According to historical documents, the Iwase brewery was founded in 1723 and succeeded by the Iwase family head from generation to generation. Since the Taisho Era, the brewery has strived for serious sake brewing in full force, and in 1947 won the prestigious award as top-ranked sake in the Annual Japan Sake Awards. The current head, Yoshikazu Iwase is the 11th generation. His predecessor, Yoshiyuki (deceased) was also well-known as a photographer whose work focused on photos of female pearl divers since before World War II. He won the Prime Minister’s Prize at a Mainichi Newspapers-sponsored exhibition; his masterpiece is the photo collection
“Ama no Gunzo (Group of female pearl divers)”.

The ancient wooden beams of the sake brewery’s thatched roof purlin are made from the masts of the “San Francisco”, a 16th century galleon which collided with reefs off the coast of Onjuku in 1609, leaving its crews stranded on the beach. Its 373 passengers, led by Philippine ex-Governor Don Rodrigo, were on the way from Philippines to New
Spain (Spanish Mexico). Although 56 people among them passed away, the remaining 317 people were rescued by the villagers of present-day Onjuku. It was said that, at the time, the villagers emotionally sympathized with the castaways and the female divers warmed the frozen survivors with their bare skin to revive them, as well as generously provided their husbands’ kimonos and foods, which became a trigger for establishing
the friendship between Japan and Mexico/Spain. The incident was 400 years ago, during the era of the well known Shogun, Tokugawa Ieyasu.

The Sake Brewing Commitment (Yamahai and Koshu)

Onjuku Beach, also coined “Tsuki no Sabaku (The Moonlit Desert)” is located around 10 minutes’ walk from the brewery. The mother water for the brewery’s sake is the hardest in Japan at 13-15 on the scale, due to its extreme proximity to the Pacific coast and the passing of groundwater through layers of shells and minerals. The high calcium and magnesium content contributes to a rich, nutritious fermentation.

The application of the Yamahai method with this high hardness mother water further produces delicious, rich and high acid sake. The Yamahai method maximizes the flavors of the rice, and is a typical feature in the brewery’s offerings, with more than two thirds of the brewery’s sake now produced this way. With exception of Daiginjo sakes, Iwase have specially selected local Chiba Prefecture grown rice for all sake making.

After the initial sake-making process is completed in early spring they are almost always rested. This is the sake-making. The resting reduces the roughness and newness through the summer season, becoming mild by autumn. After one, three, five, ten, twenty or even thirty plus years of long-term storage, the sake becomes “Jukusei Koshu (Aged Sake)”. Even the Namazake can age for many years refrigerated.

Iwase Shuzo has brewed Ginjo style sake since 1930 and has won numerous awards. At the time, the participating sake in appraisals and competitions were brewed for the purpose of improving techniques, and were not sold, as they are today. Batches of those sake remain slumbering in the brewery warehouse, even still! Tasting some batches after ten years in storage, the sakes had developed into different colors and a comfortable fragrance had intertwined with such mellowness and richness that it was clear they had aged into wonderful sake. After that, Iwase slowly began storing more sake, later leading to the comprehensive storage of our annual batches since the 1960s. These form the “Iwanoi” series of well-aged sake, certain to enrich your heart.