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Friday, June 18, 2010

TEA Processing

Japan’s Matcha Tea: A Short Primer
By Robin Stevens
Japanese matcha tea has been traditionally used for over 1,000 years, and is increasingly incorporated in modern beverages and products. Stevens explores the traditional and modern uses of matcha, along with the production process and advice for purchasing and preparing matcha tea.

Japanese tea often inspires a vision of the brilliant, emerald-hued powdered tea used in the Japanese tea ceremony. With a history dating back over 1,000 years, matcha tea has enjoyed one of the most revolutionary product life cycles in the industry. As this healthful tea gains popularity worldwide, it’s finding a home in a variety of novelty beverages served up in coffee houses and juice bars, and blended into beauty aids, nutritional supplements and avant-garde food products. From Rishi Tea’s individually packaged Matcha, 100% Premium Tea Powder to Cappuccine’s Matcha and Blueberry Matcha Frappés and Origin’s The Way of the Bath Matcha Tea Body Scrub, the uses for matcha have multiplied exponentially. Indeed, armed with some of the most definitive scientific research in the industry, those who produce and market matcha stand on firm ground when they say that it is among the most healthful products a person can “eat.”
What is Matcha? 
Traditional matcha is a premium Japanese green tea made from shade-grown tencha leaves that have been de-veined and ground into a fine powder using a stone grinder. It is only harvested once a year and is whisked in hot water rather than steeped before it is served. Because matcha consists of finely ground tea leaves, when you drink it, you are consuming the plant as you would a vegetable. According to Aiya Co., Ltd., one of Japan’s oldest and most respected tea companies, the body’s uptake of nutrients from matcha is about 65%, compared to just 35% when drinking ordinary tea. Only a small percentage of water-soluble nutrients can be extracted from the leaves during the traditional steeping process.
Typically matcha is produced in Japan, but now some companies like Aiya have established tea fields and processing facilities in China in order to expand the number of organic matcha sources available. However, the finest matcha is produced on farms in Japan that date back hundreds of years. While true matcha is made from tencha tea leaves, other powdered teas may be made with sencha or lower grades of green tea. These teas can be distinguished by their darker and sometimes flatter green color and less desirable taste profiles. They are usually more astringent and not as sweet as traditional matcha. Although most producers and importers are honest and differentiate between the matcha and powdered green tea products they sell, buyers beware. It is important to purchase matcha from reputable suppliers not only because it is highly specialized and expensive, but also because a number of imitation products are on the market that may contain sugar, food coloring or even MSG.
A Short History of Matcha 
The tea ceremony is an integral part of Japanese culture and history. Its origins are in China, but it was refined into an art form with a strongly spiritual emphasis in Japan. Japanese monks who had studied Buddhism in China introduced tea to Japan just prior to the Heian period (794-1192 CE). It was initially used as a medicine and also as a means to stay awake during meditation.
During this same period, Lu Yu (ca. 733-803) wrote the seminal Tea Classic (Cha jing), in which he described the origins of tea, its cultivation, preparation, tea equipage and other tea-related matters. Aside from the great historical and cultural contribution Lu Yu made in writing this book, his emphasis on the spiritual and ritualistic aspects of tea survive today in the Japanese tea ceremony.
At the end of the 12th century, Eisei, a Japanese Zen monk introduced to Japan the powdered tea that was in vogue during China’s Song dynasty (960-1127 CE). The tea was ground into a fine powder and whisked into a froth before it was drunk. Later, during Japan’s Muromachi period (1392-1573), matcha gained favor with the samurai class, for whom tea ceremony was a cultural commodity that could help elevate their social status. Feudal lords, or daimyo, retained tea masters and collected tea utensils, which were considered prized cultural possessions.
The rules for handling and serving tea were codified in Zen Buddhist monasteries during the 15th and 16th centuries. Sen no Rikyu (1522-1591) is best known as the Japanese tea master who formalized the rules of behavior and standards for tea ceremony known as chanoyu. These principles and rules of etiquette endure almost in their entirety to the present day. He was very influential and served as tea master to two of the most powerful men of the period, Oda Nobunaga (1534-1582) and Toyotomi Hideyoshi (1536-1598). Thus, tea ceremony and its experts were elevated to the highest cultural status in tea history during this time.
How is Matcha Produced? 

