Butter and ghee
Practical Action
Hygiene
Technical Brief: Dairy processing - an overview gives details of hygiene and sanitation, the
methods needed to ensure that good quality milk is used, the design of a dairy and the use of
correct cleaning procedures. Hygiene requirements are also described in Technical Brief:
Hygiene and safety rules in food processing.
Avoiding spoilage
The main cause of spoilage of butter and ghee is rancidity, and this is prevented by packaging
and storage control (below). Unclean equipment, contaminated milk, poor hygiene by production
staff, and incorrect processing and storage conditions will each also cause spoilage. All
equipment should be thoroughly cleaned after use and checked before production starts again.
The temperature and time of heating the cream should be monitored and controlled to ensure
that it is not over- or under-heated. For lactic butter, the temperature and time of incubation
should be monitored and controlled to ensure that the fermentation takes place correctly.
Raw material control
The milk used for butter and ghee production should be fresh, good quality and free from dirt
and excessive contamination by bacteria, so that it will not clot or curdle during processing.
Older milk can impart an unpleasant flavour to the final product. The fat content of cream can
be tested using the ‘Gerber’ method with a ‘cream buytrometer’. However, the cost of analytical
equipment and the expertise required to do the test are likely to be greater than small-scale
butter makers can afford. If a producer wishes to know the fat content of cream, the test can be
done at a Bureau of Standards or a university Food Science Department.
Process control
A process control schedule should be prepared for each product. Table 3 is an example of a
process control schedule for fresh butter production. If a refrigerator or chilled water is not
available, it is possible to make butter but there may be the following problems:
If the cream is not allowed to age at a low temperature, the milk fat does not develop the
crystalline structure needed for good separation into butter and buttermilk.
A higher temperature during churning reduces the butter yield, because some of the
butterfat liquefies, and is lost with the buttermilk.
The water used for washing butter should be cold to prevent it melting the butter. It must
also be of drinking quality or else it will contaminate the butter and reduce its shelf life. Any
food poisoning bacteria in the water will be transferred to the butter (although they are
killed if salt is added to the butter).
The shelf life of butter is reduced if it is stored without refrigeration. At refrigeration
temperatures, butter will keep for many months, but at ambient tropical temperatures
rancid odours may develop after a few days. However, in many countries, a slightly rancid
flavour in butter is acceptable. In some countries an anti-oxidant such as BHA or BHT2 may
be permitted by law to prevent rancidity. However, butter is not usually stored for long
periods and these chemicals may not be readily available, may be expensive, and are not
needed.
Stage in process
Pre-heating/
milk separation
Activity
Warm milk before passing through
a cream separator
Process control points
Check the temperature is at 36-
40°C during pre-heating to
optimize the efficiency of the
separator. If the milk is too hot,
the milk fat will be difficult to
separate and the yield of cream
will be reduced.
2 Butylated Hydroxy Anisole and Butylated Hydroxy Toluene
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