Kiwis like their beer – we have more breweries per capita than anywhere else in the world.

With more than 200 craft breweries nationwide, experimentation to produce beers with new and different flavour experiences is widespread, with the major flavour component coming from hops.

New Zealand has some of the most sought-after hops in the world. Not only does the hop industry benefit from New Zealand's reputation for environmental sustainability, but our hops have unique flavours brewers, particularly those with a taste for something different, search for.

Most of the hops were born in a small plot of land at the top of the South Island, courtesy of Plant & Food Research.

"Around 95 per cent of the commercial hop industry is Plant & Food Research-bred cultivars," says Dr Ron Beatson, who has been a hop breeder for the past 38 years. "The most successful have really unique flavours – they might give beer a tropical, passionfruit flavour or the same notes as a Marlborough sauvignon blanc."

New Zealand's hop breeding programme began in the 1950s because of a disease affecting production of the imported American cultivar that was being grown at the time. The DSIR, as it was then, established its hop breeding programme on a small research site outside of Motueka at the top of the South Island. With high sunshine hours, even rainfall throughout the year, and sheltered from strong prevailing winds, it was an area that suited hops down to the ground.

The original breeder, Dr Rudi Roborgh, spent more than 20 years working with hops. Having solved the disease problem by releasing new resistant cultivars in the early 1960s, he went on to breed seedless cultivars (seeds have no value in the brewing process but can make up 20 per cent of the harvest weight).

When Roborgh – who had the bar, Dr Rudi's, named after him in Central Auckland – retired in 1973, he had been responsible for the development of six new cultivars of hops. That began New Zealand's journey towards unique hops that could grow in our environment and meet the needs of brewers.

His successor, Tony Frost, began his 10-year tenure with a focus on improving production but then started to experiment with breeding hops with different aromas. When he retired in the mid-1980s, Beatson took over – he continued Roborgh and Frost's breeding work and his legacy is 14 cultivars with a range of flavours brewers love.

"We evaluate up to 5000 offspring from different combinations of parents every year," says Beatson. "We only take the girls forward – the boys don't make the hop cones needed for brewing.

"It takes about two years for the plants to grow and be ready for evaluation – and they need to have good yield, mature at the right time for harvest, and be able to be machine-harvested. If they tick all those boxes, we start using them in small brews in our pilot brewery to evaluate them for good beer flavour characteristics."

New Zealand hops are classified as a speciality 'New World' hop – the 1500 tonnes produced each year only account for about 1 per cent of total hop volume used around the world. About 85 per cent of the harvest is exported to more than 20 countries round the world, generating almost $40 million in revenue.

"New World hops, like those we produce in New Zealand, are offering brewers something new, whereas hops from Europe and the USA are still mostly targeted at traditional beer flavours. Our hops are a bit unusual; craft brewers love that point of difference," says Beatson.

Most of Plant & Food Research's cultivars – 17 of which are being grown in New Zealand at the moment – are sold through NZ Hops Limited, a grower cooperative. This includes the cultivars Nelson Sauvin and Motueka, which make up nearly 50 per cent of the annual crop, as well as more recent cultivars, such as the latest release from the breeding programme Nectaron - named in part to recognise Beatson's contribution to the success of the industry.

The two organisations have just signed a deal which will see this relationship continue for at least another 10 years, with a focus on breeding more new cultivars with unique flavours.

The future of hop breeding for Plant & Food Research is centred around new breeder Kerry Templeton, who has been working with Beatson since 2017. A keen home brewer himself, Templeton is on a mission to find more unique flavours New Zealand is known for.

"Brewing is a fashion industry – brewers and beer drinkers are always looking for something new, so we have to keep up. What's hot today might not be in 10 years' time and it takes at least that long to breed a new cultivar," says Templeton.

"Being able to keep ahead of the trend means New Zealand's hop industry can maintain its reputation for offering something different and keep growing into the future."

New technologies that could automate some of the process will make the search a bit easier. New genomics tools allow breeders to identify parents and offspring with potential by just analysing a leaf. Finding a way to teach a computer what makes a good tasting beer by analysing the chemical profile would make things faster.

"Creating small batches of beer in our pilot brewery and inviting local brewers to taste them is definitely a perk of the job," says Templeton. "Though it would be great if we could train a computer to weed out the selections that don't taste that good."