Considerations on grape cultivation in Hida ①-2021
It's already been two years since I decided to make wine. Since starting to sell cider in July 2020, I've received inquiries from various places, so I thought it would be a good time to compile some thoughts on grape cultivation in Hida. Please read on only if you have time.
*This is strictly my personal view as of April 2021, with the understanding that my thoughts may change in the future. It is based on this philosophy that I am undertaking actual cultivation.
-History of Hida Wine-
I believe the recorded history of Hida wine began quite recently, in 1987, with the "Wild Grape Subcommittee" (later the "Hida Wild Grape Research Association"). (Some people argue that alcoholic beverages made from wild grapes or Labrusca-type grapes are not wine, but here, given that the history of Japanese wine was originally the history of table grapes, I will consider these as wine.)
However, at the individual farmer level, wine was being made around the same time that table grape cultivation began. In fact, in the 1970s, I heard that people were making wine for their own consumption using Muscat Bailey A and White Early (Seyve-Villard 9110).
Around 1970, a table grape growers' association was established, and at its peak, there were more than a dozen member farms in Kokufu Town alone. They absorbed techniques from advanced grape-growing regions and even possessed the skills to build flat trellises themselves. Just as the Hida grape industry seemed poised for further development, heavy snowfall struck Hida.
December 1980 - March 1981: Goro Gosetsu (Heavy Snowfall of Showa 56)
December 2005 - February 2006: Juhachi Gosetsu (Heavy Snowfall of Heisei 18) → Damage Report
Each time a flat trellis collapsed due to the snow, the number of grape growers decreased, and now only a few remain, including our vineyard. In recent years, due to global warming, the usual snowfall tends to decrease, but it is expected that snowfall will increase during heavy snow events.
-Factors Influencing Grape Flavor-
In grape cultivation, the most important aspect is canopy management (vine management). This refers to all cultivation techniques aimed at "controlling the microclimate through appropriate shoot positioning to obtain healthy and good quality fruit." Training systems are one of these canopy management techniques. However, even with the same canopy management, significant differences in flavor arise depending on the vineyard. Before delving into the discussion of trellis systems like vertical shoot positioning (VSP) or pergola, let's first consider what the fundamental factors are that determine grape flavor.
First, as a prerequisite, we will exclude conditions that hinder grape growth, such as being too hot, too much rain, constant shade, or overcropping. My conclusion after continuously tasting grapes at the winery where I trained during the 2020 season is as follows:
Climate (accumulated temperature, nighttime temperature) > Soil moisture content (precipitation, drainage) > Soil microbial activity (physical properties, improvement of trace element conditions) > Training system (VSP, pergola)
Regarding soil type, I believe that differences in physical and chemical properties affect both soil moisture content and soil microbial activity.
Furthermore, while rootstock type can cause shifts in flowering and harvest times, this is due to differences in vigor and the ability to absorb nutrients and water from the soil (or conversely, differences in sensitivity to the soil). Thus, similar to soil type, I believe it affects both soil moisture content and soil microbial activity.
First and foremost is climate. The growth stages of fruits can almost entirely be explained by accumulated temperature. Selecting grape varieties suitable for the local climate zone is crucial. Varieties like Pinot Noir and Chardonnay are early-ripening. By slowly cultivating such early-ripening varieties in cold regions, the aim is to accumulate aromatic precursors (substances that become aromatic after winemaking), ultimately producing high-quality wine. Hida's agricultural lands are distributed at elevations of 400m to 1000m, falling within climate zones I to III. These climates are suitable for planting premium wine grape varieties, and as long as the variety selection is appropriate, cultivation is possible almost anywhere.
Second is the moisture content in the soil. High moisture directly affects vine vigor and berry size. While table grapes demand large fruit, wine grapes, conversely, aim for smaller fruit. This is one of the qualities particularly desired in red wine. In red wine production, grape skins are macerated during the fermentation process, so the higher the proportion of skin, the more skin components can be extracted into the wine. Moreover, smaller berries prevent berries from touching each other, which not only helps prevent disease but also enhances concentration. Hida is a region with abundant rainfall. The precipitation during the growing season, from April to October, ranges from 1300mm to 1800mm, which is generally not considered ideal for grape cultivation. However, this heavy rainfall is concentrated until July, and if we can manage through this period, the autumn climate is not inferior to renowned wine regions. Rainfall that determines fruit quality has the most significant impact from one month before harvest. Therefore, if the weather after August is good, high-quality grapes can be harvested. (At least for table grapes, this has been proven.)
Third is the microbial activity in the soil. ~Since this involves electronic techniques, I will write about it after studying more~
Fourth is the training system. It is commonly said that VSP is typical for wine grape cultivation, but I don't agree. I have tasted grapes from various training systems, and if proper vine management and limiting the number of clusters per vine are maintained, there is almost no difference in taste due to the training method, at least when eaten fresh. (Whether my taste buds are faulty or not is beside the point.) I am aware of arguments that by uprighting shoots, fruit enlargement is suppressed, the proportion of skin in the fruit is increased, and concentration is achieved. However, my conclusion is that the influence of climate, soil moisture content, and soil microbial activity is greater than these factors. In fact, I observed concentrated grapes even in pergola-trained vineyards during my training, and some research papers investigating differences due to training systems found no difference in berry size. In other words, the discussion about training systems should only begin when one wants to produce even higher quality grapes in a location already capable of high-quality grape cultivation that meets the aforementioned three conditions. Outside of what are probably called renowned wine regions (places with optimal climate for the variety, excellent underground physical and chemical properties, and active soil microbes), I believe the honest truth is that there are improvements to be made before considering the training system, as long as the principles of canopy management are followed.
Based on the above, I will now consider grape cultivation methods in Hida.
