Japan — yokan (originally a Chinese-derived sheep meat jelly, 羊羹) was adapted by Buddhist monks into a bean paste jelly. Mizu-yokan as a specifically higher-water summer version developed through the Edo period, particularly in Kyoto and Osaka.
Mizu-yokan (水羊羹, water yokan) is a summer wagashi — a softer, higher-water-content version of yokan (羊羹, traditional dense bean jelly) that is set with less agar and more water, producing a delicate, trembling, almost transparent jelly that serves as a cooling summer sweet. Where standard yokan is dense and shelf-stable, mizu-yokan is perishable, must be refrigerated, and is eaten cold — the extra water content and softer gel create a coolness-in-the-mouth sensation that is the point. Aichi Prefecture's Minokamo region is particularly known for mizu-yokan as a winter specialty (a regional anomaly — cold bean jelly in winter).
Mizu-yokan's primary flavour experience is textural-thermal: the cool, gently sweet, softly yielding gel dissolves smoothly on the palate. The azuki bean provides its characteristic earthy sweetness — subtle, roasted-grain quality — and the agar itself is neutral. The lightness of mizu-yokan compared to dense yokan means the flavour is less assertive but the cooling, refreshing quality is heightened. Served with unsweetened cold barley tea (mugicha), the combination is quintessentially Japanese summer.
The agar (kanten, 寒天) ratio: mizu-yokan uses roughly 50–70% of the agar content of standard yokan, combined with more water. Azuki bean paste (koshi-an, smooth strained) is the foundation — it must be very smooth and free of skins. The agar is dissolved in water over heat, then the bean paste is added and cooked together briefly. Seasoning: salt and sugar are adjusted — mizu-yokan should be less sweet than standard yokan to feel refreshing. Pour into wet moulds and refrigerate for at least 2 hours. The set should be firm enough to unmould but trembles when the plate is moved.
Seasonal flavour additions: summer mizu-yokan may include flavours like matcha (green tea mizu-yokan), yuzu zest, shiso, or fresh sweet corn — each reflecting the current season. The Minokamo (Aichi) tradition of eating mizu-yokan in winter (as a warming room contrasts with the cold jelly) is a specific regional quirk that reveals how food culture can invert seasonal conventions for specific historical and commercial reasons. Mizu-yokan in a glass instead of a ceramic dish creates a visual clarity that communicates the water content.
Using too much agar — the characteristic softness is lost and the result resembles standard yokan. Not straining the bean paste sufficiently — any skin fragments create textural irregularities in what should be silky-smooth. Over-sweetening — mizu-yokan's cooling quality is diminished by excessive sweetness. Not serving cold — room temperature mizu-yokan is soft but loses its refreshing character.
Japanese Cooking: A Simple Art — Shizuo Tsuji