CLAIM:
Packaged milk (pasteurised) does not need to be boiled, and can be safely heated only till lukewarm and used directly for making tea and coffee.
FACT:
Packaged milk is already pasteurised, which kills harmful bacteria and makes additional boiling generally unnecessary. Experts explain that overheating or prolonged boiling can reduce its nutritional quality, particularly B-complex vitamins and proteins. For safety and taste, it is sufficient to heat pasteurised milk to lukewarm, and it should always be properly refrigerated and handled under hygienic conditions.
It is almost a fixed household routine in Indian homes. Milk comes in the morning, the packet is washed, cut open, and immediately poured into a vessel to be boiled. From making chai to giving children their daily glass of milk, boiling packaged milk is treated as a non-negotiable safety step. But have you ever stopped to wonder if this daily habit is even necessary?
In a viral Instagram reel, Dr Manan Vora, an orthopaedic surgeon, challenges this long-held belief. In the reel, he explains that “it is not at all necessary to boil the milk that comes in the packet.” He adds that packaged milk available today is already pasteurised and processed at very high temperatures, where harmful bacteria are destroyed, making additional boiling at home unnecessary from a safety point of view. “We have just been used to boiling it because that was the rule in our homes,” he says, adding that overheating can even affect taste and nutrition. “Heat it up to normal lukewarm, and it is ready to use in tea and coffee. That’s it,” he adds.
Understanding the pasteurisation method
Pasteurisation is a heat-treatment process used to make milk safe for consumption by killing harmful bacteria naturally present in raw milk. During this process, chilled raw milk is rapidly heated to a specific temperature for a fixed duration and then quickly cooled. In most standard milk processing plants, the milk is heated to about 72°C and held at that temperature for at least 15 seconds before being immediately cooled back to around 4°C. This controlled heating is sufficient to destroy disease-causing microorganisms while preserving the milk’s nutritional quality and taste.
An important part of modern pasteurisation is its energy-efficient design. The dairy industry often uses the heat from freshly pasteurised milk to warm the next batch of cold raw milk. At the same time, the incoming cold milk helps cool the heated pasteurised milk. This heat-exchange system reduces the need for extra heating and refrigeration, making the entire process more efficient and sustainable.
The most widely used method of pasteurisation today is High Temperature Short Time (HTST) pasteurisation. It involves heating milk to at least 72°C for not less than 15 seconds, followed by rapid cooling. A similar method, Higher Heat Shorter Time (HHST) pasteurisation, uses slightly higher temperatures for an even shorter duration. For milk to be labelled Ultra Pasteurised (UP), it must be heated to a minimum of 138°C for at least two seconds. This process extends the milk’s shelf life, though refrigeration is still required.
Another advanced method is Ultra High Temperature (UHT) processing, also known as aseptic processing. In this method, milk is heated at extremely high temperatures using sterile equipment and is filled into completely sealed, sterile packaging. UHT milk becomes shelf-stable and does not require refrigeration until the package is opened. The exact time and temperature for aseptic processing are validated by a designated Process Authority under regulatory supervision.
Do we really need to boil packaged milk?
Many people believe that boiling milk is necessary to kill bacteria and prevent foodborne illness. However, when it comes to packaged, pasteurised milk, this additional step is generally not required for safety. In countries like the United States, all commercially produced milk sold across state lines must be pasteurised. Pasteurisation does not mean boiling, but heating milk to a temperature high enough to destroy harmful pathogens. The standard process heats milk to about 72°C for 15 seconds, followed by rapid cooling, which is sufficient to make it microbiologically safe.
Boiling becomes necessary only in the case of ‘raw, unpasteurised milk’. When raw milk is heated to near-boiling temperatures, bacterial levels reduce significantly, lowering the risk of infection. Without this heat treatment, raw milk can carry dangerous pathogens that may cause serious illness.
According to the Centers for Disease Control and Prevention, raw milk can harbour harmful bacteria and pose serious health risks. Both the Food and Drug Administration and the CDC strongly recommend consuming only pasteurised milk. This advice is also backed by major medical bodies such as the American Medical Association and the American Academy of Paediatrics.
According to the FDA, research has shown no meaningful difference between the nutritional content of pasteurised and raw milk, despite claims to the contrary.
“Numerous studies have indicated that pasteurisation has minimal impact on milk nutritional quality,” according to the US federal agency.
What experts recommend
Rajeshwari Panda, Head of the Dietetics Department at Medicover Hospital, Kharghar, Navi Mumbai, explained that the process of pasteurisation itself involves pre-heating the milk, making additional boiling generally unnecessary. “There is no purpose in boiling pasteurised milk under normal conditions,” she said. However, she added that in certain circumstances, such as if the packet has been opened or not properly refrigerated, boiling can help ensure the milk has not spoiled.
On the issue of milk spoiling during storage, Panda said, “After pasteurisation, milk still needs to be stored properly in a cool environment. If it is left at room temperature, especially in summer, it can spoil. Boiling does not prevent spoilage; refrigeration is the key to keeping milk safe for longer periods.”
She also highlighted the effect of overheating on nutritional quality. “Any additional processing, like prolonged boiling, can lead to some nutrient loss, mostly B-complex vitamins and proteins. Pasteurised milk only needs slight preheating, just enough to reach lukewarm temperatures or to change the texture slightly,” Panda explained.
Regarding consumption for people with specific health concerns, she said, “Even individuals with critical health conditions can safely consume pasteurised tetra-pack milk without boiling. But if the milk has been opened or left at room temperature for a long time, it may have spoiled. In such cases, boiling can help ensure it is safe.”
She added that alternative milk products like almond milk, which come in tetra packs, also do not require boiling. “For packed milk that has already been pasteurised, additional boiling is not needed. Only fresh milk from local vendors or ‘tabela’ (stable) milk should be boiled before consumption,” she said.
On proper storage, Panda emphasised, “In Indian temperatures, refrigeration is the best way to store milk to maintain its safety and quality.”
This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS.