Why Milk Spoils and How Dairy Farmers and Shops Can Prevent It
- Bacteria in warm milk make it sour
- Cool to about 4 °C soon after milking
- Dirty equipment is the main source of bacteria
- Never mix warm and cold milk
On this page
The Main Causes
| Cause | Fix |
|---|---|
| Milk left warm for hours | Cool quickly in a chiller |
| Dirty cans, buckets and machines | Wash, sanitise and dry after every use |
| Poor udder and hand hygiene | Clean udders and hands before milking |
| Mixing evening and morning milk warm | Cool each batch before mixing |
| Plastic jerrycans | Use stainless steel cans |
| Sick cows (mastitis) | Keep milk from treated cows out, as the vet advises |
Keep It Cold
Cold slows bacteria. Collection centres and shops cool milk to about 4 °C. See what size milk chiller.
100 LTRS MILK CHILLERKSh 280,000
300 LTRS MILK CHILLERKSh 330,000
H-TECH 500 LITERS MILK CHILLERKSh 450,000
H-TECH 1000 LTRS MILK CHILLERKSh 800,000| Product | Price |
|---|---|
| 100 LTRS MILK CHILLER | KSh 280,000 |
| 300 LTRS MILK CHILLER | KSh 330,000 |
| H-TECH 500 LITERS MILK CHILLER | KSh 450,000 |
| H-TECH 1000 LTRS MILK CHILLER | KSh 800,000 |
Current listed prices incl. VAT (updated 5 October 2026).
Keep It Clean
Follow a strict washing routine for cans, buckets, milking machines and chillers: chiller cleaning and milk cans and handling.
| Product | Price |
|---|---|
| 20l milk storage can | KSh 8,500 |
| 50l milk storage can | KSh 15,000 |
| 100l milk storage can | KSh 24,000 |
| Lactometer | KSh 500 |
Current listed prices incl. VAT (updated 5 October 2026).
Test on Arrival
Collection centres test milk with simple checks such as the lactometer and freshness tests: how to test milk.
Heat Treatment
For processing and selling, pasteurisation kills harmful bacteria: how pasteurisation works. Dairy handling is regulated by the Kenya Dairy Board.
Watch: Milk chillers and pasteurizers
Frequently asked questions
Why does my milk go sour quickly?
Usually it stays warm too long, or equipment is not clean enough, so bacteria multiply.
At what temperature should milk be kept?
Cool to about 4 °C soon after milking and keep it cold.
Can sour milk be sold?
Sour raw milk is rejected by buyers; fermented products like mala are made deliberately with cultures.
Do plastic containers make milk spoil faster?
Scratched plastic is hard to clean and can hold bacteria; stainless cans are better.