In addition to being Japan’s most famous tea, matcha is also its oldest, and one of the oldest types of tea in the world, with proto-matcha dating all the way back to Song Dynasty China (960-1279). Both tea plants themselves and the practice of whisking powdered tea with hot water were brought to Japan from China in the 1100s and after the development of artificial shading in the mid-1400s, modern matcha was beginning to take shape.

Although the exact methods of production have changed since the 1400s, the basic steps remain more or less the same: shade, pick, steam, and dry to produce tencha (碾茶 - tea to be ground); then sort and grind this tencha into matcha (抹茶 - ground tea). Here, we’ll take a look at how modern matcha is made and how each step along the way can have its unique impact on the final product’s quality and taste.

Fig. 1: Matcha Production Flowchart

The exact production flow can vary significantly across regions and between different farmers and producers, and it would be imprudent to overgeneralise, as the diversity in styles and practices is part of what makes this tea tradition so endlessly intriguing. So for this overview, we’ll take a broader look at the overall process, with deep dives on all of the variables at each step in separate blog posts. To make things as simple as I can, let’s break up the production process into three distinct phases:

1. Cultivation: growing, fertilising, shading, and harvesting

2. Crude Production: steaming, cooling, de-stemming, drying

3. Finishing: sorting, refining, blending, resting, grinding

Cultivation - (栽培 - saibai)

Fig. 2: Tea leaves under straw shading

One of the many variables is the cultivar of the tea plant. The tea plant, Camellia sinensis exists in five varieties, two of which, Camellia sinensis var. sinensis and var. assamica, are grown commercially to produce tea, and each of these has hundreds of sub-varieties and cross-breedings that have been selected to become clonal cultivars.  While matcha can technically be made from any of these plants, the tea plants in Kyoto have been bred and selected over centuries to encourage certain traits desired in matcha. The best of these plants were then developed into clonal cultivars such as Asahi, Samidori, Gokou, and Uji-Hikari. These special cultivars have excellent flavour, but typically have lower yields than more common varieties, such as Yabukita or Okumidori.

Shading

Fig. 4: 'Naturally-tailored' tea plants under fabric canopy shading

The defining feature of tencha cultivation is shading, the goal of which is to reduce the amount of sunlight hitting the leaves. This has the effect of making them sweeter, more umami, and less bitter, while also turning them a darker, more vibrant shade of green. Additionally, shading makes the tea leaves thinner and softer, making them easier to grind. Farmers typically start shading two to three weeks before they expect to harvest, starting with one layer of shading, before ramping up to two. There are a few different ways to shade tea plants, each with their own benefits and caveats, which I have covered here, but in short, expensive canopy style shading, whether using straw or fabric, produces better quality tea, but is much more expensive and difficult to set up. Shading the tea plants directly is much easier, but can trap heat and humidity, lowering the final quality. A more extensive look at the biology and chemistry of tea shading can be found here.

Picking

Fig. 5: Hand-picking naturally-tailored plants under canopy shading

Determining the right day to harvest is one of the most important skills of the tea farmer and it is influenced by a handful of factors, such as the weather patterns or the plant’s cultivar. Additionally, depending on the style and quality of the tea they want to make, the farmer can choose to pick the tea earlier when the leaves are a little smaller to prioritse quality or they can wait until they grow bigger to get a larger yield, at the expense of flavour. Usually some compromise in between is ideal. Ultimately, the farmer can tell when the tea is ready by how the leaves feel in the hand.

If the tea plants are grown in the hedge-row style, they can be harvested by machine, which is much faster and less labour-intensive than hand-picking, but has the downside of being less discerning, often harvesting old leaves or other undesired material. In the rarer plots of naturally-tailored tea fields, hand-picking is the only option, with the more discerning fingers of the tea picker selecting only the young, tender leaves.

Whether it’s by hand or machine, tencha is typically picked later than sencha or gyokuro as the farmers want the leaves to be broader, to make them easier to de-vein and grind into matcha. 

Fig. 6: Basket of freshly hand-picked tea leaves

Tea plants continually produce new leaves from spring to autumn, and can be harvested multiple times a year, but for green tea and matcha in particular, the first harvest or spring harvest, is the most desirable as the tea leaves are softer and more flavour dense with the all of the nutrients stored and absorbed over the winter. For the highest-quality matcha, the tea bushes are only picked once per year in spring, having the rest of the year to build up flavour once again for next year. In Kyoto, tencha harvest is typically in late April to mid May

Now that they’re harvested, the leaves go straight to the factory, to undergo crude production.

