This week I take a look at some popular methods for making low alcohol beer at home. Commercial brewers use similar methods when brewing low alcohol and non-alcoholic beers.
Low Alcohol and Zero Alcohol Beer
Here in the US, non-alcoholic beer is defined by the US Food and Drug administration as beers containing alcohol levels of 0.5% ABV or less. Zero or no alcohol beer is defined as having an alcohol level of 0.05% or less, though in practice only a handful of commercial beers in the US are truly 0% alcohol. While state laws vary, non-alcoholic beer may be sold to those under the legal drinking age of 21 in most states.
The UK adds an third level of low alcohol with a higher limit of 1.2% ABV, while much of the EU considers beers below 0.5% ABV as alcohol free.
Traditionally, many low alcohol beers were panned by beer drinkers due to poor quality and taste, but in recent years many improvements have been made in the quality and taste of low-alcohol beers making them a popular option for those who want to enjoy a beer without alcohol. These beers provide a good option for designated drivers, casual drinkers, those with health restrictions and those who choose to avoid alcohol for other reasons.
Methods for Making Low Alcohol Beer
Here are the top level methods for making low alcohol beer. Note there are a lot of variations possible and in some cases multiple methods are applied to achieve the desired result:
- Boil Off or Distillation (Vacuum): Brew and ferment a beer that contains alcohol, and then boil off the alcohol while leaving the beer. Alcohol boils off at a around 173 F (78.3 C) so you can boil the alcohol off without boiling off the water in the beer. Commercially this is often done under a vacuum which lowers the boiling point further. The downside of this method is that heating the beer changes the taste of it, often in negative ways. Also the alcohol and water bond into azeotrope which is difficult to separate by boiling alone.
- Low Starting Gravity with Low Fermentability: You can start with a small grain bill, and then use either very high mash temperatures or a cold mash (steep) to create a wort that is low gravity but also has few fermentables. This can result in very little fermentation though it can be difficult to properly balance flavor of the finished beer.
- Yeast Selection or Arrested Fermentation: There are some new low-alcohol yeast strains which do a great job of fermenting malt while producing very low levels of ethanol (alcohol). Using these yeast strains you can start with a slightly low gravity wort and end up with a well balanced beer that still has low alcohol. I’ve tasted some commercial examples made with these yeasts that were surprisingly good. Similarly you can halt a normal fermentation prematurely to achieve a similar effect using sulfites/sorbates (or similar chemicals).
- Reverse Osmosis, Membrane Filtering and Centrifuge Separation: Though hard to do at home, you can use osmosis, a filter, or centrifuge to separate the alcohol out in a finished beer. This method can produce zero alcohol beers as well as low alcohol beers from a normal finished beer.
In part 2, I’m going to discuss several of the methods above and how they can be applied to homebrewing.
General Principles for Low Alcohol Beers
Before I go into detail on the methods above (part 2), I wanted to discuss some general principles for formulating low alcohol beers. Because of the low alcohol levels these beers do require a slightly different approach than a traditional beer.
Achieving Mouthfeel and Body – The first principle that I wanted to discuss is achieving the proper mouthfeel and body in the beer. Because a low alcohol beer has a low starting and finishing gravity, many of these beers taste “thin” in body with little or no malt character. To counteract this you do need to formulate your malt bill to have specialty malts that add malt character and body to the beer. For a lighter beer this might include adding adjuncts like Carafoam, very light crystal/caramel malts or lightly colored kilned malts like Munich, Vienna or even a bit of amber or biscuit malt.
For darker beers, you can add roasted malts, but you should make an effort to avoid tannic and harsh zone malts as the tannins or harshness often has no counterpoint to balance a low alcohol beer. Another trick is to use adjuncts that may not be as fermentable or even steep malts without mashing them which will leave more unfermented starches in the finished beer.
Work with a Low Starting Gravity – No matter what method you choose to reduce the alcohol, most of these beers start with a low starting gravity. If you are working with a special low alcohol yeast, you want to keep the gravity low to avoid too much alcohol byproduct. If you are boiling or distilling the alcohol off you want to minimize the beer’s exposure to heat by again keeping the starting alcohol low. The same is true for other methods.
Balance Hops and Malt – Because your low alcohol beer will in general have a lower starting and finishing gravity, care must also be taken to maintain a proper malt-hop balance. The bitterness ratio is a very good method to achieve the proper balance. For a given style of beer, take a look at a few sample beers from the style and calculate the bitterness ratio (link here explains how). Then try to achieve roughly the same bitterness ratio using your low estimated starting/ending gravity for your low alcohol beer.
That’s a quick overview of low alcohol and non alcohol beer brewing. Next week in part 2 I’ll present some of the methods above in more detail that are practical for a typical homebrewer. And in Part 3 I’ll cover additional methods as well as finishing your beer. Please subscribe for regular weekly delivery, check out the podcast, and don’t hesitate to retweet, link, like or mention any of my articles on social media.
