Milk is safe to drink or make into food only when it is milked into clean equipment, cooled below 40°F within 1-2 hours of milking, and pasteurized when you cannot prove every animal is healthy. Pasteurizing means holding the milk at 145°F for 30 minutes, with both numbers required together, and raw milk from an animal that looks healthy can still carry tuberculosis, brucellosis or listeria.
Part of Dairy Production at Scale
Milk handling is the chain of hygiene, cooling and heat treatment between the udder and the table, and every dairy product inherits whatever went wrong in that chain.
Milk Is Perishable And A Disease Carrier At The Same Time
Milk is warm, rich in sugar and protein, and nearly neutral in acidity. Bacteria that land in it multiply within hours, which is why it spoils fast in warm weather. The same properties let disease organisms from the animal, the milker or the bucket ride along. The parent article names three that matter: tuberculosis, brucellosis and listeria. The companion article on Zoonotic Diseases adds that brucellosis is often subclinical in the animal, which means a cow or doe can look perfectly well while her milk is infectious.
Three controls handle almost all of the risk, and they work in this order:
- Keep it clean going in. Washed hands, a cleaned udder, a stripped foremilk and a sanitized bucket keep most contamination out. See Milking Hygiene and Routine.
- Chill it fast. Bacteria that got in grow slowly when cold and quickly when warm, so the target is below 40°F within 1-2 hours. See Rapid Cooling Without Refrigeration.
- Heat-treat it when health is unverified. Pasteurization kills disease organisms that clean handling and cold cannot. See Pasteurization Methods.
What You Need
- A strip cup or dark-bottomed vessel for the first squirts, and a steel bucket (easier to sanitize than wood, per the parent article)
- A clean straining cloth
- A cold water source: a spring house, a stream or a shaded trough
- A thermometer you have checked yourself, because the pasteurization step depends on it
The Decision: Pasteurize Or Not
The parent article allows that a herd known to be healthy, milked hygienically and consumed within 24-48 hours or made into cheese at once has traditionally been used raw. That is a statement about tested herds. After a collapse there is no testing, so the working rule here is stricter: pasteurize everything that leaves the household, and everything given to children, to pregnant women or to anyone ill. For milk distributed to the community, pasteurize without exception.
Common Mistakes
- Trusting a healthy-looking animal. Brucellosis shows as abortion or low milk, or as nothing at all. Look-and-smell is not a test.
- Giving the temperature without the time. 145°F reached for a moment does nothing; the 30-minute hold is the treatment.
- Cooling slowly in a big can. A full 10-gallon can left in the shade stays warm in its core for hours.
- Using milk from an animal being treated for mastitis. See Mastitis; that milk is unsafe whether or not it is pasteurized.
Safety
Raw milk carries disease, and the hazard is in the milk, not the taste
Raw milk can transmit tuberculosis, brucellosis and listeria. Children, pregnant women and anyone with a weak immune system are hit hardest. If you cannot confirm the temperature and time of a heat treatment, bring the milk to a full boil instead, which is above the pasteurization setting; the Boiling article covers the method. Hot milk scalds; never carry an open pot at arm’s length across a crowded kitchen.
What’s Next
- Learn next: Milking Hygiene and Routine — the first and cheapest control
- Combine with: Hygiene & Food Safety — the kitchen side of the same chain