How I Found the Tea Farmer Who Farms for Focus

In November of 2025 I travelled to Yame, a tea-growing region tucked into the hills of Kyushu, in the south of Japan. I went in search of the best gyokuro — the shaded, umami-rich tea that most people have never heard of. What surprised me is how many Japanese people haven't either. Outside Kyushu, whenever I brought up gyokuro or Yame itself, I was mostly met with polite blank looks. The finest tea in Japan, from a place much of Japan doesn't know. That's what I'd flown in for — a buyer on a mission, ready to be discerning. The small hotel I was staying at offered a tea experience one evening, hosted by a local grower, and I said yes expecting to taste, take a few notes, and move on.

The grower was Kakuda-san, third generation of a family tea farm called Kakuda Seicha. He sat with us and brewed his own teas, and somewhere around the second cup I stopped making conversation and just paid attention to what was in the cup.

With Kakuda-san of Kakuda Seicha during his tea demonstration in Yame, Kyushu — November 2025.

It was sencha — ordinary leaf tea, not matcha. But it didn't taste ordinary. It was sweet in a way sencha usually isn't, thick, almost savoury, closer to a broth than to what I think of as green tea. I'd been buying and drinking Japanese tea seriously for years by then, and this was doing something I couldn't place. I remember thinking, this man has a secret.

Then he started talking, and it turned out the secret wasn't a secret at all — it was an obsession. Kakuda-san wanted to talk about theanine.

Kakuda-san mid-explanation — this is a man who loves his subject.

If you haven't come across it, L-theanine is the amino acid in tea responsible for that sweet, savoury umami taste. It's also the compound behind the particular feeling good tea gives you — alert but calm, focused without the jittery edge of coffee. Taste and effect, the same molecule. What you're tasting when tea tastes sweet is, quite literally, the thing that settles your mind.

Here's what got me. I've sat with a lot of tea growers in Japan. They talk about their mountain, their water, their family's cultivar, the year's weather. That's the language of Japanese tea, and it's beautiful. But I had never — not once — sat across from a farmer who talked about theanine by name, as the thing he was deliberately farming for. Kakuda-san did. He shades his tea specifically to drive the theanine up.

Now, I want to be honest about something, because when I got home I told my supplier this story with a bit too much wonder in my voice, and he set me straight. Shading tea before harvest is not rare. It's a common, centuries-old technique — you cover the plants and block most of the light in the weeks before picking, and the leaf holds onto its theanine instead of turning it into the bitter compounds that sunlight encourages. Growers all over Japan do it, often to get better flavour out of flatter land. So Kakuda-san hadn't invented the idea. I'd been a little starstruck.

But here's why I still think he's unusual, and why I've thought about that evening ever since. Most growers shade because it makes the tea taste better and leave it there. Kakuda-san took the same technique and pushed it — deliberately, measurably — toward theanine itself. He didn't just do it by feel. He and his family, working with Professor Kenji Mishima at Fukuoka University, actually put it to the test in a lab. Their shade-grown leaf measured 2.52 percent theanine — higher than the 2.35 percent you'd expect from premium gyokuro, and above high-grade matcha too. In an everyday leaf tea. Their farm even describes its specialty, plainly, as cultivation focused on theanine.

A farmer who can taste the difference, and then goes and proves it in a lab. That combination is what stayed with me. It's the whole reason I care about where tea comes from — because occasionally you meet someone who is quietly, seriously chasing one specific thing, and you can taste the result before you understand it.

I've written before about my own experience with L-theanine and that clear, calm-focus state — how it changed the way I drink caffeine. Meeting Kakuda-san gave that a face and a field and a number. It's easy to read about theanine on the internet. It's another thing to sit in the hills of Yame and taste what a man has spent his life concentrating into a cup.

Matcha is where this all becomes most concentrated, because you whisk the whole shade-grown leaf into water and drink everything, rather than steeping and throwing the leaf away. That's the version of this I make. If any of the above makes you curious to feel it for yourself, our matcha is all shade-grown in Japan, and Golden Grade is the one I'd pour you first — the way Kakuda-san poured for me.