Updated: Mar 17
We've covered a quick overview on the major wine regions in Japan earlier in this article. Today, we will be doing a further deep-dive into the 'terroir' side of things.
Before we dive into details about Japan, we need to first understand what are the important elements that affect the wine we drink, as even the same grape varietal can produce vastly different wine depending on what type of soil and in what climate it’s grown. Some wines do best in cool, even cold, climates, while others are better-suited to warm, sunny weather.
So what's important?
Rainfall: the amount of rain needs to be just right, vines must have the water they need to ripen, but no more than that. With too much rain, the grape berries will start to swell, grapes will not produce enough sugars, acids or phenolic composites, while risk of spoilage, mold and mildew also increases. You will often hear the term 'diluted' when speaking about a vintage that has had too much rain. Although it is said that the ideal rainfall for vine growing is about 500～900㎜ on an annual basis, the timing for when rainfall is mostly concentrated in is also very crucial. It is better to have more rainfall before flower blossoms, and less after it blossoms, as ripening requires plenty of warmth and very little water.
Sunlight: sunlight plays an essential role in the ripening of a grape berry. It helps ripen grape skins and seeds. Usually the greater the number of hours of sunshine means the sweeter the grape, higher alcohol level, and a richer taste, while risk of vine diseases and pests also decreases. It is said that with sunshine, 1,300～1,500 hours is needed at the minimum for vine growing.
Temperature: it is often said that vines grow best in two relatively narrow bands, between latitudes 30 and 50 degrees in the northern and southern hemispheres. Why is that? It's mostly due to temperature. Most vines can only live in a certain temperature range and can only adapt so much to extremes in climate. It is said that the best temperature for vine-growing is at an annual average of 10～16℃. In early summer, the ideal temperature should be around 15～25℃, while during the ripening period, 20～25℃ is ideal during the night times. Also worth noting that a large change in temperature between day and night times is beneficial for ripening of grapes.
Soil: soil is another element that is crucial in a successful harvest of wine grapes and quality wine production. Soil not only influences the quality of the wine, it also affects the characteristics of wine grape through their supply of minerals and nutrients to grape vines. Some common soil types include sandy, clay, loam, volcanic, limestone, and silt soil. Sandy soil are well-drained and retain heat, they usually produce elegant wines with high aromatics, pale color and low tannin. Clay soil tends to stay cooler and also retain water, usually produces muscular wines with high extract and color. Loam soil are very fertile and typically causes vineyards to be over vigorous, thus they are often blended. Volcanic soil as the name suggests, are results from volcanic eruptions, they retain and reflect heat, drain well and holds water, rich in specific minerals like iron, calcium, magnesium, and potassium. Limestone soil are famous for quality winemaking, they are formed from the decomposed bodies of fish and other organic material which once lived in the ancient seabed, has good drainage in wet weather but retains water in dry weather. Silt soil retain water and heat, usually produce smooth and round wines with slightly less acidity.
Now that we understand the different elements that influence the wine we drink, let's look at where Japan sits with each of them.
Rainfall is probably the biggest challenge Japan has been combating against in the past few decades, given its location in the eastern side of Asia's Monsoon.
It Rains Twice As Much in Japan vs. Rest of the World!
Japan's Average Rainfall vs. Rest of the World (in mm/ year)
As you can see in the graph above, Japan's average rainfall per year is 1718mm, roughly twice of the word's average of 880mm. As shared earlier in the article, excess rainfall makes vineyards particularly susceptible to diseases and pests, among many other downsides including lower yields. One characteristic of Japan's rainfall however is that it is mostly concentrated in two periods of the year, the monsoon season (usually June - July) and the typhoon season (usually August - September). Take Tokyo as an example, there was as much as 208.5mm rainfall in September, but only 39.6mm in the month of December, as you can see, the gap between the 2 months can be as much as 5 times.
Ok, we know that Japan as a whole has a much heavier rainfall versus the rest of the world, but what about the major wine regions in Japan?
