The high science of low-alcohol beers
By Phil Mellows
Brewing is both an art and a science. It’s not simply a matter of creating flavoursome recipes for beer. To make it work, the brewer must master some hard science to harness natural processes.
While astronomers turn their telescopes to the skies, brewers are focused on the microbiological magic that happens when yeast meets sugar and converts it into alcohol and carbon dioxide, adjusting variables such as raw materials, timings and temperatures to achieve the desired result.
They are wrestling with nature, and when it comes to low and no alcohol beers it’s a heavyweight bout as they grapple to restrain yeast’s appetite. So how do they do it?
NABLABs, as we once clumsily called no-alcohol and low-alcohol beers, have a bad rep that dates back 30 or so years when the main goal was to produce an alternative beer for drivers, a distress purchase – they were drinking it because they had to, rather than because they liked it.
As not-drinking has become a more positive choice, however – expressed by champions of the ‘new sobriety’ such as Club Soda –brewers have responded, and a proliferation of craft styles have encouraged many drinkers to reappraise alcohol-free.
Key to this shift, and the strong growth of the AF beer market, are new science-driven techniques to manipulate ABVs and take them below 0.5%.
In the 1980s and 1990s methods were limited to halting fermentation before it has finished its job, akin to withdrawal contraception, and heating up the beer to evaporate the alcohol.
Now technologies have been developed that lessen the impact de-alcoholisation can have on the flavour and mouthfeel of beer, including vacuum distillation that burns off the alcohol at lower temperatures, and reverse osmosis, essentially a kind of filtration.
But perhaps the most interesting approach is one that, rather than requiring expensive machinery, relies on the brewer’s skill and carefully chosen ingredients to brew a beer in the normal way to a very low ABV.
Big Drop Brewing, which has created a remarkable variety of 0.5% beers over the past few years thanks to head brewer Johnny Clayton, formerly at Wild Beer, has arguably led the way in this.
Clayton uses a ‘lazy’ yeast that’s bad at converting sugars to alcohol and plays around with temperatures to disrupt the process even more. He also brews with less grain, so less sugar, and replaces the flavour and complexity that might be lost in doing that by using up to 20 different grains including strains of rye, wheat and oats, as well as the usual barley. Lactose is sometimes added to counter the thin mouthfeel often associated with AFs.
The quality improvements are one reason why alcohol-free is gaining acceptance. Another is that craft beer drinkers are increasingly open to trying new flavours and styles,
Brewers can add complexity with bold use of hops and other ingredients. Yuzu Pale, from Welsh microbrewery Drop Bear Brewing, was a favourite of mine among those the British Beer Breaks team tasted during lockdown and it’s interesting to see, at the other end of the scale, that the world’s biggest brewer, AB InBev, has produced a 0.0% version of Leffe abbey beer and is not relying solely on its rather bland AF lagers.
Wheat beers and sours tend to work well at low strengths, too, while Big Drop’s bestseller is its Milk Stout, a style which is, of course, defined by its use of lactose.
But if low and no alcohol brews are really going to establish themselves as a sustained, significant and satisfying part of the beer drinker’s repertoire, it’s the white-coated boffins in the brewing lab that we need to thank.
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