Assessing Your Milk Cooling Performance

Assessing Your Milk Cooling Performance

1 July 2018

The new Ministry for Primary Industries milk cooling standards that came into effect on 1 June 2018 state that milk must:

  • be cooled to 10ºC or below within four hours of the commencement of milking; and
  • be cooled to 6ºC or below within either:
    1. six hours of the commencement of milking, or
    2. two hours from the completion of milking, whichever is the soonest; and
  • be held at or below 6ºC without freezing until collection or the next milking; and
  • not exceed 10ºC during subsequent milkings

Where there is continuous or extended milking, such as automated milking systems, the milk must enter the bulk milk tank at 6°C or below. (Continuous milking is defined as milking for six hours or longer from the time that milk first enters any bulk milk tanks).

Milking time duration - hours Milk Temperature at completion of milking Time you have after the completion of milking to reach 6°C
Time - Hours Temp - °C
1.0 to 4 N/A 2.0 6
4 10 2.0 6
4.5 9 1.5 6
5 8 1 6
5.5 7 0.5 6
6 6 0 6

Assess Your Current Milk Cooling Performance

We recommend you use this checklist to assess whether your farm cooling system is likely to meet the proposed new cooling regulations. By completing this assessment you are taking a snapshot of your cooling performance, which only provides an indication of current temperature. It does not necessarily mean you will meet the standards for 365 days of the year.

Y/N Temperature at time of assessment
If you milk for less than 4 hours
Is the milk temperature two hours after milking less than 6°C?
Does the milk temperature stay below 10°C during the next milking? (Measure this by taking a temperature reading at the completion of the second milking into the vat)
If you milk for 4-6 hours
Is the milk temperature less than 10°C four hours into milking?
Is the milk temperature less than 6°C six hours from the beginning of milking?
Does the milk temperature stay below 10°C during the next milking?
If you milk for 6+ hours
Does the milk enter the vat at less than 6°C?

  • If you remove milk from the milking system to determine its temperature, do not return it to the vat.
  • Use an accurate temperature gauge suitable for use in the farm dairy (i.e. no glass thermometers).

If you answer No to any of the questions that apply to your situation, contact your refrigeration specialist to review your vat refrigeration and discuss changes needed to meet the new standards.

Farm Source have partnered with Tru-Test, Snapchill and Varicool to offer exclusive deals on milk cooling systems to Fonterra farmers with the goal of reducing costs to meet the new milk temperature standards. To find out more, talk to your local Farm Source Team or visit

Our aim is for Farm Source to provide the best service possible to our customers. We would greatly appreciate your feedback as to how we're going and how we can improve.