Terroir of Major Wine Regions in Japan
Rainfall by region
(Source: Prefectures Grading Research)
We have mentioned at the beginning of the article that the ideal rainfall for vine growing is about 500～900㎜ on an annual basis, but as you can see in the chart above, Nagano is the only prefecture to come close to this ideal range. In fact, Nagano is not just the prefecture with least amount of rainfall among the major regions, it is actually the prefecture with least amount of rainfall in all of Japan. The four major wine regions actually all rank within top 10 in terms of prefectures with least amount of rainfall. Nagano #1, Yamanashi #3, Hokkaido #4, Yamagata #10.
Sunlight by region
(Source: Prefectures Grading Research)
Next up we have sunlight. Yamanashi is at the top of the list, with average of 2,335 hours of sunlight per year, it is the number 3 prefecture in Japan in terms of prefecture with the most sunlight. You will notice all major wine regions far surpass the 1,300～1,500 hours minimum sunlight needed for vine growing. Again more sun means less vine diseases, less pests, and sweeter wine.
Temperature by region
(Source: Prefectures Grading Research)
When it comes to temperature, it is not surprising to see Hokkaido ranking in number one as the coldest region in Japan. It is interesting however, that all of the major wine regions in Japan rank within Top 15 as the coldest regions in Japan. Hokkaido #1, Yamagata #4, Nagano #5, Yamanashi #14. This again is likely due to vine's inability to withstand the brutal hot summers in many parts of Japan.
Before we move into further details about the characteristics of the different wine regions, the top grape varieties grown there etc., we need to first understand the effects 'climate' has on the grape varietals most suitable to be grown in that region, essentially most can be categorized under 'cool climate' vs. 'warm climate'.
“Cool climate” regions usually produce grape varieties like Chardonnay, Pinot Noir, and Sauvignon Blanc, while varieties like Cabernet Sauvignon are usually much harder to be grown in this colder climate. Cool climate vines tend to produce less fruit per vine, i.e. less yields. The winemakers also need to ensure the wines are not too sour, are balanced with enough sweetness, as grapes grown under cool climates do not ripen as quickly, have less natural sugar, and higher natural acidity. The wines are often described as being more subtle or refined.
"Warm climate" regions on the other hand tend to have more consistent temperatures throughout the season, which gives grape berries ample time to fully ripe. Opposite to winemakers in cool climate, winemakers in warm climate need to ensure their wine have enough acidity, given the fully-ripe grapes usually have higher natural sugars, and therefore higher alcohol levels. Warm climate wines often have a flavor that's more rich and full. Grape berries in warm climate also tend to have thicker skins to protect themselves from the heat, and this results in more tannic wines. Which is why the art of winemaking becomes crucial to avoid certain factors dominating over others, particularly with wine made from warm climate.
Now that we understand how climate affects the grape varieties most suitable to be grown in that region, let's dive into actual details about Yamanashi, Nagano, Hokkaido, and Yamagata.
Yamanashi, the birthplace of Japanese Wine, home to Mount Fuji, and is located just 1.5 hours train ride away from Japan's capital, Tokyo. It is the prefecture with the most number of winers, and it also the largest in terms of wine production in Japan.
With Mount Fuji to the south, Minami Alps (Akaishi Mountains) to the west, Yatsugatake to the north, and Okuchichibu Mountains to the east, Yamanashi is an inland prefecture surrounded by mountains over 2000-3000m above sea level. This makes Yamanashi an ideal location to grow vines given the less likelihood to be affected by monsoon (rainy) seasons, typhoons, while enjoying less rainfall and long hours of sunlight throughout the year.
Most of the grapes grown in Yamanashi are cultivated in the Kofu Basin. With the inland climate that's unique to the basin, the large temperature difference between summer and winter and day and night, the less wind given the surrounding mountains, this area is very suitable for cultivating high-quality grapes. In the eastern part of the basin, you have Katsunuma Town, Koshu City, and Fuefuki City which are areas that have had long history in wine production. While in recent years, more and more new vineyards are seen established in the northwestern part of the basin and near Mount Yatsugatake.
In terms of soil conditions, it is mostly clay soil mixed with gravel in Yamanashi. So although it is not ideal for growing rice, it is very suitable for growing grape vines.