Crude Production - (荒茶 - aracha)

Fig. 7: Preparing freshly-picking leaves to be steamed 

The freshly-picked leaves are taken to the tencha factory (碾茶工房 - tencha kōbo), specialised to processing facilities that have the required machinery to produce tencha. These are much less common than the factories used to produce sencha and other leaf teas. 

Steaming

Like almost every Japanese green tea, the goal is to keep the tea as fresh and green as possible. If the leaves were left alone, they would slowly wither and begin to oxidise. In order to lock in as much freshness and greenness as they can, the leaves are steamed right away. The heat of the steam denatures the enzymes that cause oxidation, thereby preventing any oxidation from occurring and preserving the vibrant colour, flavour, and aroma of the fresh leaves. 

Cooling

Fig. 8: Cooling freshly-steamed leaves 

Residual heat from steaming can degrade flavour and any surface moisture left from the steam can cause the leaves to stick together, making them harder to process and leading them to dry unevenly. To cool and separate the leaves as quickly as possible, they are blown up and down a series of tall nets immediately after leaving the steamer. 

Drying

The leaves leave the cooling nets spread evenly in a single layer to further encourage even drying as they head towards the tencha ro (碾茶炉 -tencha furnace) which is heated to around 200°C (392°F). The leaves enter the lowest and hottest part of the furnace first before travelling further up the furnace, zig-zagging roughly 10m (30ft) of conveyor belts for around 30 minutes. The goal here isn’t to roast the leaves or impart any flavour, but to dry them evenly and preserve their flat shape for ease of processing.

De-stemming

Fig. 9: Aracha Tencha (note large leaf size) 

Although the leaves are dried as evenly as possible, the anatomy of a leaf means that they can never be perfectly even: the thicker stems retain more moisture than the blade of the leaf. In other Japanese green teas, this is rectified by rolling and kneading to squeeze the moisture out of the stems and into the blade, evening it out. However as tencha is intended to be ground into matcha, the solution is to remove the stems entirely as they do not grind easily and degrade the final colour of tea, being of a whitish colour. To separate the stems, the leaves are mechanically cut down into small flakes. The stems can then be separated from the leaf flakes using various techniques, typically winnowing, and dried again separately. Due to their white, stick-like appearance, in the tencha industry, the separated stems are called hone (骨 - bones). At this stage, the tea might look like it is ready to be ground into matcha, but at this point, it is still considered aracha (荒茶 - crude tea), and must be further processed before it is ready to be ground.

Finishing - (仕上げ - shiage)

Fig. 10: Refined Tencha (note even leave size and lack of veins)

From here, the aracha has a few different paths it can take to become finished matcha. In rare cases, the farm is large enough to own or rent a finishing facility and can process and sell their matcha themselves, but in the majority of cases, small farms sell their aracha to a wholesaler or producer who finishes and sells the tea. Historically, this person was known as a chashi (茶師 - tea purveyor), the intermediary between the tea farmers and the samurai/shōgun/daimyō/merchant/temple ordering the tea. While this term is still used occasionally today, some of their responsibilities have evolved. There are two ways farms can sell tea to chashi: at the wholesale market or directly.

Buying Aracha

The annual tencha market is the standard venue for farmers to showcase their aracha to potential buyers. This market is open to tea professionals only and operates on a blind auction system, with representatives from different tea producers sampling and evaluating hundreds of aracha tencha before bidding on them. The ability to judge the quality and flavour of a tea when it is at this crude state is one of the most difficult aspects of the matcha production process, as the tea will undergo many changes in flavour as it is finished, rests, and is ground into matcha.

Direct sales (入れ着け - iretsuke ), was the standard system for centuries before the first market opened up in the early 20th century. With iretsuke, instead of selling their tea at auction, farmers have direct annual contracts with the matcha producers who agree to buy their tencha every year for an agreed upon price. This enables lower prices for producers, guaranteed customers for the farmers, and a direct collaboration between the two. The downside is that the unpredictability of agriculture could leave a matcha producer buying lower-quality tencha than they would for the same price at market.

To balance this, many matcha producers use both systems to acquire their tencha each year: maintaining a steady relationship with trusted farmers while buying additional tencha at the auction to round out their blends or fill in any gaps that their direct relationships couldn’t provide.

