Yamanashi Wine with an IT Twist

A Tokyo couple in their seventies are visiting the Okunota Winery in the city of Kōshū, Yamanashi, to sample its wares. “Oh, this has a wonderful aroma. It would make a nice aperitif too,” they remark. After trying out several samples, they buy eight bottles of wine, two each of four different varieties. They’ll be stocking their wine cellar, “keeping one bottle of each to age, in order to enjoy the taste difference later,” they say.

Early October is grape harvest time in the Enzan and Katsunuma areas, east of the Kōfu valley. This is where Japan’s first wines were produced in the late nineteenth century. Today the Okunota Winery is at the cutting edge, using information technology to manage grape-growing using sensors and wireless networks. These tech advances have brought the side benefit of dramatically reduced pesticide use.

Combining Old Farming Methods with New Tech

Okunota winery President Nakamura Masakazu explains that he began using IT simply because he wanted to improve the quality of his wine; going pesticide-free was not his primary goal.

While studying microbiology at the Tokyo University of Agriculture, Nakamura became convinced that improving the microbiological environment of the fields could help produce quality wine. Since launching his grape-growing operations in 1998, he has concentrated on preserving the soil’s microbiological environment so that minerals can be absorbed deep in the soil. He plants vines close together, forcing their roots to grow deep, and uses a no-fertilizer, no-till growing method that leaves weed roots in place to enrich the environment further.

The chance to bring tech into the mix came along in 2010, when Nakamura lent part of his farm to employees of the electronics giant Fujitsu as part of its employee farming support activities. The company suggested placing networked weather sensors in his fields. This system automatically collected and stored data on temperature, humidity, sunlight, and other environmental information at 10-minute intervals. That gave Nakamura the idea to put this data to use in monitoring what was happening in his fields.

Analysis began after installation of the sensor network in 2011. As a result, Nakamura learned some important facts about his farm.

Just One Aim: Producing the Best Wine

“Fungicides are needed to stop disease-causing mold from developing, and the traditional thinking is that they must be applied regularly to the fields,” explains Nakamura. “But when we analyzed the data, it showed that there were only about four days a year—or perhaps eight in a really bad year—when mold outbreaks were a real concern.” When warm, humid conditions continue, mold sends out bacterial threads all at once. Fungicides don’t work on mold at the spore stage. “It’s at the germination stage that mold is most vulnerable, and even highly diluted pesticide will work effectively then, so I don’t even need to wear any protective gear when spraying.”

A system is now in place that collects weather data via the wireless network and forecasts when the fields need to be sprayed. The outcome is that fungicide use can be kept to a minimum.

An environment rich in microorganisms promotes the growth of wild yeast and has a positive effect on the wine fermentation process. Adds Nakamura: “Wine in which wild yeast has been carefully nurtured has a generous flavor profile. Everything we do here is to create an environment for microorganisms to make good-tasting wine.”

Wine and Its Terroir

Since wine is alcohol made exclusively from the juice of grapes, 80% of the taste depends on the quality of the fruit. This makes it vital to grow in fields that provide ideal conditions for the fruit’s development.

For example, Romanée-Conti, one of France’s most prestigious labels, uses grapes grown in Burgundy in premium fields (grand crus) covering only 1.8 hectares. The hilly terrain creates microclimates and differences in soil quality from field to field, which affect the growth and ripening of the grapes, so the fields are ranked in painstaking detail. “Terroir” is used in the wine world to describe the comprehensive natural environment, including everything from climate to soil, that affects the grapes’ growth, causing the wines produced in a particular spot to embody those qualities.

Japan is also making great strides in producing wines with distinct local characteristics. Today a growing number of Japanese producers, starting from scratch with grape-growing and working hard to produce quality wines, have been winning international awards for their creations.

Labeling rules were changed in 2018 so that only wines made from domestically grown grapes can be called “Japanese wine.” There are already wines on the market labeled as containing 100% Yamanashi grapes, too. Japan currently has over 250 wineries, from Hokkaidō to Kyūshū, and as the amount of land given over to growing grapes for wine has expanded, research is picking up steam into the ideal varieties of grape for land at specific elevations, temperatures, and soil qualities.