"Would you like a vegan wine with your steak?"

It's not as silly a question as it sounds.

Australian winemakers who once hid the fact their wines were vegan-friendly are now proudly displaying their credentials on bottle labels because in today's market, being a more naturally made product is something to advertise.

But wine is just grapes, right? Not exactly.

Conventional wines often use animal products during processing, specifically, proteins such as milk, egg whites and isinglass — made from the float bladder of the sturgeon fish.

They are known as fining agents and, while they don't remain in the finished product, they are often the reason wine is not cloudy or bitter.

Harvesting grapes at Kalleske vineyard in the Barossa Valley. ( ABC News: Dominique Schwartz )

Tony Kalleske and winemaker brother Troy Kalleske (pictured right) look over the morning's harvest. ( ABC News: Dominique Schwartz )

South Australian winemaker Troy Kalleske has been making vegan wine for 16 years, but it's only now that he uses it as a "selling point".

"[Back then] organic wine was not of the best quality, it was very fringe, and the perception was that it was inferior, so we didn't want to be categorised," he said.

"We wanted to make sure people bought our wine for quality."

Partial to any of these varieties? Vegan wine: Produced without any animal products. That means winemakers do not use conventional fining agents such as egg whites, milk or a protein found in fish float bladders.

Produced without any animal products. That means winemakers do not use conventional fining agents such as egg whites, milk or a protein found in fish float bladders. Organic wine: Made from grapes and by processes free from synthetic pesticides, herbicides, hormones and antibiotics. Crops must be non-GMO and processes must be water-efficient and biodiversity-friendly, according to Australian Organic.

Made from grapes and by processes free from synthetic pesticides, herbicides, hormones and antibiotics. Crops must be non-GMO and processes must be water-efficient and biodiversity-friendly, according to Australian Organic. Biodynamic wine: Based on the biodynamic and holistic practices developed by Austrian philosopher Rudolph Steiner in the 1920s. Considered to take organic practices a step further, focusing on regenerating the soil to be fully sustainable and farming by the astrological calendar.

Based on the biodynamic and holistic practices developed by Austrian philosopher Rudolph Steiner in the 1920s. Considered to take organic practices a step further, focusing on regenerating the soil to be fully sustainable and farming by the astrological calendar. Natural wine: Produced with as little intervention from chemicals or technology as possible, both in the growing of the grape and the winemaking process. Often cloudy and unrefined. Could still contain sulphites but they would be a natural by-product of the fermentation process.

All of the 18 estate wines produced by his family's Barossa winery are organic, biodynamic and vegan-friendly.

But the vegan-friendly tick logo has only recently been printed on the back label.

Another South Australian winery, Angove Family Winemakers, is taking its branding one step further.

The next release of its organic range — due within weeks — will add "vegan friendly" to the front of the bottle.

Richard Angove is the co-director of the Riverland-based winery, which now has an annual turnover of $55 million.

He said the label change was in response to continual online enquiries as to whether their wines were vegan.

Mr Angove has seen attitudes towards non-conventional wines change a lot.

"Wines that are organic and vegan are [now seen as] just as good, if not better than their non-vegan counterparts," he said.

Both Kalleske and Angove have national and international wine awards to back them up and not only in organic categories.

One of the biggest names in winemaking, Yalumba, said all of its wines produced since 2011 were vegan-friendly and that included cask wine.

Menu features 22 cuts of meat and vegan wine options

"The good thing about vegan wine is it's good for everyone — vegans and, equally, those who love their big juicy steaks," says Mr Kalleske.

It's a view that Queensland restaurateur Steven Adams shares.

His steakhouses in Brisbane's CBD and the Gold Coast offer 22 cuts of meat, and hundreds of wines, including biodynamic, preservative-free and vegan.

"It's really sort of grown in the last seven to eight years," Mr Adams said.

"We're looking for broad spectrum, obviously high-quality brands we can trust, not necessarily wines that are known, and biodynamic and organic is an increasing appetite and something we are embracing."

He said diners were increasingly looking for healthy and sustainably produced food and wine, with fewer additives and minimal intervention.

Chinese customers looking for the same thing

The organic wine category, which includes biodynamic and vegan wine, is still a niche market, accounting for less than 1 per cent of Australia's wine exports and a similar amount of domestic wine retail sales.

Grapes at the Kalleske winery are grown according to biodynamic principles. ( ABC News: Dominique Schwartz )

Grapes from the morning's harvest are tipped into the crusher at the Kalleske winery in South Australia. ( ABC News: Dominique Schwartz )

Grape skins are shovelled out of the fermenter after the wine has been drained off. ( ABC News: Dominique Schwartz )

After the grapes have been in an open-top fermenting bin for seven to 14 days, the free-run juice is siphoned off. Yes, it is actually wine. ( ABC News: Dominique Schwartz )

But things are changing.

"The growing trend in the community for products that are seen as environmentally friendly means the production and export of organic and biodynamic wines in Australia has been rapidly growing," according to industry body Wine Australia.

According to figures compiled by Wine Australia for the ABC:

Exports in the organic category have risen by an average of 40 per cent annually over the past four years

Exports in the organic category have risen by an average of 40 per cent annually over the past four years Those exports were worth $14.5 million in the year to March 2018

Those exports were worth $14.5 million in the year to March 2018 Sweden and the UK are Australia's biggest organic wine markets

Sweden and the UK are Australia's biggest organic wine markets Over the past year, China rocketed into third place with organic exports soaring a whopping 170 per cent.

Wellness trend catches up to wine drinkers

Domestically, the growth in organic wine retail sales far outstrips that of non-organic wines, according to strategic market researchers, IRI Worldwide.

Those sales totalled $24.2 million in 2017, up nearly 40 per cent from a year earlier, it said.

IRI Worldwide's Health and Wellness Survey 2017 found a clear consumer trend towards "naturals".

Two-thirds of shoppers surveyed said they looked to purchase products with as many natural ingredients as possible, driven by the perception that such food will be healthy and nutritious.

Shoppers put more importance on products being free from artificial ingredients, preservatives or additives, than on being organic, the survey found.

All of which bodes well for winemakers seeking to keep their wines as natural as possible.

It comes as no surprise to Troy Kalleske.

"Organics is trendy now and some see it as a revolution but it is going back to basics, what's been happening for thousands of years," he said.

You can see more on this story on Landline on ABC on Sunday at 12:30pm.