Tea plants prior to shading
Matcha is made primarily in the Aichi and Kyoto prefectures in central Japan, near the cities of Nishio and Uji, respectively. Its complicated production methods make it one of the most expensive teas in the world.
The most suitable tea varietals for producing matcha are yabukita, samidori and okumidori. The long process of production starts many years before the leaves can actually be used to make matcha, beginning with planting the seedlings. The soil is tilled to a depth of two to three meters before they are planted. Afterwards it takes five years of growth and another two years of test harvesting before the plants reach maturation.
The tea leaves for matcha are plucked just once per year, starting approximately 88 days after setsubun, a celebration marking the end of winter that traditionally occurs on February 3rd. About four weeks before plucking, a shading process begins that typically involves applying three layers of shading over the plants, one layer per week depending on the weather. A fourth layer may be added if the leaves are to be used for ultra-premium tea. The shading consists of black vinyl sheets that are rolled out onto a large network of frames that rise above the tea plants.
The shading process forces the plants to struggle for the light they need to grow. This results in longer, thinner and softer buds rich in chlorophyll and amino acids, which gives matcha its naturally sweet flavor and mutes the effects of caffeine. Fumi Sugita, president of Aiya America, explains, “The amino acid L-theanine works in conjunction with caffeine to produce a three to six hour energy rush, without the crash that people experience when they drink coffee.”
When the leaves are ready, the youngest shoots are selectively hand-plucked. This starts the basic refining stage, during which the leaves are referred to as namacha. The leaves are transferred to a processing facility within 12 hours of plucking where they are steamed at about 100ºC for approximately 20 seconds to halt enzymatic activity and prevent the leaves from oxidizing, helping to lock in the nutrients. Then the leaves are dried for about 20 minutes at 140-150ºC. Although tea masters control the environment to the greatest extent possible, the quality of the leaves and weather affect the length of time and the temperatures used during the steaming and drying process.
After drying, foreign particles are removed from the leaves, and then the leaves are called aracha. It is at this point that the processing methods for matcha and gyokuro, Japan’s premium loose-leaf tea, diverge. The leaves used for gyokuro are rolled and shaped in the next stage of processing, while leaves for matcha undergo a process in which all the stems and veins are removed by a mechanical separator. The cut leaves are blown through a horizontal blower and only the fleshy, middle part of the leaves are collected for the next stage of processing. They are then heated in a roasting machine at about 95ºC for 15 minutes to reduce the moisture content of the leaves to approximately 4-5%.

