Milk Shelf Life

It's quite often that you leave a bowl of milk in the morning, oblivious that it might get spoiled the next day. The next morning you observe the color changed to off white and the milk emitting a stale and fowl odor. You have no other option other than discarding the milk and replacing it with a fresh pack. This is a very common thing that happens almost in every house. The reason is, you might not be aware of the shelf life of milk, the optimal temperature at which it should be kept and the time period for holding the quality.

Shelf Life of Milk

There's a standard followed by the milk industries to determine the shelf life of milk. When raw milk is transferred to milk processing plants, it undergoes various industrial processes to increase the shelf life of milk. The raw milk contains some bacteria that needs to be reduced. Bacterial crowd in milk is reduced by a process known as pasteurization. This increases the shelf life of milk and gives milk a refrigerated shelf life. When milk is pasteurized under High Temperature Short Time (HTST), then milk has a shelf life of 2-3 weeks. Ultra high pasteurized milk has longer shelf life extending from 2-3 months. Further increasing milk shelf life, involves a technology where combination of ultra heat treatment (UHT) with sterile handling and container techniques are carried out. This highly aseptic packaging increases the shelf life of milk to 3 - 4 months.

The other method for increasing the shelf life is, use of high hydrostatic pressure processing (HPP) techniques. It involves subjecting milk under high pressure that kills bacteria and thus accounting to use of milk for an extended period of time. With this process, milk can be stored in refrigeration for at least 45 days.

The shelf life of milk is determined by the amount of bacteria contained in the raw milk. Since, pasteurization eliminates bacterial load, the shelf life of milk also increases as compared to raw or conventional milk. Milk shelf life is also dependent on the equipment, formulation techniques and methods of packaging.

Conditions for Storing Milk

Milk forms a very good growth media for multiple varieties of micro-organisms. If you are consuming raw milk, always boil it at 100ºC or above. This kills bacteria and also increases the shelf life of milk. Store in a refrigerator and use it for maximum 4 days, if it's raw or conventional milk variety. Storing milk at 45º F to 55º F increases its shelf life. Pasteurized milk when left open and exposed to air for long time gets damaged. While consuming pasteurized milk, make sure that you always keep it under refrigeration for allowing it to last for 3 - 4 months. Normally, under optimum conditions and 40º F, pasteurized milk lasts for14-16 days. Organic milk is not only good for health, but also has a good shelf life. Dry milk products must always be stored in a cool place. They are very sensitive to environmental conditions, like moisture and temperature. Dry milk contains vitamin A and vitamin D that are photosensitive and degrade when exposed to light. Air conditioning or refrigerating dry milk can give an extended nutrient shelf life.

Before buying a packet of milk, check the manufacturing and expiry date. For getting maximum shelf life, follow the instructions written on the pack.