Sixty years to a purple leaf.
TRFK 306/1 is a cultivar of Camellia sinensis developed by the Tea Research Institute of Kenya and grown only in the country's central highlands. The altitude is what produces the anthocyanins. The soil is what produces the GHG. The people are what make it drinkable.
The cultivar.
In the 1960s, an agricultural research station in the central highlands of Kenya began a programme that would take three generations of plant scientists to complete. The Tea Research Institute of Kenya, working at altitudes between 1,800 and 2,200 metres, set out to find — and stabilise — a Camellia sinensis cultivar suited to the Kenyan highland climate, with a phytochemical profile distinct from the catechin-dominant teas of India and Japan.
The work was patient. Selecting a tea cultivar is not breeding in the agricultural sense most people imagine; it is generations of clonal propagation, observation, and re-selection. Plants are tested for hardiness, leaf size, processing behaviour, and — critically for this story — compound expression.
Purple T's leaf is from one of those decades-long selections: TRFK 306/1. The leaf is purple in the field — pale lavender on the underside, deeper plum at the tip. When processed and brewed, the liquor is pale; with a squeeze of citrus, it shifts to rose. The shift is the colour-changing chemistry of anthocyanins responding to a drop in pH. It is, by accident as much as by design, a tea that looks like nothing else.
Altitude, soil, and rain.
The Kenyan central highlands are unusual. They sit on the equator, at altitudes that elsewhere would be subarctic. The combination produces twelve hours of sunlight, year-round, with cool nights, regular rainfall, and volcanic soils rich in the minerals tea cultivars favour.
Camellia sinensis grown above 1,800 metres develops anthocyanins at concentrations not seen at lower altitudes. The plant produces these compounds, in part, as a stress response — protecting itself from the higher ultraviolet radiation that comes with thinner air. What is a stress for the plant is a feature for the cup.
Beyond the climate, there is the soil. The volcanic loam of the Kirinyaga and Nyeri highlands carries the trace minerals — iron, magnesium, potassium — that the cultivar favours. The combination of altitude, soil, and rainfall is what produces the GHG concentration that distinguishes the cultivar's polyphenol profile.
The estate.
Kangaita Factory sits at 1,900 metres above sea level in the Kirinyaga district, on the southern flanks of Mount Kenya. The factory works with a network of around five thousand smallholder farmers across the surrounding region, who grow tea on plots of half an acre to two acres each.
The farmers grow the leaf. The factory processes it into made tea. The relationship is — and has been, for generations — the heart of the Kenyan tea economy.
Purple T's relationship with Kangaita is built on three commitments: a guaranteed premium for smallholders supplying TRFK 306/1, in return for cultivar compliance and quality consistency; specification-linked pricing as phytochemical content becomes measurable at the leaf level; and a multi-year exclusive offtake agreement that gives the factory and the farmers commercial certainty in return for cultivar specialisation.
This is not a charitable arrangement. It is a commercial one structured to put more value into the local economy than a commodity-tea exporter would, because the proposition itself depends on the leaf consistency that long-term farmer commitment produces.
The Tea Research Institute partnership.
The Tea Research Institute of Kenya remains the steward of the TRFK 306/1 cultivar. Its breeding station continues to propagate the cultivar, distribute seedlings to participating farmers, and run the field trials that monitor cultivar performance over time.
Purple T co-funds the Institute's purple cultivar work — propagation, planting expansion, and the supporting agronomic research — as part of the long-term supply chain transformation set out in the strategic plan. The arrangement places scientific custody of the cultivar where it has always been: with the institution that bred it. Commercial use sits with the brand. The two are coordinated, not consolidated.
This separation matters. A consumer brand is not the right home for cultivar science. Cultivar science is not the right home for consumer brand-building. We work in concert; we do not pretend to be each other.
Single origin. Single cultivar. Single cohort.
The phrase that runs across the brand is shorthand for a discipline that affects everything from packaging to pricing to provenance.
Single origin. All the leaf in any Purple T tin comes from one geographic origin: the Kirinyaga highlands of Kenya. Not blended with leaf from elsewhere. The traceability runs from the smallholder plot to the cup.
Single cultivar. Every leaf in every grade is TRFK 306/1. We do not produce a Purple-T blend of different cultivars. The cultivar is the proposition.
Single cohort. Each year's production is a known quantity, in a known window, named with the year. Cohort One is 2026's production. Cohort Two will follow in 2027. The discipline is to release a defined cohort, not a continuous stream — so that customers know what they are drinking and from when it came.