Mechanical Grinders
Once the leaves have been separated and roasted, they are called tencha. During this third and final phase of processing, tencha leaves from different farms may be blended to achieve consistency and stabilize flavor and color. Then they are ground into a fine powder. Traditionally this was done by hand using a mortar and pestle, but now producers use mechanized granite grinding wheels or air pulverization. However, air pulverization causes friction, which can result in the loss of nutrients, so grinding wheels are more optimal. Even with mechanical grinders, grinding is a lengthy and slow process that takes about a hour to produce about 30 grams (1.06-oz) of finished tea.
After grinding, the tea is sifted through a fine mesh filter, ensuring a consistency similar to talcum powder. Then the tea is carefully packed in a sterile room much like the clean rooms used in the silicon wafer industry. According to Shiro Nobunaga, the regional sales director of Aiya America, matcha has a one-year shelf life if it is sealed in airtight containers and refrigerated until sold. After it is opened, it is best to use it within one to two months because the color, flavor and aroma begin to change almost immediately after being exposed to light and oxygen.
Sourcing Quality Matcha 
Quality ratings for matcha range from ceremonial grades used for tea ceremony to several levels of food grade matcha. The highest food grades are used in ice cream, lattes and cakes or other sweet foods, whereas lower grades are suitable in items where taste and color are a less central factor, such as power bars, cereal and supplements. Imitation powdered green teas are used in a variety of ways, but overall the flavor, color and aroma are less stable and they tend to be bitter or overly astringent.
One of the most important factors in sourcing matcha is knowing the difference between matcha and other green tea powders. Shiro Nobunaga of Aiya recommends verifying the origin of the tea and the production methods used, obtaining lab analytics from suppliers and conducting sensory testing. Because matcha is so expensive, it is worth the time and effort required to identify a consistent and reliable supplier.
Sensory testing for matcha includes the same key factors as loose-leaf tea, including evaluation of the color of the tea in its dry state, its aroma and flavor. The best matcha is a brilliant jade green when it is dry and a deep jade green when mixed with water. Some tea producers such as Aiya use color spectrum analyses to help make quality distinctions. These analyses provide ratings along a continuum that indicate the brightness and depth of the tea color for a given batch of matcha.
The aroma of good matcha should be slightly vegetal and the flavor smooth and sweet. It may have a light astringent taste or none at all. Fumi Sugita of Aiya says, “If the leaves are not steamed long enough, the color of matcha is a nicer green but it may have a grassier flavor. Conversely, if the leaves are steamed too long, the taste is better but the leaves may turn red, impacting the color profile of the finished tea.” Amino acid and catechin content also affect the flavor of matcha. In general, the higher the amino acids, the sweeter the tea is. If the tea is bitter, then it probably has lower amino acid content and more catechins.
Buyers should also consider other factors. The particle size of the tea should be between 10 and 15 microns. If larger than 15, some leaf particles may be visible, making for a grainier cup of tea. The ideal moisture content of finished matcha should fall between 4 and 6%. Ideally producers also analyze their tea for factors such as yeast, mold, bacterial content and pesticide residues, so it is important to check on the availability of this type of information. Nutritional analyses provide yet another quality indicator to consider. Matcha contains a wide range of nutrients, including calcium, iron, vitamins A and C, as well as protein and fiber. The nutritional content varies based on the overall quality of the tea.
Preparing Matcha 
There are many nuances in the ways that matcha can be prepared and served, in part because making and sharing tea with others is regarded as a deeply unique and peaceful experience. It is said that it takes a lifetime to understand and know chanoyu, the Japanese tea ceremony, which involves a broad range of artistic elements including painting, calligraphy and flower arrangement, as well as knowledge of incense, food, etiquette and so on. For beginners, there are some basics to be aware of, namely the distinction between koicha and usucha, and that preparation methods differ depending on such factors as occasion and season.
Koicha refers to thick tea; usucha is thin tea. Only the finest matcha is used to make koicha because the tea is so thick, it is almost like a paste. Double the amount of matcha is used to make koicha compared to usucha, while the amount of water is virtually the same. The flavor should be refined and sweet, with a creamy mouth feel. If lower quality matcha is used for koicha, it might be bitter, which would be highly undesirable. Koicha is reserved for very special occasions, such as New Year’s ceremonies, while usucha is used more on a daily basis.
The terms misodana and kagetsu refer to two different procedures for preparing and serving tea. The misodana method is western style, in that participants sit in chairs; usucha is generally served. Shiro Nobunaga of Aiya says, “Kagetsu was traditionally a playful, game-like way of serving tea, often enjoyed among family and friends. Either koicha or usucha is served, and sometimes both.”
Seasonal variation accounts for some of the most important variations in chanoyu, because the tea ceremony represents the harmonization of natural elements and the refined. For example, the tea bowls used in summer are flatter and have more surface area than traditional bowls, allowing the tea to cool faster. The placement of the kettle is also different. During summer months, the kettle is placed on a furo (brazier), which is exposed and positioned away from guests to avoid making them feel hot or uncomfortable. In winter the kettle is placed on a ro (sunken hearth), which is embedded in the floor between the guest and host to share the warmth.
Despite these multifaceted approaches to tea preparation, one can still make a good cup of matcha in a peaceful and respectful way. To demonstrate how to prepare matcha for one person, first heat the water to just below boiling point, about 175ºF. If the water temperature is too high, it destroys the nutrients and extracts the bitterness in tea, whereas cooler water enhances the sweetness. Warm the tea bowl by swirling a bit of hot water in the bowl. Dip the whisk into the water to heat it, and then pour off the water and set the whisk aside for a moment. Measure about half a teaspoon of matcha into the bowl and add about 2 oz of water. Experienced tea drinkers may use larger quantities of tea, but usually no more than 1.5 teaspoons. Stir the tea a couple times with the whisk using a wide sweeping motion, and then briskly whisk it about 15 times. This whisking motion is not circular, like the way westerners usually whisk scrambled eggs, but rather a tight, slightly forward and back motion. According to Nobunaga, if you finish the whisking by forming the number six in the bowl and then pull the whisk straight up out of the tea, it makes the foam spread more evenly. The tea can be served in the bowl or transferred to a cup. Either way, it is best to drink it immediately in order to appreciate the aroma and flavor, and to prevent particles from settling at the bottom of the bowl as it cools.
Finding the Right Fit 
Matcha is truly one of the industry’s most versatile teas. Coffee houses and juice bars, ice cream shops and other types of retail establishments already offer a variety of custom and pre-blended food items, smoothies and tea and juice drinks. Michael Rubin, president of Cappuccine, reports that their Matcha and Blueberry Matcha Frappé blends, launched this spring, have been very well received. Asked why Cappuccine chose to use the more costly matcha instead of ordinary powdered tea, Rubin says, “Quality, which translates to great taste. We will not release a new flavor unless we believe that it is the very best tasting of that type of product in the world.”
However, to really grow the market, more education is needed. Professionals at all levels of the industry can help wholesalers, buyers and consumers learn about this distinctive tea through informal educational events, sampling and innovative marketing and sales materials, such as POPs with tear-away instructions for matcha tea preparation.
Restaurants and tea houses can join the trend by preparing and serving matcha in interesting and lively ways. For example, in Asia, servers often prepare specialty teas for customers at their table. This type of transparency has been used successfully for food preparation and service in other American contexts, from Krispy Kreme’s in-store displays of its automated doughnut-making machines to hand-thrown pizza dough and tortilla making in specialty restaurants across the country. People love to watch how things are made. Likewise, tea can be an experience; indeed, the experience is essential since many people do not know how to prepare such teas by themselves. However, it is important not to discourage people by making tea or the tea-making process seem overly complicated. As most tea masters will tell you, tea is really about hot water and leaves. Their point is that making good tea is a simple process that provides an opportunity to slow down and pay attention to the spirit, and to appreciate all that the moment can provide - at the minimum, a delicious healthy beverage, and at its best, a window to nature.
Robin Stevens is a former Fulbright Scholar to Taiwan and specialist in tea house culture. She is based in Southern California where she is a freelance writer and conducts educational tea tastings at private and public events. All photos are courtesy of Aiya America Ltd.


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