Barley has come out of a five-year study into the flavour of beer proving that some varieties do produce better beer than others.

The study aimed to settle the centuries-old brewing debate – what makes a perfectly flavoured pint? It’s been the obsession of brewers for centuries.

Hops, water, or yeast have all been held up as the main cause of the taste of beer. But science has proved barley – and one of them none other than the old favourite Golden Promise – has as much to do with flavour as anything else.

The discovery, during the five-year study involving researchers at The Sainsbury Laboratory, in Norwich, along with colleagues in the US, exploded the long-held myth that it was the malting process not the barley that contributed to the flavour and aroma of beer.

Varieties of barley are chiefly selected for their suitability for the malting process and the efficiency with how barley is turned into sugary malt. However, many brewers insisted that certain barley varieties did contribute to flavour above and beyond the malting process.

In addition to genetics, they believed, environment and location – what the wine industry calls terroir – also played a part. It turns out they were at least partly right.

Dr Matthew Moscou, one of the authors of the study, said: “The malting process directly impacts the wider profiles of flavour – how you get a pale ale, lager, or a porter – but what this study showed was that the subtle flavour profile of the barley variety selected carried through that process.

“This provided the motivation to look into our seed base and start looking at those cultivars that were grown in the past and asking what kind of flavour profiles we can bring into modern breeding.”

Researchers selected two barley cultivars, Full Pint and Golden Promise, which had different flavour profiles when used to brew beer. The cultivars were crossed and modern breeding techniques used to create a population of 200 lines of barley to observe useful field traits.

To test whether 'terroir' applied to barley flavour, they grew populations across three sites in Oregon, in the US. The barley was harvested, micro-malted and micro-brewed using a customised scientific approach that ensured consistency between batches.

Around 150 beers were prepared for sensory testing using a trained panel – people with sensitive palates employed by the brewing industry who know how to differentiate between many flavours.

The study found that the genetic effect was larger than the environment. “Major targets in barley breeding is yield and malting quality, said Dr Moscou. “But this study showed that the flavour profile has little to do with the malting characteristics. That’s important because it says you can breed barley for malting – but you won’t necessarily be breeding for flavour.”