From Tencha to Matcha

If you are new to matcha or new to us, you may not have heard of tencha. Tea farmers grow tencha, which is then milled into matcha. In this blog post we are going to go into significant detail about how tencha is grown, and how it is then processed into matcha. 

Shading
Tencha is grown in the shade for the last 3-4 weeks before harvest. Like with many other areas of Japanese tea growing there are no regulations defining exactly how the tea is to be shaded, or exactly how long for. The majority of tencha is directly shaded by laying kanreisha (synthetic black netting) on top of the tea - usually a two person job with one person either side of the tea plants. As the netting is in direct contact with the leaves, some damage can occur due to rubbing, and it may be a less breathable and more humid environment for the tea compared to non-direct shading. Some tencha is shaded with wara (rice straw), which is weaved by hand and must be replaced every few years, making it much more expensive than kanreisha. Wara is said to introduce a specific smell to the plant (especially after raining) known as ooika - which translates to ‘shading smell’. 

While kanreisha can be used for both direct and non direct shading, wara is only used for non direct shading. This is when a tana (a frame or scaffold) is used to hold the shading material above the tea so there is no direct contact. This also allows the shading material to hang down around all sides of the tea, and the material can be adjusted to control exactly how much light is blocked. During the shading period, fertilising the tea is extremely important and not only serves to keep the tea plants alive during such a stressful time, but also influences the final flavour of the tea.

Harvesting
The vast majority of Japanese tea is harvested with the assistance of machinery. This can range from various tractor-style vehicles that are driven over or alongside the tea, to handheld cutting machines resembling hedge trimmers, held by one or two people. Only a small minority of tea is hand picked, which is a significantly more time consuming approach with a drastically lower yield. Experienced pickers can pick around 15kg of tencha per day (which will yield as little as 1kg of matcha after processing and grinding). By contrast, a two person handheld machine can yield 250kg per day. As you can imagine, the condition of the harvested tea leaves depends on the harvesting method. During one of our visits to a tea farm in Yame, Fukuoka, hand picked leaves were be collected in small baskets with a capacity of around 2kg, periodically taken to a nearby truck. The truck provided shade and had fan ventilation to minimise damage from overheating while the leaves were taken to the sorting area. The truck was weighed upon arrival and again after depositing its harvest to document the weight of each deposit. In spring, the busiest season by far, there can be long queues of tea waiting to be steamed!

Steaming, Drying, & Sorting
Tencha goes through a short, high temperature steaming for around 30 seconds. This process stops enzymes from oxidising the tea and ‘locks in’ freshness. After steaming the tea is saturated with water, and must be dried. The next step is using air to blow the leaves, removing surface moisture and unsticking them from each other. This is achieved using large fans and netting that can be 6 meters tall or more, almost resembling an indoor skydiving setup! The tencha is then moved on to the tencharo - an extremely large oven for further drying the tea, which moved through on a conveyor belt system. The tencharo makes the tea dry and crispy. The stems, veins, and other byproducts need to be separated, and the tea leaves are cut into smaller flakes. The tea is assessed by the chashi (tea master), and potentially blended with other cultivars to form a blend. At this point though, high quality tencha will not be released straight away, but will undergo an aging process at low temperatures called jukusei, which rounds out and deepens the flavour profile of the tea. Jukusei can take many months, and is the reason why most high quality matcha is usually released around November, not in the spring time. The tea will then be ground to order. If you are enjoying freshly ground matcha in September/October it may be the last of the previous year’s harvest, aged the longest and with a deeper flavour profile than that same matcha that was released the previous November or December!

Grinding
With quality matcha there is only one option for grinding - stone milling with an ishi usu (traditional stone mill). It is the slowest option with the lowest yield, but critically the slow grinding avoids the build up of heat from friction, which would damage the delicate flavours of the tea. In chilled rooms to slow down oxidation, stone grinding yields just 30-40g of matcha per stone mill per hour, with a particle size of around 6-7 microns (thousandths of a millimetre). Jet milling uses high speed jets of air or other gases to break down the tea into smaller pieces, and can achieve smaller particle sizes (see matcha that is advertised as ‘soluble’ or ‘no whisking required’). Ball milling uses a rotating drum filled with metal or ceramic balls that will grind down the contents over time. Both jet milling and ball milling achieve dramatically larger yields, much quicker than stone milling.

Judging
In Japan tencha is evaluated at competitions by tea masters, but matcha itself is not evaluated. It may come as a surprise to hear this but when evaluating tencha, boiling water is used together with a long infusion of 3-5minutes! This is in an attempt to draw out any imperfections and harsh flavours, which more easily allows the judges to look for faults in the tencha. This allows the tencha to then be appropriately priced, and/or blended with other cultivars to achieve a specific flavour profile that the chashi is looking for. From our experience tasting a range of tencha with a 10th rank chashi, we can tell you that it is possible for high quality tencha brewed this way to have a bright, clean taste with zero bitterness or astringency whatsoever (yes, we were blown away!).

Summary
To sum up, tencha goes through the process of shading, harvesting, steaming, drying, sorting, storing, and stonegrinding, before it can finally be called matcha!

Hopefully you will have a better idea why "authentic" matcha is rare and expensive. 

In the next blogpost we will talk about some of the things you should pay attention to or should avoid when purchasing matcha.

P.S. Thank you so much for taking the time to read our blog post. We fear nowadays anyone can set up a matcha company without real understanding of the work involved in growing and processing tea from tencha to matcha. We hope we can bring a more educational side to those who are interested in matcha, by overcoming the language barrier - a big barrier to entry in the understanding of quality tea and quality matcha.

P.P.S. All words are our own, and although our knowledge is built up from years of research and visits to many tea farmers, the accuracy can not be 100% guaranteed, though we will correct any inaccuracies if any are spotted over time or if any are pointed out to us. All photographs have been taken by us during our many visits. Please do not quote this blog post for commercial purposes, or reuse any of our photos, without permission. Thank you! Our email address is:

info@cha-ology.com