16th September 2022
Meet The Maker: Inside a Japanese Tea Refinery with Natsumi Osada

Organic tea minimises exposure of land, wildlife, producers and consumers to agrochemicals
Japan is revered for its tea craft, with bold green teas and unique blends that are rich, grassy and full of umami, as well as being deeply aromatic. The highest quality examples of these teas are skilfully refined and use only the best leaves - carefully harvested and processed. Our latest batch Organic Genmaicha is one such tea, a traditional blend of warming, organic brown rice and spring-fresh sencha. So, I was excited to spend some time speaking to the people who helped create it and discover the story behind the craft.
Catching up on video call, I met with owner, Natsumi Osada, along with product specialist, James Johnson of Osada Tea – the refinery team behind Organic Genmaicha. Speaking at the end of their busy summer flush season, there was much I was keen to discover - what life in the Japanese tea industry is really like, the future of organic tea in Japan and ultimately, what it takes to make great tea.
We begin with a cup of tea and as I get settled in with a morning cup of sencha, on the other end Natsumi and James enjoys a cup of caffeine-free herbal infusion, as they finish up for the day. They’re currently at the Osada tea factory HQ in Mori-Machi, nestled in the peaceful countryside of western Shizuoka, Japan. "As usual, we’re here working every day till 7, 7:30pm" says James with a smile.

A birds-eye view of the Marusen Isagawa tea gardens

Roasting and sorting machines inside the refinery at Osada Japanese Green Tea

Organic Japanese Green tea bushes in the garden
The tea refinery has an important role in the Japanese tea industry. That because there are two stages for tea production in Japan. James explains the basics – Firstly, the leaves are harvested at the tea garden and carefully part-processed by the farmers. This creates what’s called aracha meaning ‘crude’ or ‘half-finished’ tea. The aracha is then sold to tea refiners who use it craft a variety of finished teas using shiyage (refinery) processes, like leaf sorting, roasting, steaming, blending and drying. "Both the aracha and refinement are an art and a science," says James. For an even better understating, I’m whisked on a quick virtual tour of the building and refinery...
"Here at the HQ we have tea appraising rooms, dining hall, a meeting room and the shiyage (refinery) factory” explains James “so it’s kind of a combined office space and factory."
There’s impressive machinery with lots of moving parts, but in all Osada is really a humble family business, with a team dedicated to expertly overseeing the operation. Natsumi himself married into the business and has been working as a tea refiner for 20 years now. He also holds a 9th dan tea instructor certification. No mean feat. Gaining the initial certification takes years of study and tedious exams on everything from tea history to agriculture and economics. Natsumi certainly has a competitive spirit. In 2009, he took overall victory at the National Japanese Tea Examination and Technology Competition and received the Minister of Agriculture, Forestry and Fisheries Award in successive years. James also passed the arduous tea instructor exam in 2021 – only the second American to do so - and I ask him what it takes,
"Tea instructors are really the point of reference for correct information about Japanese tea. It’s a big test and it’s not easy, a lot of people don’t even get past the first exam. But it was a fun process, my head felt so full every day. But even passing the exam is just a starting point, working in the industry you see a lot of things that you don’t learn from a book - ways of saying things, talking to farmers, setting prices... real experience is definitely important."
James joined Osada a year and a half ago and has settled in the countryside working at the refinery. I ask him how his current experience of Mori-Machi differs from life in the US.
"It’s so different to how I grew up, Mori-Machi full of nature, the Ota river runs right through the centre of town." He says. "In Japanese they have the word ‘shigeki' which means stimulated. Even after a year and half living here, it lifts me up while I cycle to work and back every day."
Often likened as a mini Kyoto, thanks to its beautiful setting and historic shrines, Mori-Machi is also well positioned for tea production. It’s a short 30 minute drive straight north into the mountains of the Tenryu district, where many of Osada’s partner tea gardens can be found. A further hour up into the high mountains and you reach the isolated Marusen Isagawa Cooperative gardens. A collective of organic tea farms surrounded by nature and sitting at 300m – 450m in altitude. The organic green tea from the cooperative’s spring and summer 2021 harvest was refined and blended for our latest batch of Organic Genmaicha. I ask head refiner Natsumi Osada about his work with the Isagawa tea farmers and how they go about choosing their aracha during the busy season.
"The style here is a little bit different to the rest of Japan, it’s much more about negotiation and talking to the farmers," explains Natsumi "After plucking the leaf and making the aracha during the night, the farmers will bring us small batches at, usually, 4 or 5 in the morning. When we settle on a tea they can then bring the daikai (big bags) of aracha to us. During the busy season we’ll work from 4am till 9pm most days."

