
Bright blue mochi rice cakes made with powdered butterfly pea flowers
November 2, 2021
OTSU — Taiyaki fish-shaped grilled pastry filled with bean paste, somen noodles, mochi rice cakes and more are coming down with a case of the blues around Lake Biwa in Shiga Prefecture.
Food products made with natural blue coloring are being produced in the prefecture one after another and are proving more popular than expected, especially among young people keen for their next social media-worthy moment.
Moves are afoot to trademark the name “Biwako Blue” (Lake Biwa blue) and make bright blue food a nationwide craze.
At a food truck set up in front of the Shiga prefectural government office, blue mochi rice cakes were seen selling like mad. The customers were mainly young people, and many immediately took pictures and posted them on social media. The 200 pieces prepared for the day were sold out in about an hour.

Taiyaki fish-shaped pastries filled with blue bean paste are seen.
“Our blue mochi rice cakes sell out quickly, both at the truck and food events,” said Sadao Kawai, the representative of Koka Mochi Kobo, a rice processing and sales company in Koka, Shiga Prefecture. “I was determined to break through the sales slump caused by the COVID-19 pandemic, but this has exceeded my expectations.”
The blue rice cakes are among about 40 products created under the Biwako Blue Project, which started in March.
Nihon Advanced Agri Co., a food and beverage company in Nagahama in the prefecture, developed a natural blue coloring agent and has called for the development of more blue products. About 30 local companies and the Association of Bio Business Creation have joined the project.

Pudding with blue jelly
The raw material for the coloring agent is the butterfly pea, a legume that grows wild in Southeast Asia, including Laos and Thailand. The pea’s blue-violet petals are rich in anthocyanins, giving the plant its vivid blue color, and are used locally for dyes and herbal teas.
Nihon Advanced Agri learned of the potential for the butterfly pea when it expanded its business into Laos in 2014. An initial hurdle was that it turned gray when processed for food production, but the company succeeded in developing a vivid blue colorant in powder form using a special sterilization technology after a three-year effort.
In September 2019, the Health, Labor, and Welfare Ministry granted the use of the coloring as an additive in food products.

The bright blue flowers of the butterfly pea
The first commercialized product — blue chocolate — was a hit, selling about 30,000 boxes. The company then called on other food producers to use the coloring to boost Shiga Prefecture’s sluggish economy, dragged down by the COVID-19 crisis.
Many people expressed amusement on social media, with posts such as, “Apparently, there is a lot of blue food in Shiga.”
Nihon Advanced Agri is applying to trademark the name “Biwako Blue” and logo to make it as common as the green of matcha green tea.
Related products can be seen on the project’s website (https://biwakoblue.org/).
"Features" POPULAR ARTICLE
-
Neko Pitcher
-
2025 Expo Osaka : Visitors Enjoy Opportunity to Drink Alcoholic Beverages from Around the World
-
Giant Butterbur Harvest Peaks in Hokkaido;Edible Plant Grows Taller Than an Adult
-
Kagoshima: Sandbar Allows Visitors to ‘Walk Across Sea’ Like Moses
-
‘Rice Meister’ Shares Tips on How to Cook Tasty Stockpiled Rice; Soaking, Adding Sake Among Tricks to Restore Old Rice
JN ACCESS RANKING
-
Japanese Researchers Develop ‘Transparent Paper’ as Alternative to Plastics; New Material Is Biodegradable, Can Be Produced with Low Carbon Emissions
-
Japan’s Cooperation in Alaska LNG Development Project Emerges in Japan-U.S. Tariff Negotiations; But Industry Concerns Exist
-
Average Retail Rice Price Up for Second Consecutive Week; More Than Double Same Period Last Year
-
Trump: Nippon Steel Will Part Own U.S. Steel, U.S. to Be in Control; Share Distribution, Other Details Remain Unclear
-
Japan’s Maglev Shinkansen’s Partially Completed Station Unveiled; Station Will Be Only Underground Stop Between Shinagawa, Nagoya