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SL28

Selected at Scott Laboratories in Kenya in the 1930s. Drought-tolerant, low-yielding, and responsible for the blackcurrant acidity Kenya is famous for.

SL28 was selected in the 1930s by Scott Agricultural Laboratories in Kenya, from material with Bourbon lineage, and it is one of the most successful quality selections ever made.

What it was selected for

Drought tolerance, primarily — Kenya needed varieties that could survive dry periods. Cup quality was a secondary criterion that turned out to be the enduring one.

The profile

SL28 is responsible for the acidity Kenya is famous for: blackcurrant, grapefruit, tomato, with a juicy, mouth-watering quality and a syrupy body underneath.

It is intense and immediately recognisable, and it is the reason people who love Kenyan coffee love it specifically.

Grown elsewhere

SL28 has been planted in Colombia, Panama, Ecuador and elsewhere, usually with encouraging but less dramatic results. It keeps some character and rarely reaches Kenyan intensity.

That suggests the variety is necessary but not sufficient — Kenya’s volcanic soil, unusually high in phosphoric acid, and its distinctive double-fermentation washing process are doing part of the work.

Drawbacks

Low yield and high susceptibility to coffee leaf rust and coffee berry disease. Kenya has bred resistant alternatives — Ruiru 11 and Batian — which yield better and are widely accepted as cupping less distinctively.

Many Kenyan lots now mix SL28, SL34, Ruiru 11 and Batian, and bags specifying SL28 and SL34 command a premium.

Brewing it

Filter, light roast, a clean brewer that shows acidity. Grind fine and brew hot — these are dense beans and under-extraction makes the acidity sour rather than bright, which is the commonest mistake with Kenyan coffee.

Questions people actually ask

Is SL28 the reason Kenyan coffee tastes of blackcurrant?

It is the largest single factor, alongside volcanic soil high in phosphoric acid and Kenya’s distinctive double-fermentation washing. Grown elsewhere, SL28 keeps some of the character but rarely reaches Kenyan intensity.

What is SL34?

A sibling selection from the same programme, Typica-related rather than Bourbon-related. It tolerates rain better and is usually described as slightly less intense. Kenyan lots often contain both.

What you need to make it

The equipment this actually requires — not a shopping list, the shortest route to doing it properly.

  • The reference pour-over Manual brewers

    Hario V60 02 Ceramic

    60° cone · spiral ribs · 1–4 cups

    The most transparent cup you can brew for twenty euros, and the least forgiving. Ceramic holds heat where plastic does not — and the open bottom means your pour, not the dripper, decides the coffee.

    Best for: Someone who wants to taste what a single-origin coffee is actually doing.

    8.2/10

    ≈ $25 / £20 / 22 €

  • Best filter grinder Grinders

    Fellow Ode Brew Grinder Gen 2

    64 mm flat burr · filter only · single dose

    64 mm flat burrs, near-zero retention and a footprint the size of a mug, built for filter and honest about not doing espresso. For pour-over it is the clearest grind you can buy at this price.

    Best for: V60, Chemex, AeroPress and batch brewing, where clarity is the whole point.

    8.7/10

    ≈ $345 / £275 / 300 €

  • Best pour control Kettles

    Fellow Stagg EKG Pro

    0.9 L · ±1 °C hold · counterbalanced gooseneck

    The best-pouring kettle sold, and the hold function matters more than the thermometer. Expensive for boiling water — but if you brew pour-over daily, it is the accessory that most improves the cup.

    Best for: Daily pour-over, where flow rate is the variable you are trying to control.

    8.6/10

    ≈ $195 / £165 / 180 €