Anpan — soft Japanese buns filled with red-bean paste

i. Origin & history

Bread was a novelty in Japan when the country opened to the West in the mid-nineteenth century. The story of anpan begins with Kimura Yasubei, a former samurai who, after the Meiji Restoration ended the samurai class, opened a bakery in Tokyo in 1869 — the business that became Kimuraya. Western-style bread, raised with hop or beer yeast, was not much liked; it was dry and sour to Japanese palates and did not suit a rice-based diet.

Kimura and his son Eizaburō worked on a bread that would appeal. They replaced foreign yeast with sakadane, a starter based on the koji and yeast used in sake brewing, which gave a softer, sweeter, more fragrant dough, and they filled it with the bean paste already beloved in Japanese sweets. The result, sold from 1874, was anpan, and it was an immediate success.

The most often repeated chapter of the story came in 1875, when, through the statesman Yamaoka Tesshū, anpan was presented to the Meiji Emperor on a visit to the Mito residence. For the occasion Kimuraya pressed a salt-pickled cherry blossom into the centre of each bun — the origin of sakura anpan, still a Kimuraya speciality. The emperor's approval made anpan famous, and the bakery became a supplier to the imperial household. April 4 is now celebrated in Japan as Anpan Day.

Anpan established a whole category of Japanese breads called kashi pan — sweet breads — including melonpan, cream pan and jam pan. In 1969 the illustrator Takashi Yanase created Anpanman, a superhero whose head is an anpan that he feeds to the hungry; the character went on to become one of Japan's best-loved children's franchises.

ii. What makes the bread so soft

Anpan dough is an enriched dough — made with milk, egg, sugar and butter, which tenderise the crumb and give a fine, fluffy texture. Sugar and fat interfere with gluten formation and slow the staling of the starch, so the bread stays soft for longer than lean bread. Bread flour gives enough gluten to hold the shape around a heavy filling and to rise well.

Kimuraya still uses a sake-yeast starter, which gives a characteristic sweet, faintly alcoholic aroma, but instant yeast is used in most home and commercial versions. Many modern Japanese bakers also use a yudane or tangzhong — a portion of flour scalded with hot water or milk — which gelatinises the starch and lets the dough hold more moisture, producing an even softer, longer-lasting crumb. The recipe below includes a simple yudane.

The filling has to be stiff. A soft paste would flatten the bun and leak through the dough. Japanese commercial anko for bread is cooked down until it holds a ball, which is easy to wrap. The bun is pressed flat after shaping and given a dimple in the centre, which stops it doming into a ball and leaving an air gap between bread and paste.

The glossy brown top comes from an egg wash and a fairly hot oven. Baked quickly, the bun browns before the inside dries, keeping it soft.

iii. Ingredients

Makes 10 servings · scroll the side panel to adjust

• 20 g bread flour, for the yudane
• 40 ml boiling water, for the yudane
• 280 g bread flour
• 35 g caster sugar
• 5 g salt
• 5 g instant yeast
• 1 egg
• 130 ml lukewarm milk
• 30 g unsalted butter, softened
• 400 g red-bean paste (koshian or tsubuan)
• 1 egg yolk beaten with 1 tbsp milk, for glazing
• 1 tbsp black sesame or poppy seeds

Bread flour gives the right strength; a mix of half bread flour and half plain flour gives a slightly more tender bun. The yudane — flour scalded with boiling water — is optional but makes the buns noticeably softer and slower to stale. For the filling, koshian (smooth paste) is the classic; tsubuan (chunky) is equally traditional. Shop-bought paste must be thick enough to roll into balls; if it is soft, cook it in a non-stick pan for a few minutes, stirring, until stiffer. For sakura anpan, top each bun with a salt-preserved cherry blossom, rinsed and patted dry.

iv. Method

1. Mix the 20 g flour and 40 ml boiling water to a stiff paste. Cover and cool for at least 30 minutes. Divide the bean paste into 10 balls of 40 g and chill.
2. Combine the flour, sugar, salt and yeast. Add the egg, milk and cooled yudane, and mix to a shaggy dough. Knead for 5 minutes, add the butter and knead for another 8–10 minutes, until smooth, elastic and stretchy enough to pull into a thin sheet.
3. Cover and leave to rise in a warm place for 60–90 minutes, until doubled.
4. Knock back and divide into 10 equal pieces of about 55 g. Shape into balls and rest under a cloth for 10 minutes.
5. Flatten each piece into a 10 cm disc, thinner at the edges. Place a ball of bean paste in the centre, pull the edges up around it and pinch firmly to seal. Set seam-side down on a lined baking tray and press to flatten slightly.
6. Cover and prove for 30–45 minutes, until puffy. Heat the oven to 190 °C (375 °F), or 170 °C fan.
7. Brush with the egg glaze. Dip the end of a rolling pin or your thumb in flour and press a dimple into the centre of each bun, then sprinkle sesame or poppy seeds into the dimple.
8. Bake for 12–15 minutes, until deep golden brown. Cool on a rack; cover with a clean cloth while cooling to keep the crust soft.

v. Tips & common mistakes

• Knead until the dough is elastic. Under-kneaded dough tears around the filling. It should stretch into a thin, translucent sheet without breaking.
• Chill the bean paste balls. Cold, firm paste is easier to wrap and less likely to smear onto the seal.
• Seal tightly and keep the seam clean. Any paste on the edges stops the dough sticking, and the bun opens in the oven.
• Press the dimple firmly. It keeps the bun flat and stops an air gap forming between bread and paste.
• Do not over-bake. At the deep golden stage the buns are done; extra minutes dry the crumb.
• Cover while cooling. A cloth traps steam and keeps the crust soft and shiny, as in Japanese bakeries.

vi. Variations

Sakura anpan is topped with a salted cherry blossom and sometimes filled with white bean paste mixed with sakura. Koshian anpan and tsubuan anpan differ in the paste; Japanese bakeries often mark them with poppy and sesame seeds respectively. Shiro-an pan uses white bean paste, kuri anpan adds chestnuts, and matcha anpan flavours dough or filling with green tea. An-butter buns, filled with bean paste and a slice of cold butter, are a modern favourite.

Anpan sits among other bean-paste breads and pastries: the Chinese red bean bun is steamed, the Korean bungeoppang is a fish-shaped waffle, and the Japanese monaka and daifuku enclose the same paste in wafer and mochi. The sweet-bread family it founded includes melonpan.

vii. Serving & storage

Anpan is eaten as a snack, breakfast or lunchbox treat, often with milk — the pairing of anpan and milk is a classic in Japan — or with green tea or coffee. It is best on the day it is baked, at room temperature.

It keeps for 2 days in an airtight bag at room temperature. Avoid the fridge: chilled bread stales faster, and refrigerated anpan becomes dry and firm within a day, though it remains safe for 3–4 days. To refresh, warm for 10–15 seconds in a microwave or for 5 minutes in a 160 °C (320 °F) oven. Anpan freezes very well for up to a month: wrap individually, then thaw at room temperature or reheat from frozen.

ix. More from Japanese

• Melonpan — buns with a cookie crust
• Red Bean Bun — Chinese steamed bean bun
• Daifuku — mochi with bean paste
• Monaka — crisp wafers with bean paste
• Bungeoppang — Korean fish-shaped pastry
• Yokan — red-bean jelly