Tea leaf sorting machines in the refinery
Working so closely to the farmers and nurturing their connection means that Natsumi can get first choice on the best teas as fresh as possible, while continuing to support the local, organic agriculture.
"A lot of tea from the local area will come to us, around 70% of our teas are local and built off of good relationships with farmers. When they bring the samples we always talk about cultivars, methods and how they’re gardens are going. But I’ll be honest with them about their tea, if something is not right, the taste or colour is off, I’ll say so, because we always want to build an honest relationship."
Once they receive the aracha James explains the rough shiyage (refining) process. Beginning with unloading the heavy 3kg bags of leaves. "Then an initial sorting machine will create uniform material before the leaves are sifted to separate the larger and smaller sizes. Once they’re separated the tea moves on to roasting, which can be hard or light depending on the taste profile and tea we want to create - black tea, matcha, kukicha etc. We then separate the stems from the leaves using either static electricity a CDC camera which uses a laser to detect the thick stems and then shoots air to blow them from the leaf. It’s an interesting process."
The conversation then turns to Organic Genmaicha, a classic blend of organic rice and steamed green tea. James tells me it’s a popular tea in Japan and I’m curious to know more about what makes it so special.
"Genmaicha is really simple and approachable, it’s just brown rice and sencha, but it’s a highly aromatic tea that’ll fill the room.” James tells me, “Frankly being American I like things with a heavier flavours, so when I’m tasting sencha I often think it’s ‘nice’ but can be lacking in flavour, genmaicha fills that need for flavour,” He continues, “It’s also versatile, you can make it with boiling water, you can cold-infuse it, or even add some matcha powder to it to bring out that green taste.” Natsumi jumps in “We put a little bit more effort into our Genmaicha than the average producer. We make sure to get good rice and use the high quality spring flush sencha, the process is very detailed."
One important aspect of their genmaicha is that its certified organic. We often hear from producers that there is not much demand in the market for organic products Japan. But James tells me that for them, organic is something they’re really interested in, which is why they partnered with the organic Isagawa Marusen cooperative.
"The farmers have a know-how and an understanding after 30 years of doing this, there’s even some young guys farming now too. I think a lot of it comes down to nature and working with the seasons. It’s a lot of monitoring and planning ahead for the next season, because they’re not using chemicals they have to be more keen to how nature reacts through time." Says James.

A birds-eye view of the Marusen Isagawa tea gardens
Despite their knowledge and efforts the farmers still face new challenges each year and Natsumi is keen to explain the effects of climate change that he has been hearing.
"They tell me that yabukita, the main cultivar, is getting harder to produce because of climate change. With the rising temperatures the tea leaves will start budding earlier than usual, during the frost period, which can cause damage and be a problem for the new shoots.” He explains, “But they’re trying to make more use of different cultivars lately which can be used for different kinds of tea like Japanese style oolong,".
As we finish up our conversation, the two are hopeful that even though organic is "not such a big thing" for customers in Japan, the farmers love it, "It’s what you're not putting in the tea that makes it tasty" James quips. As for tasty tea, I can’t help but finish by asking them their favourite way to enjoy Genmaicha. James advises...
"Use a clay teapot, around 800ml with about 3g per person - as a good rule of thumb - and infuse for about 30 seconds, so fairly quick. You want the water hot enough so the steam fills the room with the Genmaicha aroma."