New hops may change taste of N.Z. beer

Press, Volume CXI, Issue 32562, 23 March 1971, Page 17

New hops may change taste of N.Z. beer

(From Our Oizn Reporter) NELSON, March 22. The development of three varieties of seedless hops at the D.S.I.R. Hop Research Station at Riwaka could revolutionise the brewing industry in New Zealand and lead to new exports.

The hops, developed by the station superintendent, Dr R. H. J. Roborgh, and his staff, are past . the experimental stage. Within four years it is probable that all hops grown in New Zealand will be seedless.

Since most brewers overseas prefer, the milder seedless hops, New Zealand could compete on world markets, and particularly for Japanese contracts.

New Zealand beer, already highly praised in many parts of the world, could also become a big earner of foreign currency, by using the new hops.

The crowning achievement! of his 20 years work on hop! research, Dr Roborgh says, j would be to see an export! trade established. The way is i now open. Japanese interest While overseas recently, Dr Roborgh visited Japan, one of the largest importers of hops, hop powder and hop extract in the world. He took with him samples of the seedless varieties developed in New Zealand, and was given an attentive hearing by an audience of brewers.

They were particularly interested in the high resin content of the new varieties. The resin is secreted in each hop flower and is the actual material required from the hop by brewers. The new seedless hops have a resin content of between 10 and 12 per cent compared with a content of only 6 per cent in the varieties exported to Japan by the United States and Germany. The Japanese were quick to appreciate that they would need to import only half their present supplies if the hops contained twice the resin content.

“I see no reason why, if the hops are marketed in Japan, that the hop acreage in New Zealand could not be trebled, to the advantage of the growers and the country as a whole,” Dr Roborgh said.

After-taste For many years, overseas experts have praised New Zealand beer. Many of them, however, have commented I unfavourably on the harsh after-taste, the hallmark of the seeded hop. It is not found in beer brewed from the seedless hop. This after-taste, Dr Roborgh explains, originates in the i seed coat which contains, tannin, the same black substance which is found in unwashed teacups. Each seeded hop contains between 12 and 14 seeds, compared with a world-recognised standard of one seed in a seedless hop. With the exception of Great Britain, New Zealand and Tasmania, all the hopgrowing centres of the world produce seedless hops. The growing industry in New Zealand has flourished in the Nelson province for many years, and from a comparatively small acreage (660) have come the requirements of New Zealand brewers. At times, however, supply has exceeded demand and disposal of the surplus overseas has been made difficult by the type of hop. 10-year project Ten years ago. when it became apparent that oversupply was having a detrimental effect on the industry, growers and brewers decided to seek the introduction of a seedless hop. On the understanding that ex-

periments should be completed within 10 years, the Brewers’ Association of New Zealand undertook to buy all surpluses. Growers, in turn, gave an undertaking to try to limit production to New Zealand’s requirements. Dr Roborgh began his experiments by attempting to grow hops on the female plants without having them pollinated by the male plants. It has been the practice to distribute one hopless male plant to every 80 female plants in a garden for pollination. He thought that by removing the male pollen from the females, the hops |on the female bines would ■not be fertilised so that no i seeds would be formed.

He chose Collingwood, separated from the Motueka district by the high Takaka Hills, for his first major experiments. He planted a number of female plants and awaited results. They were disappointing. The females 'grew the hops, but they were of peanut size and useless.

From these results Dr Roborgh deduced that the male pollen, as well as fertilising the female, also provided hormones necessary for 'the Tilling out of the hop flowers. Early setback After this setback, Dr 'Roborgh imported overseas ‘seedless varieties from the (United States, Germany, (Jugoslavia and Czechoslovakia for experiments. In i their new foreign environjment, they failed to produce. Seven years of the decade i set for experimentation had (passed without any definite (results when Dr Roborgh (brought science and the navel (orange to his aid. The pipless (navel orange had been developed by treating the (chromosomes of the ordinary I orange with the alkaloid, ; colchicine. He applied the (same material and technique I —an extremely complicated one—to the shoots of the (female hops, then allowed the (flowers to be pollinated by :the males.

Three varieties • The result was a sterile, (seedless hop; a hop which Shad been exposed to the (male pollen hormones and which waxed fat and strong.

In this manner the station has been able to develop three varieties of seedless hops. Cuttings from the bines have been propagated, thus allowing growers, within a comparatively short space of time, to obtain thousands of cuttings. Today, 25 growers are growing these three varieties on half-acre plots in the district. Dr Roborgh awaits the completion of the harvest with intense interest and confidence.