The production of beer and other alcoholic drinks has been around for centuries, so as human’s we have got pretty good at it.
The largest beer breweries in the world have spent lots of money developing and refining their manufacturing process to ensure that every batch of beer is near identical.
Brewing beer however, is not as simple as mixing all the ingredients together and putting in bottles, can or kegs. The process of fermentation is important for both alcohol production, and the flavours and aromas that you associate with all of these beers.
So, when it comes to brewing non-alcoholic beers, finding a way to re-create the flavours and aromas of an alcoholic beer – with less or no alcohol – requires a different brewing approach.
Fortunately, as the popularity of non-alcoholic and low-alcoholic beers continue to grow, finding ways to brew beer with lower alcoholic content continues to get more advanced.
In this article, we shall investigate some of the popular production methods for low and no alcohol beers.
How is alcoholic beer made?
Before we investigate the ways in which no or low alcoholic beers are made, it is important to revisit the way in which alcoholic beers are made.
This is important, because it makes the process of explaining how the lower alcohol versions are created.
In short, grains such as barley or oats are added to hot water to create what is known as a ‘wort’. The hot water extracts and breaks down the starch in the grains to produce a sugary liquid.
The wort is transferred to a separate vessel, where the hops are added. The hops are added to add additional flavours and aromas to the wort before it is left to cool.
Once cooled, yeast is then added to the wort. The yeast reacts with all of the sugars that were extracted from the grains to produce alcohol and carbon dioxide.
Although additional processing may occur, in essence, the beer is produced due to yeast being added to the wort, known as fermentation. Not only does this step help add the alcohol and bubbles that we associate with beer, it is also an important step for developing much of the flavour and aroma of the beer.
Because the process of fermentation is so crucial to the taste and aroma we associate with beer, it is almost impossible to do so without producing alcohol.
However, there are some ways around this well-known beer producing method. The five main methods of creating non-alcohol beer are the following:
- Limited fermentation
- Fermentation free
- Special yeast
Let’s investigate the methods below:
Dealcoholisation is the method of removing alcohol from a beer after it has been made using the traditional steps mentioned above.
Due to some simple science, there are a few different ways to remove alcohol from a liquid solution.
One method of dealcoholisation is via steam distillation.
In a large vessel containing a spinning cone column, the alcoholic beer is gently heated.
As it is heated, volatile components such as flavour, aroma and crucially alcohol, are evaporated from the liquid solution.
The gaseous molecules then pass through the cone column and cool on the metal surface. As the cool to a liquid, they are collected and separated from the main solution.
A simple schematic of the process is shown below:
The gas stripping method is similar to the steam distillation method mentioned above,
The beer solution is gently heated, to allow the volatile molecules to escape into the headspace of the vessel.
The gaseous, volatile components are then removed from the vessel using an inert gas or water vapour to remove them completely.
If you paid attention in your high school science lessons, reverse osmosis will likely ring a bell.
The alcoholic beer solution is forced through a semi-permeable membrane which allows small molecules such as water to pass through, but traps larger molecules such as ethyl alcohol – or alcohol.
The trapped molecules are removed, and you are left with the non-alcoholic version of your beer!
Which method is best?
All three methods work in a similar fashion to remove alcohol molecules either by their size, or by the low boiling points.
Whilst all three are tried and tested methods, they can also be susceptible at removing other molecules – importantly the flavour and aroma molecules that are so important to a non-alcoholic beer.
However, there is the possibility of separating any of these molecules that have been accidentally removed from alcohol molecules and re-added back into the non-alcoholic beer solution!
2. Limited fermentation
Rather than removing alcohol once it has been produced during the fermentation process, the limited fermentation process seeks to restrict alcohol from being produced altogether.
This can be done a few ways; by carefully controlling the ingredients and conditions used.
Alcohol is produced when the yeast and sugars react, under favourable conditions.
But by limiting any of these factors, you can interrupt the alcohol production.
For example, you can use grains that are low in sugar content, use a yeast that is slow-acting, or inhibits alcohol production, or alter the environment of the fermentation, such as amount of time or temperature.
Overall, limiting fermentation does not typically result in alcohol-free beers, but low-alcohol alternatives.
This one is pretty simple.
Rather than removing, or preventing alcohol being produced, you take a known concentration beer solution and dilute it with additional water.
Breweries that use this method, typically produce a solution that is ultra-concentrated with flavours and aromas from the hops, to ensure a full flavour once dilution has been occured.
It is common for dilution to result in a flat beer, but carbon dioxide can always be added at a later processing step too.
4. Fermentation free
Rather than having to mess around with removing or altering beer containing alcohol, you can simply remove the fermentation step and avoid producing alcohol altogether.
Although fermentation creates the alcohol and carbon dioxide, it is also an important step for adding flavour and aroma to your beer.
Without the fermentation step, you can guarantee an alcohol-free beer, albeit one that has slightly different taste characteristics. This results in a non-alcoholic beer that is typically sweeter than normal.
Fermentation free beers are popular is Islamic countries where the consumption of alcohol is prohibited, and often deemed haram.
5. Special yeast
The fermentation step of beer is an important step for flavour and aroma.
Rather than avoid the fermentation step, or go through the hassle of removing alcohol or diluting it down, it is possible to use specialised yeast blends that still create fermentation but without the alcohol production.
Special yeast molecules that have been genetically modified are capable of providing a solution here.
However, to ensure great tasting, alcohol free beer, lots of research and development is required as this is still a relatively new area of beer production.
It is likely that as non-alcoholic drinks become more popular, the advancement in specialised yeast strains will go from strength to strength!
Which method produces the best beer?
Of all the five methodologies listed above, there is no one ‘best’ solution.
Most of these methods require most time and resources to develop non-alcoholic beer than the hard stuff. So choosing the best solution can often be decided based on time and money for each individual brewer.
It is not uncommon for brewers to use more than one solution listed above in harmony with another, to ensure maximum alcohol removal whilst retaining the full flavour and aroma profile.
It can also help explain where the price of non-alcoholic beers are similar to alcoholic beers, and why different terminology is used to classify alcohol free, dealcoholised beer and low alcohol beer!