Sweets
Koppa Mochi
Koppa mochi — sun-dried sweet potato pounded together with steamed mochi rice
Sweet potato is boiled, sliced, and sun-dried into "koppa," then pounded together with steamed glutinous rice and sugar into a mochi. Made at home as a keeping food in rice-poor Amakusa, it is said to have been prized as a New Year treat.
- Origin: Kumamoto Amakusa
- About 950 km west of Tokyo
What it's made of
A plain snack made by pounding 'koppa' — sweet potato sliced into rounds, boiled, then sun-dried — together with steamed glutinous rice and sugar. It has a soft, chewy texture, and is said to carry more sweetness from the sweet potato than eating it fresh would give. In the Amakusa region, where flat farmland is scarce, sweet potato, which grows even in poor soil, has long been widely cultivated.
How it's made
Peeled sweet potato is sliced into rounds about one to two centimeters thick, boiled, then sun-dried to make 'koppa.' This is pounded together with steamed glutinous rice and sugar, or starch syrup. It's eaten plain while still soft; once it hardens, people warm it in a microwave or toaster, or pan-fry it in butter. Dusting it with roasted soybean flour or deep-frying it are other traditional ways to eat it.
Why it took this shape
In the Amakusa region, where flat land was scarce and rice yields limited, sweet potato, which grows even in poor soil, is said to have long been widely cultivated. Making use of the way boiling and sun-drying concentrates more sweetness into 'koppa' than eating the raw potato would give, making it into a long-keeping New Year treat in individual households is thought to be behind how the snack took hold. Rounds of 'koppa' strung on straw and hung from the eaves are described as the sight that announces winter's arrival in Amakusa.
Before you go
- How to use a convenience storeA quick guide to choosing rice balls and hot snacks, buying coffee, paying by cash, IC card, or tap payment, using the eat-in corner, and sorting your trash — the basics for a first visit.
- How to shop in a depachika (department store food hall)A guide to browsing prepared foods and bento, choosing wagashi as a gift with a good shelf life, sampling etiquette, end-of-day discounts, asking for cold packs and wrapping, and finding your way around a depachika floor.
- Takeout and convenience store customsHow to answer "Shall I warm it up?", choosing chopsticks and a paid plastic bag, saying whether you'll eat in or take out, handling trash and eating while walking, and the different tax rate for takeout versus eating in.
Dishes in the same style
- Abekawa MochiFresh-pounded rice cake is dusted in soybean flour mixed with sugar. Named for the Abe River, it's said to have been famous among Tokaido travelers as a teahouse specialty and to appear in the travel novel Tokaidochu Hizakurige.
- Iga ManjuSweet bean paste is wrapped in rice flour dough, then coated with dyed sticky rice grains. One account ties the name to the grains' resemblance to a chestnut's spiny husk, and in the western Mikawa region it's said to be offered to Hina dolls at the Doll Festival.
Ingredients and dishes from this land
Also from Kumamoto
- Amakusa DaioA large-bodied meat fowl once kept in Amakusa in the Meiji and Taisho eras, said to have died out in the early Showa period before Kumamoto prefecture spent roughly a decade recreating it; reportedly among the biggest jidori breeds, shipped at 120–150 days.
- Gane-ageSweet potato cut into batons is coated in a ginger-sweetened batter and deep-fried. "Gane" is Amakusa dialect for crab, said to describe the shape of the fried strands, and the dish also serves as a vegetarian offering at Buddhist services.
- Tai SomenSomen noodles are simmered in the broth of sea bream head and bones cooked down whole — a celebratory dish said to reflect the influence of nearby Shimabara's somen tradition. In Yamato's Mamihara, a version called "taimen" simmers the whole fish instead.
- Tako MeshiSun-dried octopus is rehydrated, chopped, and either cooked into rice with burdock and carrot or mixed in afterward — a dish that leans on the concentrated flavor of dried octopus, known for the summer sight of octopus hung out to dry in Amakusa's Ariake.
- Baniku SobaFrom the Aso area of Kumamoto: hot soba topped with horse meat simmered sweet and salty. It's said to carry the history of a region where horse meat took root as a restorative food for the injured and ill.
- ButaaeBoiled octopus and eggplant are stir-fried in a sweet, spicy barley miso — an Amakusa home dish said to have begun as a stand-in for pork, once hard to come by, using the local octopus instead while keeping the old name, "pork mix."