2020-09-25 The weather and producers

The weather and producers

Is the weather giving hard time for producers all the time? This year in Hong Kong, the weather seems to be quite strange like lots of sudden rains in summer. Those funny weather can be seen in other areas such as serious wildfire caused by lightning damage in California as well as heavily hailstorm at Valpolicella, Veneto region in Italy. It assumingly might be influenced by global warming and it seemed as if the god showed his anger… It is a pity that grapes from those regions are really damaged. The condition of grapes is quite reflected by weather & climate, so that the grape growers always check both weather and grape condition time to time and they cannot be relieved until their grapes are harvested safely without any problems.  

It is fundamental to have good condition of grapes.

 “You can produce good wine from good grapes, but you cannot produce good wine from bad grapes.” In other word, the quality of grapes determines the quality of wine…. Well, I agree with its opinion partially. The condition of grapes is very important for making good wine, which is really true, but it is not all. If winemakers has good condition of grapes, it is easier to handle winemaking indeed, therefore I convince that grape growers make a maximum effort to grow grapes at good condition.

What is it for grapes at good condition?

 It is required for the growth of grape to receive appropriate amounts of sunlight, temperature and water for sure. In order to obtain healthy grapes without any damages, it is very important for grape growers to judge how to manage their vineyard.  I highlight here “appropriate amounts”, which is actually very tricky word. What do you think how much appropriate amounts for grapevines is? It depends for grape variety and its environment including climate, weather, water and soil condition etc… For example, there is high humid condition due to long rainy season(梅雨) and several typhoons in Japan, conversely there is serious drought problem in South Australia in terms of water issue.

Excess water is problem or not?

Excess water can be problem before harvest, although it is not bad for grapevine to have sufficient amount of water during growing season, prolonged rainfall tends to promote fungal diseases. Those diseases attack grapevines and grapes, subsequently they are molded. Spraying is applied to grapevine and grapes in order to prevent from fungal disease in many regions in general. The water or rainfall itself is “not really big” problem, but subsequent issue caused by fungal disease is most concerned in humid regions such as Hunter Valley in Australia and Bordeaux etc… But there is long rainy season in Japan except Hokkaido, thus some producers apply extra care for protection about excess water.

Picture 1: Overhead protected canopy
Source: Suntory Tomi no Oka Winery

Special rain protection

They set up special canopy of transparent polyethylene vinyl sheet to cover on the top of grapevine in order to protect from rainfall directly. (Picture 1) It can be rolled up or removed whenever it is sunny condition to receive direct sunlight. Unfortunately, all rain cannot fall vertically, sometimes diagonally caused by stormy rain, therefore this system is not 100% perfect protection although approximately 80% of raining situation can work well. In addition, humidity among grapevines can be released by removing or rolling up this sheet as well. This special protected method, called as “Rain-cut (Rain protection)” in Japan, is really unique system, which you only see it in Japan. As you assumed, it definitely costs a lot, so it is not common to install it for all grape growers/ wineries. 

Picture 2: Mini-size protected canopy over the bunches:
Source: Suntory Tomi no Oka Winery

There are many typhoons hitting to Japan this year, it was extremely hard for grape growers / wineries especially mainland island (本州). The harvest of grapes had been started since the end of August (it depends on regions) and winemakers are taken over the role to handle grapes for making wines no matter how good or bad the quality of grapes is.  They will check the condition of grapes and carefully choose optimum techniques to apply for grape handling in order to produce wines as best as possible. Is the weather giving hard time for producers all the time? Although it is not all the time, the frequency of challenging phase seems to be more often. The weather is unable to be controlled, thus the growers themselves have to adapt each weather condition for grapevines. Eventually, it affects winemakers’ activities or choice indirectly. I wish producers included both grape growers and winemakers to have less challenging situation.


• U.S.News, 30, Aug, 2020. “Wildfires Again Threaten Business in California Wine Country” https://www.usnews.com/news/business/articles/2020-08-30/wildfires-again-threaten-business-in-california-wine-country.
• Decanter, 3, September, 2020. “Violent hailstorms hit Valpolicella vineyards”
• EEna! Countryブドウ雨除けhttps://eenacountry.com/fence/
• Suntory Tomi no Oka Winery https://www.suntory.co.jp/wine/nihon/wine-cellar/tominooka.html