Hygiene and raw material control
As milk is a low acid food that is very susceptible to spoilage and transfer of pathogenic bacteria
to consumers, the methods used to handle milk at the dairy play an important role in
determining the quality of the final product. The main hygienic requirements are:
Thoroughly clean and sterilize (with chlorine solution or boiling water) all equipment and
utensils before and after processing (NB aluminium equipment should not be cleaned
with chlorine solution).
Strict enforcement of personal hygiene measures.
Filter milk after milking to remove visible dirt and any 'ropiness'.
Cool milk immediately to control further growth of micro-organisms and enzyme activity
The main control points are the temperature and time involved in heating and cooling the milk.
Overheating and slow cooling causes changes to flavour, colour and nutritional value;
underheating may result in inadequate destruction of enzymes and micro-organisms leading to a
reduced shelf life and the risk of food poisoning.
Packaging and storage
During packaging the most important quality control check is to ensure that filling equipment,
bottles and caps are thoroughly cleaned and sterilized to prevent recontamination of the heat
treated milk. This is especially important if the bottles are reused. Bottle fill weights should be
accurately controlled and storage temperatures should be controlled below 10°C.
Bottle sterilising equipment
References and further reading
Dairy Processing Practical Action Technical Brief
Basic Rules of Hygiene, Sanitation and Safety in Food Processing Practical Action
Yoghurt Incubator Practical Action Technical Brief
Soured Milk and Yoghurt Practical Action Technical Brief
The technology of traditional milk products in developing countries, Technical Bulletin
#85, Food and Agriculture Organization of the United Nations, Rome, 1990
Butter and Ghee, Practical Action Technical Brief.
Cheese making, Practical Action Technical Brief.
How to HACCP. Dillon, M and Griffith, C., M.D.Associates, Cleethorpes Enterprise
Centre, Unit 43, Jackson Place, Humberston, Grimsby, South Humberside DN 36 4AS
Opportunities in Dairy Processing, Fellows, P.J. and Axtell, B.L.A., (Eds.), CTA, 2008.
Appropriate Food Packaging: Materials and methods for small businesses Fellows, P.,
Axtell, B., Practical Action Publishing, 1993.
Traditional Foods: Processing for profit Fellows, P.J., (Ed.), Practical Action
Dairy Processing UNIFEM Practical Action Publishing, 1996.
Dairy Processing Handbook, Alfa Laval/Tetra Pak Processing Systems, S-221 86,
Lund, Sweden, 1995.
Dairy Science and Technology Education, Goff, D., University of Guelph, Canada,