After finding two wild varieties of hops in the Adelaide Hills, grower Stuart Binnion thinks he has discovered why they are growing in the bush.

Key points: Hops are traditionally used in beer brewing and the booming craft beer industry means there is renewed interest in vintage varietals

Hops are traditionally used in beer brewing and the booming craft beer industry means there is renewed interest in vintage varietals It is believed that the plants may have been grown and used by bakers to keep their yeast mother healthy in the days before widespread refrigeration and powdered yeast

It is believed that the plants may have been grown and used by bakers to keep their yeast mother healthy in the days before widespread refrigeration and powdered yeast This is the theory one hops grower has formulated as to why two different hops species were found by him growing wild in the Adelaide Hills

"We started doing a bit more research into why there would be wild hops growing up through that creek there," Mr Binnion said.

"The theory we've come up with is, prior to the 1950s when the US military came up with powdered yeast, we reckon some of the bakeries up here must have been growing hops to help preserve their yeast mother."

Those bakeries are now long gone, but the hops plants that took root in the Adelaide Hills are still growing and have now been discovered.

Hops are traditionally used in brewing beer to add flavour and bitterness, but the plant also contains antimicrobial properties.

Mr Binnion said he believes hops cones were used to keep the yeast mother healthy before commercial refrigeration was widespread in Australia.

"So we kind of cottoned on that there might be a whole bunch of hops out in old bakeries around the country," he said.

"Which is really interesting because they would be varieties that haven't been seen in a very long time."

Cultivating the cones

Mr Binnion now has about 30 plants of the new varieties on his Mylor property in the Adelaide Hills.

Hops farmer Stuart Binnion assessing the crop. ( Supplied: Silver Springs Hops )

He said he hopes he will have enough dried this year to produce a batch of lager with the wild hops.

"We can actually reproduce some kind of beer that was made 100 years ago," Mr Binnion said.

Home brewers boom

Freshly picked hops need to be either used or dried immediately. ( Supplied: Fresh Hops Co-op of Australia )

"We started [growing hops] because of the boom in craft beer breweries," Mr Binnion said.

He said the market is continuing to grow, and most of their supply of hops cones go to local breweries or home brewers.

"I sold my entire dried stock last year, so quite happy with that," Mr Binnion said.

"It's a local product that doesn't have to travel very far and can be turned into a South Australian harvest ale."

Farmers climb the hops up a twine that can hold 50 kilograms of the plant. ( Supplied: Silver Springs Hops )

Mr Binnion said it is a strict processing system.

"They have to be used within 24 hours or they have to be dried," he said.

"If they're not going into beer fresh, they need to go into an oast house, which is either warm to about 36 degrees with a lot of air flow, and stay in there for 12–24 hours."

Mr Binnion said he is looking to expand his collection of wild hops, which could give rise to new types of beer.