How is Low and Alcohol Free Beer Produced?
Low and alcohol free (AF) beers have certainly improved in recent years, particularly with the rise in craft breweries introducing these beers into their range, but what is the difference between a LA/AF beer, and how are they produced?
What is the difference between low and alcohol free beer?
The main difference between these two beer styles is (quite obviously) the amount of alcohol contained in each:
- Low Alcohol Beer - in the UK, this means any beer containing less than 1.2% ABV
- Alcohol Free - in the UK, Government guidance states that AF beers should be less than 0.05% ABV, although producers may choose not to follow this guidance and instead market beers with less than 0.5% ABV as AF
How is low and alcohol free beer produced?
Brewing beer typically follows 3 main steps:
- Mashing - sugars are extracted from fermentables, or grains through the process of steeping in hot water, or 'mashing' to create wort
- Boiling - hops are added and the wort is boiled which helps to remove bacteria, unpleasant aromas and to drop out unwanted proteins. Depending on when hops are added to the boil, bitterness and aroma can be adjusted
- Fermentation - yeast is now added to the cooled, boiled wort. The yeast cells eat up all of those lovely sugars extracted during the 'mashing' stage while simultaneously producing alcohol and carbon dioxide (CO2) as bi-products
Low and AF beer generally follows the same basic brewing steps as your regular, full strength beer, but with additional steps added. Let's take a look at three of the most popular techniques.
De-alcoholisation or Thermal Extraction
A cost effective way for breweries to produce AF beers, but with the unfortunate consequence of also removing aroma and flavour from the beer.
Alcohol has a lower boiling point that water which allows brewers to boil off the alcohol content until the desired ABV is achieved.
Reverse Osmosis
Reverse osmosis (RO) is the process of forcing the beer through an incredibly tight filter, with holes just big enough for water and alcohol molecules to pass through, but not so large that other compounds such tannins (colours) and acids can pass.
Once RO is complete the watery, alcohol solution can then be distilled to remove the alcohol to the desired ABV. This can then be reintroduced to the other compounds removed earlier on.
Interrupted Fermentation
As fermentation progresses more and more alcohol will be produced until there is no more fermentable sugar left for the yeast to digest. By interrupting this process at the desired ABV it is possible to achieve a low alcohol beer.
The downside to this is that the flavour and aroma profiles we love about beer are crafted during the fermentation stage. Interrupting this process may lead to unwanted flavours.
In Summary
Low and AF craft beer is definitely seeing an uptick in the UK, and why not? As de-alcoholisation techniques continue to evolve and improve, new and exciting types of AF beer are making their way to market. Click here to take a look at our selection of AF craft beer now available.
