A Fonterra spokesperson said the co-operative has seen a strong performance in fresh white milk sales post the Delta-outbreak.
From the four weeks ending September 19, the total Fresh White Milk market in New Zealand grocery increased by 6 per cent in volume.
Lite blue milk holds the second highest share among the total milk market in New Zealand grocery, while trim milk is the third highest.
Further, Fonterra has noticed an increasing trend of consumers opting for bigger pack sizes, with its 3L Anchor BlueTM Milk size one of the fastest growing in the market.
It comes as the return of whole milk has been a hot topic overseas.
An article in New York magazine Grub Street titled "Whole Milk Mounts its Triumphant Comeback: Hot girls are ditching the alternatives and are going back to basics,'" sparked debate around the globe.
In the article, writer Emily Sundberg discussed her time drinking whole milk while traveling Europe, instead of dairy-free alternatives.
The article quoted a down-town waitress named Meetka in New York City. It said ""First, almond milk was too bad for the environment," she theorises. "Now oat milk is much too oily" — allegedly! — "but whole milk stays true to what we were told as children: calcium is good for you."
A Fonterra spokesperson said it is excited to see a shifting perspective on milk consumption overseas.
Thrive Magazine editor and health journalist Niki Bezzant said the latest milk figures from Fonterra isn't surprising.
"I think Kiwis have always been keen on milk, we are big dairy lovers and if you think about milk, it is basically an unprocessed ingredient."
But Bezzant said plant-based milks are having a moment.
"They all have their place. If you are someone who can't have dairy, then plant milk is a really good option because you have a lot more choice and some of them taste pretty good too," she said.
But whether plant-based milk is a food fad remains to be seen.
It reminded Bezzant of when coconut water was once all the rage.
"Does anyone drink coconut water anymore?" she asked.
"Everyone was drinking coconut water and it was a massive growth category around the world and now you hardly ever see it".
But Bezzant said while everyone loves new things, the drive for plant-based milk is driven by sustainability and the environment.
Whether it is whole or plant-based milk, both have their advantages.
"Basically, the big advantage of cow's milk is it is high in protein and high in calcium – those are things we get naturally," Bezzant said.
For plant-based milk, other food sources including calcium need to be added.
"It doesn't mean they are bad, but you just have to be careful because some of them might not have those things added in them."
Bezzant also warns of plant-based milk with added sugar.
At Christchurch's The Caffeine Laboratory, owner James Bagrie has found whole milk has always been the most popular of choices.
He estimates about two-thirds of the milk ordered at his business is blue-top.
But as far as alternative milk goes, he said he's seen a massive rise in oat milk consumption.
"In recent years I think oat milk advancement has been quite rapid.
"I think definitely as far as the alternative milk options goes, oat seems to be the best for the planet and people seem to quite like the taste too," Bagrie said.
That is in comparison with almond, soy and coconut milk – all which his business is ordering less of, he said.