Traditional beers are made by mashing barley with water, adding hops, boiling the mixture, and allowing it to ferment where the yeasts turn the sugars into alcohol.
Non-alcoholic beers start the brewing process off in the same way, but the alcohol is removed, the fermentation stopped before lots of alcohol is produced, or the beer is diluted to lower its alcohol percentage.
Let’s look at each of these processed in a bit more detail.
Dealcoholised beer is made using the traditional fermentation process, and alcohol is removed at a later stage.
The alcohol is removed in one of the following three ways:
Alcohol boils at a lower temperature than water, meaning alcohol can be removed from the beer by heating the beer to the alcohol boiling point.
By heating beer under low pressure, the alcohol will evaporate, but the flavour of the beer will remain.
Hi-tech techniques can also be used to retain flavour, like using a spinning cone column system, which separates the flavour from the alcohol, and then the flavour is added back in once the alcohol has been cooked off.
Water vapour and gas stripping
For this process, the beer is heated in a vacuum, and then water vapour or nitrogen gas is passed through it. The vapour or gas carries the alcohol molecules away, leaving an alcohol-free drink.
Reverse osmosis uses chemistry processes and high pressure to force beer through a permeable membrane. The membrane holds back large molecules, like flavour compounds, but allows smaller water and alcohol molecules to pass through. This results in a highly concentrated beer product without alcohol.
The water and alcohol molecules are then separated, and the water is added back into the beer, retaining the beer’s flavour.
Alcohol is a result of fermentation, so if you are able to limit fermentation to a point where only 0.5% alcohol is produced, then the beer will be considered low-alcohol or alcohol-free. Again, there are three common ways to limit fermentation:
Limiting fermentable sugars
Yeast breaks down the sugar to form alcohol. By limiting the sugars in the beer, less alcohol will be produced.
This can be done by using grains like rice or maize that contain less fermentable sugars, or fermentable sugars can be extracted during the mashing process. This will produce light beers or beers with little or no alcohol.
Using special yeast strains
Special yeast strains can be used to limit fermentation. These include strains that only produce low levels of alcohol or that are unable to ferment certain sugars.
Although this is an easy way to produce a light beer, these beers may have higher sugar content and be sweeter. Some of these yeast strains may work with less sugar but produce lactic acid, which results in a sour taste.
Slow or stop fermentation
Processes in the fermentation tank only occur under perfect conditions – such as the right temperature. By heating or cooling the fermentation tank or increasing the pressure, the fermentation process can slow down or stop.
Non-alcoholic brews made using this process may have a sweeter taste, and some report it tastes “unfinished” when compared to regular beer.
Dilution involves the traditional process to make full-strength beer, using hops and barley to make a rich, concentrated beer with a lot of flavour. After fermentation, the concentrated beer product is diluted with water until a 0.5% alcohol level is reached. The beer is then re-carbonated to make the perfect non-alcoholic beverage.
Fermentation does more than just add a buzz to beer. It is important to add a depth of flavour and smell. Despite this, not all beers go through the fermentation process.
Although most non-alcoholic beers undergo some form of fermentation, some breweries completely avoid fermentation and use other special techniques to produce a beverage that looks, smells, and tastes just like beer.
Brewers use several methods to produce non-alcoholic beers. No matter the method used – whether alcohol was removed after fermentation or if no fermentation occurred in the first place – alcohol-free beer is here to stay.
Alcohol drinkers and those abstaining from alcohol will find non-alcoholic beer with complex flavours and aromas to tantalise their tastebuds!