Around June 1 — World Milk Day — craft sweets brand Butter no Itoko is drawing attention to the untapped value of milk. Founded in Nasu, Tochigi Prefecture, the brand was built around a striking fact: when dairy farmers make butter, only around 4% of raw milk is converted into butter, while over 90% remains as skim milk (defatted milk), a byproduct that has long been difficult to monetize at its true value.
Changing Conditions for Japan's Dairy Industry
Japan's dairy sector has faced a shifting landscape in recent years. Factors including population decline, a shrinking school lunch demographic, growing beverage diversity, rising costs, and changing dietary habits have transformed how milk is consumed. Despite falling demand for drinking milk, raw milk production continues daily — it cannot simply be stopped — meaning surplus supply has become an ongoing challenge.
According to official statistics from Japan's Ministry of Agriculture, Forestry and Fisheries, since the Reiwa era began, raw milk supply has consistently trended above demand. While production volumes have risen, consumption of drinking milk has declined and commercial demand has shifted, making supply-demand balance a persistent issue for the industry.
When demand decreases but production cannot easily be cut, surplus milk is processed into longer-lasting products. Butter is one of the most common outlets — but every batch of butter generates skim milk as a byproduct. As butter demand rises, so too does the volume of skim milk produced, creating a growing need to find meaningful uses for it.
The Origins of Butter no Itoko
Butter no Itoko ("Butter's Cousin") was born from the dairy-rich region of Nasu, Tochigi Prefecture. The brand set out to highlight the overlooked potential of skim milk — a nutritious and flavorful ingredient that, despite being a byproduct of butter production, had long been traded at low prices or left without a clear purpose.
By developing a craft sweet centered on skim milk, Butter no Itoko aims to give that ingredient genuine value, while also creating local employment and contributing to regional revitalization.
A Distinctive Three-Part Texture
The signature product is a gauffrette (wafer sandwich) filled with milk jam made from skim milk, delivering what the brand describes as a three-part texture: "fluffy, crispy, and creamy." A soft butter-rich wafer sandwiches a layer of crunchy butter cream and a rich, flowing milk jam, creating a balanced bite that puts skim milk in the spotlight.
Handcrafted for a Reason
Rather than scaling through full automation, Butter no Itoko has prioritized handcraft production. Even as the brand has expanded to stores across Japan, its in-house factory continues to make each piece with a hands-on approach. The brand's concept — "creating a new cycle through eating" — reflects a commitment to using every part of an ingredient while connecting producers, local communities, and consumers.
The brand also emphasizes inclusive employment, with the production process designed to bring in workers from various backgrounds as part of its broader community-building mission.
Skim Milk Rescue: Over 64 Tonnes Used
Between April 2025 and March 2026, Butter no Itoko used approximately 63,823 kg of skim milk — the brand refers to this effort as "skim milk rescue." Rather than treating skim milk as leftover material, the brand positions it as a "material connected to the future," building its production around the idea that fully utilizing an ingredient is itself a contribution to the dairy industry's sustainability.
Flavors Across Japan
Butter no Itoko offers five standard flavors — Milk, Chocolate, Anko Butter (red bean butter), Uji Kintoki (matcha and red bean), and Salted Caramel — alongside seasonal and regional limited editions available at select locations across the country.
Regional exclusives include Strawberry Chocolate (Tokyo), Uji Matcha (Kyoto), Choco Banana (Osaka), Banana (Nasu), Choco Caramel (Haneda Airport), and Hiruzen Rich Butter Milk (Hankyu Umeda Honten). Location-exclusive gift boxes are also available at Tokyo Station, in Hokkaido, Osaka, Nasu Kogen, Kyoto, and Haneda Airport.
The standard three-piece box is priced at ¥1,080 (tax included), with THE GOLDEN BOX (4 flavors, 3 pieces each) at ¥4,158 and the regional gift box at ¥6,210.
On World Milk Day and beyond, Butter no Itoko continues to present a model for how Japan's dairy sector might find new paths forward — not just through what people drink, but through what they eat and bring home as a souvenir.
