Methods for NA Beer Production
In my mind there are a couple of things that make beer, beer. The number one thing that defines beer is malt, and more specifically malted barley. Aside from the occasional malted milk shake or Malta soft drink (which is really just unfermented beer), beer and malted barley are synonymous. Hops get a lot of publicity, but hops can be found in a wide range of products now; hop water, hopped tea, hopped kombucha, hop soap, and the list continues to grow. Malt is the magic of beer, it is what gives it an infinite range of color and flavor, and what makes it the absolute best beverage to pair with food. Ok, you get the idea, I better move on before this turns into a post all about malt.
The other major defining characteristic of beer is the fermentation process. Fermentation in essence is a biological process by which a microorganism metabolizes sugar and creates byproducts. In the case of beer, yeast (and sometimes bacteria) consume sugars and produce ethanol, carbon dioxide, and other byproducts such as esters. These “other” byproducts can be detrimental to or beneficial to the final product, and they can be subtle or rather pronounced such as in our Belgian-style beers and saisons.
So there in lies the predicament and the challenge of making NA beer, how do we ensure that rich, maltiness is present in the final beer and how do we get those desirable byproducts without the ethanol that is also produced during fermentation?
There are lots of different methods for producing non-alcoholic beer. As I mentioned in my previous post, most NA brewers are pretty tight-lipped about their specific methods but generally I would classify the main known methods into two categories, what I’ll call fermentation manipulation and technological processing. The goal of fermentation manipulation is to prevent the production of ethanol in the first place while technological processing removes the ethanol post fermentation.
Manipulating fermentation to limit the amount of ethanol can further be broken down into two objectives; limiting fermentability of the wort and limiting attenuation.
Fermentability refers to the amount of sugar available to the yeast to metabolize. Fewer sugars mean less food for the yeast and less ethanol produced. You can limit fermentability mainly two ways, the first by reducing the amount of malted barley used. During the mash hot water is mixed with milled malt to begin the process of converting the starches in the malt to simpler sugars that the yeast can consume. If we use less malt, then there is less starch and therefore fewer resulting sugars in the final wort.
The other way to manipulate fermentability of the wort is to extract more complex sugars and dextrins from the malt which typical beer yeast cannot consume and therefore get left behind in the final beer. We’ll talk more about how to do this in a future post.
The other path to reducing ethanol production is to limit the attenuation during fermentation, or in other words how much of the overall sugar (or dextrin) content of the wort was consumed by the yeast. This can be done by selecting yeast that are poor at consuming more complex sugars, or by halting fermentation prior to completion, what is called arrested fermentation. The primary way to halt fermentation is by lowering the temperature of the beer, causing the yeast to go dormant and then filtering out the yeast.
All these methods to manipulate fermentation have their benefits and drawbacks, and in reality, many NA brewers probably use a combination of these methods to produce their beers.
The other main method for producing NA beer is to ferment a “normal” beer and then use technology to remove the ethanol that was produced during fermentation. Again, I would identify two leading methods for removing ethanol; distillation and filtration.
Distillation is basically just like what a distillery does but instead of capturing the high proof alcohol that is evaporated off we are looking to capture the liquid, sans alcohol, that is left behind. Distillation takes advantage of the fact that the boiling point of ethanol is 173 F at sea level, meaning we can boil off the alcohol while leaving the rest of the liquid behind. At 173 F though we are also going to drive off a lot of the beer’s aroma and alter the flavor. If you put the liquid under vacuum however, the boiling point of ethanol drops all the way to 93 F and therefore can be removed more gently leaving more of the flavor and aroma intact.
The other major way to remove ethanol is through filtration utilizing membrane filters or reverse osmosis. The membranes used have such small openings they allow only the ethanol (and some water) to pass through leaving the majority of the flavor components behind.
In my opinion technological methods can produce some of the best NA beers because the source beer is fermented normally. Not only does this allow you to produce the beneficial byproducts of fermentation, but it allows for the use of any yeast or even bacteria to create a full range of styles. The main drawback to these methods though is the large capital investment needed for the technology and the supporting infrastructure needed to operate them.
Below is a table summarizing the different methods for producing NA beer as well as some of the benefits and drawbacks of each method. And keep in mind that most brewers will probably utilize several of these methods together to create the best tasting NA beer.
So, given all the different directions I could take to create my own NA beers how did I decide which methods to pursue? I drank A LOT of NA beer!