Terroir (ter-war) is used to define the characteristics of a place (soil, water, altitude, latitude and climate) that effect the taste of a final agricultural product. Wine is the main agricultural product defined by terroir. The French really drove the use of terroir in describing agricultural products with its regulations requiring use of region in labeling of French wine. For example, wines produced in the Bordeaux region of France are classified by a sub region in relation to where they are to the Garonne River – Saint-Estèphe, Paulliac, Saint-Julien, Margaux, Graves, Saint-Émilion and Pomerol. These classifications were originally made in 1855 and have been adhered to since then because they have helped the producers to distinguish their products from each other, define quality and drive up prices. Tea can also be defined by terroir; the only problem is that the producers of tea are not always using this to their advantage. India is one exception – Assam, Darjeeling, Kangra, Dooars, Terai and Nilgiri teas are all named after the region in which they are grown and marketed in a fashion that helps the consumer associate the region to the flavor of the final beverage.
So what conditions does tea need to grow? To its advantage, the tea plant is a very versatile perennial, so it can grow in a variety of soil types.
However, for optimal production the soil should be acidic, between 4.5 to 5.5 ph., loose enough to allow the 6 foot tap root to burro down to its preferred length, and contain a good mix of nutrients (Nitrogen, Magnesium, Calcium, etc.) that the tea plant uses to grow. Like other plants, it will strip nutrients from the soil necessitating replenishment via some manner of fertilization. The Japanese use grasses to re-fertilize their tea plants, which influence the taste of the final tea and is credited by the tea farmers for the complex flavors of their teas.
Five hours of direct sunlight is optimal, however, less light disturbs the chloroplasts in the tea leaves, creating more aromatic oils and slowing growth. This is why high altitude teas are considered the higher quality tea, they get between 2-3 hours of sunlight, creating more aromatic oils. Those oils create the complex flavor of those teas. More than five hours and plant will continue to grow, but the flavor will be dramatically different.
The tea plant likes lots of water, but doesn’t want to sit in it. Plants need at least 50 inches of rain annually and 70-90% humidity. By definition the water and humidity requirement put the plant in the sub-tropic to tropic zone, and while it can handle some weather variation it cannot survive prolonged dry seasons or freezing.
Latitude effects terroir through the length of the growing period. The closer to the equator (think Kenya and Argentina), the longer the growing period. In Kenya, tea is harvested year-round while it is only harvested twice a year (spring and fall) in most Chinese regions. Tea in Taiwan is harvested five times a year between April and December with the July and August harvests continually ranked as the finest.
So how does one use terroir when purchasing tea? Look for where the tea comes from, and if possible search for single origin teas from one tea plantation. This will allow you to identify the flavor unique to the tea produced in that region, for instance Assam tea is consistently malty in flavor. Dongding Oolong produced in the Nantou county of Taiwan is said to gets its unique award winning flavor from the constant fog in this mountainous region. There are many black teas from China associated with the provenience it is grown it. A Yunnan black tea tastes very different from a Fujian black tea. So treat your teas like wine, know where they come from, learn their flavors and enjoy comparing them. It makes drinking a cup of tea a truly special experience.
What do you think? Can you taste the terrior in your tea?