Primary Processing: Preparing Milk
Primary Processing What happens
Skimming milk to remove the The fresh milk is placed in a large tank and cooled-
causing the fat to rise up and is skimmed.
fat (cream) Depending on how much fat is removed, different milks
are produced.
Whole milk (blue top bottle ): contains all fat naturally
produced: 3.9%
Semi-skimmed milk (green top): approximately half :
1.5-2%
Skimmed milk (red top): virtually no fat : 0.5-0.9%
1% fat cow milk is also available (purple top)
Heat treatment of milk Fresh milk is heat treated to kill pathogenic bacteria and
make it safe to drink if stored correctly.
It is homogenised (forcing milk under pressure through tiny
holes which breaks up the fat and prevents from separating
out) during heat treatment to prevent cream from rising to
surface which gives it a consistent texture and flavour.
The milk is treated very quickly in a heat exchanger to a
temperature of 72 C for 15 sec, then cooled rapidly to
below 10 C (usually to 4 C).
Pasteurisation does not significantly affect the flavour
or colour of the milk, and has little effect on the
nutrients.
Pasteurisation
Ultra Heat Treatment The milk is heated in a heat exchanger to 132 C for 1 second,
then cooled and packed inside multi-layered storage packs.
These packs are completely sealed so milk can be stored un-
opened for several months at room temperature (long life
milk).
Once opened, it becomes high risk and must be stored in a
refrigerator to consume within a few days.
This has minimal effect on flavour of milk or nutrients.
However after 6 months in storage, up to 60% of vitamin B12
can be lost.
Primary Processing What happens
Skimming milk to remove the The fresh milk is placed in a large tank and cooled-
causing the fat to rise up and is skimmed.
fat (cream) Depending on how much fat is removed, different milks
are produced.
Whole milk (blue top bottle ): contains all fat naturally
produced: 3.9%
Semi-skimmed milk (green top): approximately half :
1.5-2%
Skimmed milk (red top): virtually no fat : 0.5-0.9%
1% fat cow milk is also available (purple top)
Heat treatment of milk Fresh milk is heat treated to kill pathogenic bacteria and
make it safe to drink if stored correctly.
It is homogenised (forcing milk under pressure through tiny
holes which breaks up the fat and prevents from separating
out) during heat treatment to prevent cream from rising to
surface which gives it a consistent texture and flavour.
The milk is treated very quickly in a heat exchanger to a
temperature of 72 C for 15 sec, then cooled rapidly to
below 10 C (usually to 4 C).
Pasteurisation does not significantly affect the flavour
or colour of the milk, and has little effect on the
nutrients.
Pasteurisation
Ultra Heat Treatment The milk is heated in a heat exchanger to 132 C for 1 second,
then cooled and packed inside multi-layered storage packs.
These packs are completely sealed so milk can be stored un-
opened for several months at room temperature (long life
milk).
Once opened, it becomes high risk and must be stored in a
refrigerator to consume within a few days.
This has minimal effect on flavour of milk or nutrients.
However after 6 months in storage, up to 60% of vitamin B12
can be lost.
