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Mursik Yoghurt
ShareKalenjin soured milk made the traditional way but fermented under control — boiled milk, a defined starter, food-grade vessels, a short cold ferment. Smoky, thick and properly tangy, without the guesswork. Read more
Everything about this milk
Where it comes from, how we make it, what it gives you — and what the research says.
Three hundred years old
Mursik is the traditional fermented milk of the Kalenjin communities of the Rift Valley — Kipsigis, Nandi, Tugen, Marakwet, Pokot. It began as a way of keeping surplus milk through the dry season, not as a delicacy.
Traditionally it ferments in a hollowed calabash gourd, a sotet , lined with fine charcoal from African senna or wild olive. The charcoal seals the porous shell, slows spoilage and gives the milk its smoky flavour and grey tint. It sours on its own for three to five days.
It carries weight beyond the kitchen: served to seal agreements, and offered to returning Kenyan athletes from the gourd.
Traditional taste, controlled process
VERIFY Confirm every step with the producer before publishing.
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Milk
Whole milk from one highland dairy, collected the same morning and boiled.
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Vessel
Sanitised food-grade steel, not a charcoal-lined gourd — a gourd can’t be sterilised reliably.
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Culture
A defined lactic acid bacteria starter rather than spontaneous fermentation.
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Ferment
About 24 hours under temperature control, not three to five days at ambient. The single biggest safety difference.
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Smoke
A controlled infusion of the same traditional woods — flavour without charcoal residue.
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Chill
Straight into the cold chain and to your door.
Per 100ml
| Energy | 61 kcal |
|---|---|
| Protein | 3.5 g |
| Fat | 3.3 g |
| Carbohydrate | 4.7 g |
| Added sugar | 0 g |
| Calcium | 120 mg |
| Live cultures | Yes |
- Protein — complete, at a low cost per gram.
- Calcium — a 250ml cup covers a useful share of an adult’s day.
- Live cultures — fermentation leaves them in the finished milk.
- Less lactose than fresh milk, though not lactose-free.
- No added sugar , unlike most flavoured yoghurt.
What the evidence supports
- Nutrient-dense, affordable protein and calcium.
- Fermentation lowers lactose, helping some people tolerate it.
- Lactic acid bacteria from mursik show probiotic potential in lab testing.
- Fermented dairy generally does well in the gut-health literature.
- That it improves athletic performance. Altitude, training culture and running from childhood explain the Kalenjin record far better.
- That it treats or prevents any illness.
- That its probiotic content matches a commercial product — strains and counts vary batch to batch.
What the studies found
- Acetaldehyde. A 2013 study fermented milk with eight starter cultures from Kalenjin families. Seven produced acetaldehyde above the mutagenic threshold; four exceeded it tenfold. Levels peaked near 48 hours — inside a traditional ferment.
- Disease association. A 2025 case-control study in Nandi County found the odds of oesophageal carcinoma roughly nine times higher in frequent consumers and three times higher in infrequent ones, after adjusting for alcohol, tobacco, age and cooking fuel.
- Mould toxins. A gourd can’t be sterilised; mursik samples have carried mycotoxins including aflatoxin.
- Charcoal. A plausible source of polycyclic aromatic hydrocarbons.
What it doesn’t mean
The 2025 study was small — 32 cases, hospital-recruited controls — and observational, so it shows association rather than cause. Fermented dairy elsewhere shows neutral or protective associations. The hazard most likely sits in this fermentation process — long ambient ferments, unsterilisable vessels, charcoal — rather than in soured milk itself. The researchers called for safe alternatives for fermenting milk. That is what this product is meant to be.
Who should be careful
- Anyone with a history of oesophageal disease, or persistent pain or difficulty swallowing, should talk to a doctor first.
- Pregnant people, infants under 12 months, older adults and anyone immunocompromised: pasteurised milk only, kept chilled.
- Lactose intolerance: start small. Lower lactose is not no lactose.
- Don’t drink it hot — beverages above about 65°C are themselves a risk factor.
Nieminen et al., Cancer Epidemiology, Biomarkers & Prevention , 2013 · Mutai & Mweu, PLOS One , 2025 · Kigen et al., Infectious Agents and Cancer , 2017 · Talaam et al., 2018. General information, not medical advice.
Keep it cold
- Refrigerate at 4°C or below from delivery.
- Best within 14 days. Date printed on the cap. VERIFY
- Once opened, use within 5 days, cap sealed.
- Shake before pouring — separation is normal, not spoilage.
- Don’t leave it out. Warm fermentation is what we designed out.
- Yeasty or alcoholic rather than clean and sour? Don’t drink it. Tell us and we’ll replace it.
One dairy, one herd
Every batch traces to a single producer. VERIFY — name, location, herd size, collection routine and certifications go here.
| Producer | — |
|---|---|
| Location | Kericho County |
| Milk source | Single herd |
| Batch code | On cap |
Chilled, to your door
- Chilled delivery within Nairobi. Order before 4pm for next-day. VERIFY
- Fermented after you order — we don’t hold stock and stretch its life.
- Warm, damaged or off on arrival? Replaced or refunded. Keep the container.
✵ Goes well with