Kojima Sohonten: A Leading Yamagata Brewery Goes Carbon Neutral
Kenichiro Kojima, Kojima Sohonten’s 24th-generation president. All photos courtesy of Kojima Sohonten.
The traditional front of Kojima Sohonten belies the ferment of sustainable innovation going on within.
I’m always interested in what sake breweries are doing to shrink their carbon footprints and brew in a more sustainable way. During an interview to research this Plate Magazine article on three innovative sake breweries that are taking sake into the future, I spoke with Kenichiro Kojima, the president and 24th-generation head of Kojima Sohonten in Yamagata Prefecture. In passing, he mentioned that as of September 2023 his brewery had become carbon neutral.
The impetus to go green is not hard to understand. Japan is feeling the effects of climate change in the form of extreme weather events: unbearably hot summers have led to poor rice harvests, which can compromise sake quality or make it more challenging to meet normal standards. Meanwhile, the global embrace of ESG (Environmental, Social and Governance) sustainable development initiatives has spurred forward-thinking presidents like Kojima to look more carefully at how they can make their kura more climate resilient.
Kojima’s products (you might be most familiar with the brewery’s Toko line) are now sold in 20 countries and exports account for approximately 20 percent of the company’s annual revenue. This figure will grow as long as domestic consumption remains low and international interest in sake continues to rise steadily.
But as less-expensive internationally brewed sakes become more widely available, Japanese brewers are thinking hard about what international customers will want in a Japanese-made sake. How can they innovate while maintaining their made-in-Japan cachet? Techniques we’ve seen so far include returning to fermenting and aging sake in old-fashioned cedar barrels or, as Kojima has started to do, fermenting sake in 200-liter earthenware pots, or amphorae-like kame. For this, you can check out the brewery’s Toko Azuchi Momoyama, made with heirloom Kame-no-o rice polished to 50 percent (although returning to 90 percent in the near future), and named after the era of the brewery’s founding.
Sustainability is another attribute consumers are increasingly looking for in all products. In 2020, the 427-year-old brewery switched to junmai-only sake production. While many breweries have done this, I thought of it mostly as a way to cater to the increasingly dismissive attitude many foreign sake fans unfairly harbor toward honjozo, or aruten styles. In some cases, it is to comply with newly adopted Geographical Indications that specify that a sake be made with 100% local ingredients. But eliminating honjozo—which in 2009 accounted for 60 percent of the brewery’s production—was perhaps less about geographical purity and more about reducing the carbon footprint of its sake. In Japan, brewer’s alcohol, made by distilling sugar cane-derived molasses, is typically imported from Brazil or southeast Asia.
Modern sake brewing requires large expenditures of electricity to keep fermenting mashes at a constant low temperature, and increasingly, for end-to-end supply chain cold storage, especially for popular nama, or unpasteurized varieties. Shifting to completely renewable energy, last year Kojima Sohonten transitioned to biogas made from the lees of its distilled, shochu-based Toko ginjo ume (green plum) liqueur, which itself is made using upcycled sake lees from the brewery.
To preserve local water quality, Kojima Sohonten in 2019 began purifying wastewater from the rice washing process via a pH-balancing aeration tank so that it can be safely discharged into a nearby urban waterway. So much impressive circularity!
Since heavy agrochemical pesticide and fertilizer applications can lead to nitrogen run-off that pollutes rivers, streams, and the wildlife that lives in or near them, Kojima Sohonten has been experimenting with organic rice cultivation since 2022, including the use of robots in the fields to help manage the weeds that are no longer being killed by chemical applications. Called the “Aigamo robot” after the tradition of using ducks in the fields for pest control, the Aigamo oxygenate the water as they cruise through the paddies like cute white Roomba, eating insects and weeds.
On the rice variety front, Kojima Sohonten has been working with local contract farmers to experiment with climate-adapted regional varieties to increase biodiversity and climate resiliency. Kojima says the local hybrid Dewasansan makes up most of the sake rice grown by local farmers, and among table rice varieties, a breed called Haenuki.
Kojima Sohonten , like many breweries, has found various ways to upcycle its sake-making byproducts for other commercial uses; it sells its rice bran—a byproduct of the rice-polishing process—to a business that extracts bran oil from it, and directs the remainder toward use in cosmetics or as fertilizer gifted to Kojima’s contract farmers.
This snapshot of an all-out sustainability effort by a brewery I admire is highly impressive, one of a number examples of increasing sustainability in the sake industry. I hope the trend continues and accelerates!