Sydney company Made by Cow has obtained the approval of the NSW Food Authority to use cold pressure as an alternative to conventional heat pasteurisation and sell "cold-pressed raw milk".

Company founder Saxon Joye says the product – sourced from a single, carefully managed jersey herd and available from Harris Farm Markets in Bowral – was still raw and retained the nutrients usually affected by heat.

"Good herd management, hygienic milking techniques and the cold pressure method have meant we can put 100 per cent safe, raw milk onto supermarket shelves," said Mr Joye.

"The bottles of milk are placed under enormous water pressure, squashed in about 15 per cent, to remove the harmful micro-organisms."

Selling raw milk for human consumption is illegal in Australia because it contains micro-organisms that can increase the risk of contracting serious illnesses.

A child died in 2014 after drinking raw cow's milk, triggering the Victorian government to introduce a law compelling raw milk producers to add a bitter, gag-inducing agent.

While the product is labelled "cold-pressed raw milk", the NSW Food Authority says it doesn't recognise it as raw milk because it has undergone "high pressure processing" to eliminate pathogens.

It worked with Made by Cow for more than a year to ensure the product was safe and suitable for human consumption.

"Any claims that may be perceived as promoting raw milk consumption would be investigated as the NSW government has taken a very firm stance against the sale of unpasteurised milk for human consumption," the Food Authority's spokeswoman said.

Raw milk advocates have attempted to flout the law by buying and selling raw milk as "bath milk" for cosmetic purposes.

They believe raw milk is a safe, healthier drink because pasteurisation, which involves heating milk to 72C for 15 seconds, "destroys many anti-microbial and immune-enhancing components".

Professor Peter Collignon, a leading infectious disease physician and microbiologist, said he was concerned about the lack of research showing the efficacy of cold pressure.

"I do worry this is a marketing exercise for raw milk but without the science to show the process is anywhere near as good as pasteurisation," he said.

"The [data and research] that shows [cold-pressure is just as good as pasteurisation] needs to be robust and available for all to see, including the public, and needs independent verification."

The Food Authority's spokeswoman did not directly answer questions about releasing data to support its decision to approve the new method.

The "cold-pressed raw milk" will appear on shelves at Harris Farm Market stores and About Life health shops in 750ml bottles at $5 each on Thursday.

The authority confirmed it has discussed the product with its counterparts in other states and its approval meant the product could be sold nationally.

Nutritionist and dietitian Lyndi Cohen has analysed the milk's nutritional profile and said the product had higher protein, calcium, energy and fat content than regular cow's milk.

She believes the "wholesome" product delivers on its "raw milk" claim.

"It's cold-pressed and it's raw, because it hasn't been cooked, it hasn't been heated," she said.

"The heating process kills the enzymes and changes the structure of key nutrients that are heat sensitive."

​Tristan Harris, co-chief executive of Harris Farms, which has 24 stores in NSW, believes "cold-pressed raw milk" will generate excitement.

"I think word will spread quickly and you're not going to have the potential dangers with unpasteurised milk," he said.

"I hope at some point, as volumes go up, the price will come down."

Cold pressure is usually applied to foods such as meat and juices to remove bacteria.