With Australia's alternative milk industry on the rise, one New South Wales farmer is considering a dairy substitute that is not even legal yet.

Stuart Larssons, a soybean grower at Mallanganee in northern New South Wales, wants to produce hemp milk.

"If you've tasted hemp milk it's a lovely mild product to drink, high in omega sixes and threes, all the good things in there," Mr Larssons said.

Hemp is a species of cannabis although, unlike marijuana, it has low levels of the mind-altering chemical compound tetrahydrocannabinol (THC).

Hemp milk is made by crushing the seeds and mixing them with water.

The milk is already sold overseas, although it cannot be sold legally as a food product in Australia yet.

Stuart Larssons says hemp milk has a "lovely mild" taste. ( Landline )

In 2015 food and health ministers in Australia and New Zealand rejected an application by Food Standards Australia New Zealand (FSANZ) to permit the sale of foods made from low-THC hemp seeds.

Authorities were worried about the impact eating or drinking hemp products may have on roadside drug testing.

They also thought legalising hemp seed products would send a confusing message about the safety of its controversial cousin, cannabis.

Commonwealth, state, territory and New Zealand food ministers have asked FSANZ to address these information gaps, and then work on a proposal that would reconsider low-THC hemp being legally designated as a food.

If they do, Mr Larssons, who made a name for himself in the soy milk market, is keen to replicate that success in the hemp milk market.

"It's like anything new, it has got to be tested and proven there's nothing wrong with the product, so we've just got to wait for what the food authorities say," he said.

Plant-based milks growing in popularity

NSW farmer Mason Roy believes the US macadamia market will be profitable. ( ABC News )

IBISWorld analyst Lauren Magner said the popularity of plant-based milks, such as almond, soy and macadamia, had been on the rise over the past five years.

It is a trend that has mirrored the United States, and farmers like Mason Roy are looking to capitalise.

While many macadamia farmers are expanding to meet a growing demand for nuts in China, Mr Roy believes the US is an even better market.

"Cow's milk is on the down in the US and the same with some alternatives like soy, which is on the way down," he said.

"We've seen almond milk grow a lot and we think nut milk there has got a great potential there to explode."

Last year Mr Roy and his family launched "Milkadamia", which sells for up to $6 in America, and about $8 in Australia.

"It was formulated to work well with coffee to be able to get the creamy full mouth feel, and now we've moved on to a Milkadamia original and an unsweetened, which is for pure drinking and cereals," he said.