Like many millions around the world, you probably never gave a second thought to how beer is made. However, now there are alcohol free and non alcoholic beers that taste remarkably similar to alcoholic ones, curiosity leads you to wonder how they do this
Non alcoholic beer can be made in a number of ways. Beer can be dealcoholisd by vacuum distillation or reverse osmosis, you can reduce alcohol production with limited fermentation or special yeasts, you can brew the beer fermentation free or even just dilute an alcoholic beer to a lower ABV
Each of these techniques has positives and negatives and an individual brewer many use a number of different methods for different beers they produce.
Before we have a further look as just what each of them are it might be useful for a whistle stop tour of how alcoholic beer is made.
How is beer made?
For the most part, non alcoholic beers are made from or in a similar way to alcoholic beers, so having a quick recap of this step will help understand the full process.
In order not to complicate things, let’s just look at a standard beer with the age old 3 ingredients (plus yeast)…
- Water – Water is by far the biggest ingredient and therefore a big flavour contributor. You don’t want to start with
- Malted barley – This provides a source of sugar for the yeast to turn into alcohol. The malt gives flavour and colour to the beer. For a stout you will have a small amount of highly roasted malted barley for a dark colour and chocolatey flavours. A lager will a lightly roasted malt for a light colour and flavour
- Hops – Hops is a preservative as well as adding aroma and flavour. There are an increasing number of hop varieties grown around the world with many flavour notes, most have some form of citrus
The brewing process
Once you have the required ingredients for your desired beer, you have to brew it. This consists of these steps…
- Milling – The barley is crushed to form a grist. Grist is grain that has been separated from its chaffs
- Mashing – The grist is transferred to a “mash tun” container where is is mixed with liquor (hot water) and left to soak. Natural enzymes work to convert the start in the malted barley into sugar. The resulting sugar solution is called a sweet wort. The sweet wort is separated off for the grains.
- Boiling – The sweet wort is boiled with the hops in a “copper”. The earlier the hops are added the more bitter the beer will be.
- Fermentation – Yeast is added to turn the sugar into alcohol and carbon dioxide. The yeast itself adds a distinctive flavour with different parts of the world using different yeast strains.
- Maturation – before bottling the beer must be conditioned. Lagers need a longer time at cool temperatures than ales. Additional hops can be adde for flavour which is called “dry hopping”
How is non alcoholic beer made?
Ok, so you have a rudimentary understanding of the basic brewing process so it should be easier to understand the additional steps to make a non alcoholic beer.
This is similar to how non alcoholic wine is made. If you want to read more on the see my article on the topic.
You can probably guess that “dealcoholisation” means removing alcohol from a regular beer somehow.
If you heat a beer to evaporate off the alcohol you need to get it to 173.1°F. At this level you damaging a lot of the aromatic compounds and flavours which isn’t so good for the end product.
The answer is to heat the brew in a vacuum. When you do this the boiling point of the alcohol is reduced to 93.2°F. At this more gentle heat, you are able to keep a lot more of the flavour.
Reverse osmosis, cold filtration
The second method is reverse osmosis. Brewers use very high pressures instead of heat. The beer is forced against a very think membrane filter. This filter separates water and alcohol from the beer’s phenolic components. Phenolic compounds are responsible for aroma
After this the brewers use distillation to separate the alcohol. Lastly, they bring back the remaining water with the aromatic components. As there is less water than the water/alcohol mix, they usually have to add more water to get it back in balance.
The less cultured but easier version of the vacuum distillation is just normal boiling. Alcohol has a lower boiling point than water so you heat the beer to this level. The alcohol evaporates off, leaving a non alcoholic beer.
You will loose flavour to evaporation and heat damage so although this is the easiest method, it is not used often for mass production commercial beers.
Clearly if you make less alcohol in the brewing process, then there will be less to get rid of at the end. This cuts costs and reduces the sometimes harmful effects of dealcoholisation on the beer.
This can be done in 2 different ways…
You can limit fermentation but reducing the amount of sugar available for the yeast to turn into alcohol. Using grains like rice or maize which naturally contain less sugar is a great way to achieve this.
You can also extract sugar directly from the wort before you ferment it.
Some brewers can use a process called arrested fermentation. Yeasts are inactivated or removed before they can start producing alcohol in any great volume. It is done by rapidly cooling down the fermenting beer to close to zero, putting the yeast to sleep.
The other way to reduce alcohol is to use a specialised yeast which produces little to no alcohol. These yeasts can still have a positive effect on the flavour of the beer but produce little alcohol.
See video below of a new specialised yeast.
You would assume the best way to create an alcohol free beer is for no alcohol to be produced in the first place.
No fermentation brewing is done by withholding yeast to the wort and therefore eliminating any possible production of alcohol.
Fermentation free can be difficult though as it will often mean making big changes to recipes or the production process which can affect flavour and price of the resultant beer.
Like boiling, dilution is probably the easier to understand.
If you have a 5% beer but want a 0.5% beer you can just add water to dilute it down. After it is diluted you can recarbonate to get the fizz back.
The obvious drawback is you will dilute down the flavour of the beer and could be left with a thin, fizzy water constancy beer.