagashi (traditional confections), comparable to how gelatina is used in Latin American desserts but with a different texture and thermal behavior. In Filipino cuisine, gulaman is a staple in both drinks and desserts, bridging the role of gelatin in Western sweets and the seaweed-based jellies of East Asia [2].