FPD is used as an indicator of extraneous water content which may have been added to milk and can be an issue on dairy farms.
If milk is tested to be below the thresholds, it could be rejected or penalised.
It is a required quality standard for milk.
Factors impacting the freezing point
FDP in milk can be an issue on dairy farms, most commonly in spring and summer.
Main factors impacting the freezing point include:
- climate
- stage of lactation
- seasonality
- breed, and
- ruman protein balance.
However, the addition of water into milk is the most significant factor affecting the freezing point of milk.
New Limits
In 2001, new interpretation limits were set following a detailed analysis of freezing point data which found that over the period 2006-2020, the average FPD in Great Britain fell.
Based on the most recent data, the accept/reject threshold for milk should now be set at 505 m°C (rather than 509 m°C) for tanker and retail milk, which will limit tanker rejections.
Find out more about the research and change in limit thresholds: Dairy Transport Assurance Scheme | Interpretation of freezing point depression in milk (PDF)
Advice
If the FDP of your milk has dropped and you are unsure why you should check for any possibility of water contamination of milk.
For more information, visit: AHDB | Freezing point depression
