Kohakuto Jewel Candy and Kanten Confections

Japan, traditional wagashi lineage; kanten (agar) introduced from China via Nagasaki in the 17th century; kohakuto as a specific crystallised sugar-kanten confection formalised in the Edo period; modern artisan revival from 2015 onwards

Kohakuto (琥珀糖), meaning 'amber sugar', is a Japanese confection made by setting kanten (agar-agar) with sugar syrup, then allowing the outer surface to dehydrate and crystallise over several days, producing a jewel-like gem with a shimmering crystalline exterior and a soft, yielding interior reminiscent of jelly. The contrast between the crunchy crystallised shell and smooth inner gel is the defining textural experience. The name kohakuto originally referred to amber-coloured pieces (琥珀, kohaku = amber), but the contemporary confection encompasses all colours — the crystal-growth process produces translucent gems in any colour achieved with natural or artificial colouring, and artisan producers create pieces resembling amethysts, tourmalines, and sea glass. Making kohakuto requires precision: kanten is hydrated and dissolved, sugar added at ratios that govern crystal formation (roughly 350–400g sugar per 4g kanten), and the mixture poured into moulds or piped into shapes, set, then dried at room temperature for 3–5 days until the exterior crystallises. Flavours mirror seasonal wagashi — matcha green tea, sakura cherry, yuzu citrus, plum — and pieces are sized for one or two bites. The confection became a social media sensation in 2016–2018 due to its photogenic crystalline appearance, driving a revival of artisan kohakuto production and international interest. Traditional applications are simpler: kanten-based sweets including mitsumame (kanten cubes in sugar syrup with azuki, mochi, and fruit) and anmitsu (the same with added red bean paste) are the direct relatives.

Sweet, clean, and flavoured by additions (matcha, yuzu, plum, sakura) rather than the kanten itself, which is neutral; the texture — crystalline-crunchy exterior yielding to soft, translucent interior — is the primary sensory event