Terroir

The major ingredient of sake, rice, differs from region to region, but breweries tended to use both local rice and rice from other regions, the difference between various regions’ rice varieties has not been given much thought. Recently, however, the sake industry has been increasingly favoring local rice and therefore creating regional differences in sake. This requires an increased interest in the way that growing conditions affect the rice and, therefore, the regional expression of each sake.

In the wine industry, cultivation methods and selection of grape varieties have long been chosen based on local climate and growing conditions, known as terroir. Terroir of an area is derived from four components.

#1. Temperature

Grapes mature earlier when the temperature is higher. Temperature differs from region to region so the Huglin Index (HI, a calculation taking into account 1 April – 30 September average temperatures, maximum daily temperatures and length of day according to latitude) is useful when considering the cultivation of grapevines.For instance, in Champagne, the Huglin Index is 1550, in Bordeaux it is 2100 and Fresno (California) it is 3170. Each grape variety grows better in areas with a certain HI, so traditional wine regions such as France have taken a long time to determine the best grape variety for each growing area.

#2. Water

Water significantly affects plant vigor and when vines feel water stress (insufficient water), they stop growing shoots and leaves and instead send nutrition to the grapes. However, if heavy water stress is experienced during the early growing period, shooting stops and vines have insufficient leaves for photosynthesis.Water stress in terms of terroir is a factor of precipitation and water retention in the soil. Clay and chalky soils have higher levels of water retention than gravel and sandy soil. For good growth, controlling water stress according to the climate and soil is essential.

#3. Sun exposure

It is important to have a balance between the leaf surface area and fruit volume. The best ratio is generally thought to be 1.5m²/kg. To achieve this ratio, growers consider where vine trees are planted and think about the orientation of vineyards to sun. In addition, they control leaf and shoot growth and crop yield.

#4. Nitrogen source

Nitrogen is a known factor to influence the flavor of grapes and wine. The typical aroma of Sauvignon Blanc is derived from thiol, which is produced more if soil contains nitrogen source. The typical aroma of Cabernet sauvignon is derived from IBMP and it increases when the soil has more nitrogen. When the amount of nitrogen source is controlled, the of aroma component is also controlled.