Refining

Fig. 11: Manually cutting tencha to size using a metal mesh 

The exact order of steps varies per producer, but the general goal of refining is the same. The leaves are cut down further to make the flake size consistent. This is typically done mechanically, but is still done manually by some producers. After cutting, the leaves can be further sieved and refined, passed through multiple sizes screens  and winnowers to even out the size and remove any unwanted material such as remaining stems, veins, old leaves, or foreign matter. Finally the tencha is gently dried for a final time to reduce the moisture content even further. Here, more heat can be added if the producer wants to bring out a more roasty, nutty aroma, or it can be kept gentle to preserve fresher, greener aromas.  

Blending

Fig. 12: Tasting tencha to determine blend ratio 

Either before or after the refining stage, the producer develops their blend. Blending allows chashi to craft teas that are more than the sum of their component tenchas. A single tencha might have a fantastic colour, but be lacking in aroma or flavour. By blending tencha with different strengths, a producer can balance out their weaknesses and craft an overall tastier matcha, often for cheaper than a single origin tea of the same quality. Blending can also help tailor the flavour for an intended use case: prioritising smoothness and umami for koicha, perhaps more aroma for usucha, and a strong colour and milk-piercing flavour for lattes. 

Typically, the flavour profile of a particular blend has already been developed years ago and the producer purchases tencha each year with the goal of recreating this profile and keeping the taste consistent: blending new harvest tencha to reproduce the same flavour they achieved last year. This isn’t as simple as mixing the same teas from the same farms in the same ratios, because the flavour and quality of each component tencha varies considerably year-to-year. In addition to their ability to evaluate raw tencha at the market, tea producers’ ability to craft consistent blends year after year is one of the hallmark skills of traditional matcha production, especially in Kyoto.

Of course, in the case of farmers that process their own teas, some choose to bypass blending altogether, and simply process a matcha as single cultivar and single origin. This has the upside of showcasing their efforts more transparently, but can lack the polish and refinement of a traditional blend.

Resting

Fresh tea leaves have a vibrant, grassy, verdant aroma, which is desirable in sencha, but less so in matcha. To countermand this, producers traditionally allow the tencha to rest and mature in cold storage for around six months before releasing it for sale. This allows the volatile leaf alcohols responsible for that bright, grassy aroma to dissipate, allowing the more complex aromas that remain to shine through. The resting (熟成 - jukusei) of tencha has been practised in Kyoto for centuries, but production regions that are new to producing matcha, such as Shizuoka or Kagoshima, aren’t as steeped in Kyoto tea culture, and often skip this step.

Some producers blend the tea before resting it, but many keep the tencha separate while resting, in case they mature differently, giving them the flexibility to adjust the blend if needed. After the resting period is up, typically in autumn, the tencha is taken out of cold storage and is ready to grind.

Grinding

Fig. 13: Stone-grinding tencha to produce matcha 

Employed for over 800 years, the standard method of grinding matcha is still the stone mill (石臼 - ishi usu). There have been very few modifications to the design over the centuries, one of the most convenient being the addition of an electric motor in 1912. Even with the help of electricity, one stone mill can only produce 30–40g of matcha per hour. If the mill stone were bigger or the mills were spun faster the friction generated would overheat the tea and degrade the flavour. To counteract this, modern matcha milling facilities are typically located in a refrigerated room, to keep the tea as cool as possible. Still, the only way to grind matcha faster on a stone mill is to use…more mills.

While matcha sold as usucha or koicha is almost invariably ground using a stone mill, cheaper usucha and matcha blended for lattes or culinary purposes make use of more modern technology to be ground on a larger scale. The most common of these technologies are ball mills, consisting of a rotating drum that pulverises the tencha using steel balls. These can grind around 125g per hour, but generally don’t produce grinds of the same quality as a stone mill.

More recently, bead mills, which use tiny ceramic beads to pulverise the tencha, can output between 10,000–20,000g of matcha per hour. When set up correctly, they can achieve the same 10 micron grind size produced by stone mills, although the microscopic structure of the ground tea particle often differs from stone milled tea, in a way that can negatively affect texture and flavour. For this reason, stone mills are still seen as the golden standard for quality, despite their slow speed.

At last, the tea is ready to be packed, shipped, and enjoyed.

Fig. 14: Preparing usucha in the tea room 

As you can see, matcha quality and flavour is incredibly complicated, with each step of this process having its own effect on taste, aroma, and colour. Reducing these complexities to a false dichotomy of ‘ceremonial’ or ‘culinary’ ignores all of the things that make each tea unique.

This is just a brief(ish) overview of the matcha production process. Each step has much more nuance than I was able to convey here, so I will revisit various parts of this production process in more details posts, such as the ones on shading and tencha cultivation.