Now let's look at what the top grape varieties are that's grown in Yamanashi.
Top White Grape Varieties Grown in Yamanashi
Top Red Grape Varieties Grown in Yamanashi
(source: National Tax Agency, conducted in 2018)
You will realize that wine produced in Yamanashi is absolutely dominated by the 2 indigenous grape varieties of Japan, Koshu for white, and Muscat Bailey A for red. But why is that?
Well, it's mostly because of both historical and terroir-related reasons.
Did you know that the first bottle of Japanese Wine was actually made from Koshu grapes in Koshu? Wait what? Is that a typo? No, in fact, 'Koshu' was the ancient name for 'Yamanashi Prefecture' that we know today, in fact, that's where the the grape variety 'Koshu' got its name from! Another fun fact, Koshu is said to be the only grape variety grown in Japan up until the Edo period (~1600). Also, it used be grown for eating, wasn't until much later that people realized its potential and charm to be used as grapes for winemaking.
The second reason is because of terroir. Yamanashi, as mentioned earlier in the article, is one of the top prefectures in Japan with the most annual sunlight. Extended sunny days, paired with high altitude and great drainage in Yamanashi, provides excellent environment for Koshu vines to strive. In addition, Koshu's thick skins also make them comparatively resistant to vine diseases.
Muscat Bailey A on the other hand, also shares similar characteristics as Koshu in the sense that both have thick skins, making them resistant to fungal diseases. Muscat Bailey A was developed by Kawakami Zenbei, the "grandfather" of Japanese wine, in 1920s with the aim to create a red grape variety that is suitable for the humid and freezing cold climate of Japan. The early and easy ripening characteristics of Muscat Bailey A make it a popular variety widely grown in not just Yamanashi, but also in prefectures like Yamagata.
Next up we have 'Nagano'. Nagano, similar to Yamanashi, is surrounded by 3,000 meter high mountains, the Japanese Alps. First characteristic that makes Nagano a great region for wine production is the amount of rainfall it gets. Nagano is the prefecture in Japan that has the least amount of rainfall. Averaging about 902mm per year. Again, having too much water is not good for the ripening of the grape berries. Next crucial element of quality wine production is the amount of sunlight the vines get, which Nagano again far surpasses the ideal vine-growing minimum of 1,300～1,500 hours, averaging at 2,028 hours per year. Third characteristic is its broad day-and-night temperature swings, given its inland climate, which is beneficial for ripening and the retention of natural acidity. With temperature dropping during night times, the sugar content increases and it also helps with grape coloration. Lastly, Nagano enjoys great drainage. Although Nagano is the prefecture in Japan that has the least amount of rainfall, it still has relatively high rainfall when compared to the major wine regions in Europe. To cope with this, slopes that's seen everywhere in Nagano's Shinshu Wine Valley helps with draining even if it rains. Meanwhile, rocky, volcanic soils with cool summer breezes also help maintain the health of the vineyards in Nagano.
The high altitude of vineyards in Nagano usually means delayed ripening, so the fruit is picked later during autumn when it is cooler. Longer and slower ripening results in increased flavor intensity, tannin structure, and balance. Lastly, worth noting that the wine industry in Nagano Prefecture is highly supported by the local bodies, with Nagano Appellation Control (NAC) established in 2002 to improve the quality of Nagano Wines. Wine areas in Nagano are branded as the Shinshu Wine Valleys, which consists of Kikyogahara, Chikumagawa, Nihon Alps and Tenryugawa Wine Valley.
Top White Grape Varieties Grown in Nagano
Top Red Grape Varieties Grown in Nagano
(source: National Tax Agency, conducted in 2018)
As we can see in the charts above, the top varieties for both red and white wine grown in Nagano are American varieties, Concord and Niagara, which account for roughly half of Nagano's wine production. But why?
In short, because they are the easiest to grow. Both Niagara and Concord are known for their tolerance for extremely cold weather conditions and their resistance to vine diseases. This is particularly important as Japan has had multiple times of failur