Can a scientific formula be used to brew the perfect beer?

Scientists and amateur beer brewers Scott Brownless and Chad Husko are seeking an equation to brew the perfect beer.

The pair, who work as physicists by day, moonlight as chemists in the evening, using their science training to give their ale an edge over other brews.

"We have a different way of looking at the world and we thought we'd bring that to the brew scene," said Brownless.

There was a lot of superstition in amateur brewing, said Brownless.

"People do something for years and it works so they keep doing it, but if you haven't tested a hypothesis you won't know if that thing is necessary to make your beer good," he said.

Slight temperature or pH changes, and timings for various ingredients will all affect the end product.

For every batch of lager the scientists brew, they collect reams of data, noting subtle changes in every recipe.

"We're applying the scientific method," said Dr Husko, an experimental physicist at the University of Sydney.

"In brewing we switch roles and Chad does most of the theory and calculations and I'm the one who goes around making it," said Brownless, a theoretical physicist also from the University of Sydney.

The brewers even run specially designed control experiments, changing a single variable to see how that affects their ale.

With their beer data, the pair are developing a metric to define specific flavours and characteristics.

When consumers say they like a beer because it is fruity or smoky, Brownless and Husko want to know the specific chemistry behind those characteristics and use that to develop recipes for their next brew.

"We're trying to find out what matters and what doesn't," said Brownless.

Science has even inspired their brewery's name, Angstrom, after the unit of measurement used for objects the size of atoms.

"We are physicists so we thought we'd go with something physics related," he said.

There's a long-standing role of science in brewing. It could even be considered one of the oldest forms of biotechnology because the practice dates back at least 5000 years, possibly longer.

In the past two years the craft beer industry, whose members produce less than 40 million litres a year, has grown dramatically.

The craft beer industry association chairwoman Peta Fielding said craft brewers were not usually trying to create the "perfect" beer but aimed to have fun and bring that essence to their brew.

Part of the joy of craft brewing was being creative, said Fielding. But the co-founder of Burleigh Brewing Company acknowledged there was a great depth of science behind the practice.

"Science really does need to be part of it or else you'll be dumping a lot of creative experiments."