The importance of ethanol in making good non alcoholic beer
March 2024
Ironically, understanding the contribution of ethanol to beer is one of the key differentiators in making high quality non alcoholic (NA) beer. Ethanol is fundamental to beer with many interactions that are critical to a beer’s flavor and aroma, including flavor extraction, flavor perception, off-flavor masking, flavor solubility, and aroma retention. Ensuring that an NA beer tastes like a full-strength one requires understanding and compensating for these effects. The brewing process, approach to creating an NA, and post-process additives can all have a strong impact on a brewer’s ability to achieve this compensation. In this article I’ll discuss some examples at each stage of the NA production process that can help to compensate for the lack of ethanol in NA beverages.
Compensating for the importance of ethanol starts at the very beginning of the NA production process with the selection of raw materials. For example, certain hop varietals have more water-insoluble flavor compounds than others. With these hops, ethanol’s importance applies double. First, the ethanol is necessary to extract these flavor compounds from the hops, since they aren’t soluble in water and second, the ethanol helps to retain these compounds in the beer at higher levels. If halted fermentation or maltose-negative yeast is used for the production of the NA, you lose some of your ability to extract these water-insoluble hop compounds and keep them in solution. Another example where this same effect will apply is in barrel-aging. Much of the complexity of barrel-aging comes through from water-insoluble compounds that are extracted from the barrels during this process. This extraction will not readily occur without ethanol. Production methods where full fermentation occurs such as thermal or reverse osmosis based dealcoholization allow flavor extraction with ethanol from the raw materials, but once the ethanol is removed keeping these flavors soluble above the perception thresholds can be challenging in some cases. The flavors, once ethanol is removed, can stay above the perception naturally in some beers like hazy IPAs, with the particulate in the beer holding these compounds, or can be bolstered by adding solvents which these compounds are soluble in like propylene glycol or glycerine. Alternatively, choosing raw materials where the primary flavor compounds are soluble in water can resolve these issues for all production methods.
The brewing process is the next factor in the production that can be used to compensate for the lack of ethanol. Ethanol removal results in increased perception of bitterness and reduced perception of body. One way to compensate for both of these changes is to increase the mash temperature so that you have more unfermentable sugars in the beer. These unfermentable sugars add sweetness which lowers the perception of bitterness and the unfermentable sugars also add more body to the beer. The brewing process is also very important with how off-flavors are perceived in the final process. Ethanol has a masking effect for many off-flavors such as a worty flavor. Even more so than with brewing full-strength beer, brewing high-quality NA beer relies on the skill of the brewer to minimize off-flavors through brewing best-practices. This is particularly true for styles where low levels of certain off-flavors are acceptable like with diacetyl in pilsners. Given that this is an area where brewing skill is particularly important, the brewing process can be a strong differentiator for a brewery’s NA beer and offers the opportunity to achieve higher product uptake.
As I touched on above when discussing raw materials, the NA production process strongly influences the ability to compensate for the lack of ethanol in NA beer. For example, with halted fermentation the biotransformation of intermediate products cannot occur and this can lead to worty flavors being emphasized. Maltose-negative yeast helps to achieve biotransformation without ethanol as a byproduct, but since the maltose-negative yeast only ferments the simplest sugars, flavors associated with the remaining more complex sugars may be emphasized relative to fully fermented beer. Reverse osmosis and thermal dealcoholization both act on fully fermented beverages and therefore start with the closest input to finished beer, so how effective they are at retaining the flavor and other properties of the full-strength beer depends on how effectively the flavor compounds can be kept in the low-alcohol portion of the dealcoholization product. Reverse osmosis is size-based and so will tend to lose flavor compounds that are similar in size to ethanol or smaller. In contrast, thermal dealcoholization primarily loses compounds that have lower boiling points than ethanol. That being said, thermal dealcoholization is ideal for flavor retention, because the system can be designed to separate multiple components easily. With this strategy these aroma compounds are removed ahead of ethanol removal and recombined into the NA. In this case, the primary loss is due to components that are insoluble in water staying in the higher ethanol output. This can be mitigated via either beer composition or additives as was discussed in the materials section.
The final critical step to compensating for the lack of ethanol in NA beer is using post-process additives. The water-soluble hop oils that have been entering the market recently are a particularly powerful example of additives that can compensate for the lack of ethanol. As discussed above in the materials section, components that are water insoluble such as standard hop oils are one of the flavor categories that are the hardest to compensate for via the brewing or NA production process. The water-soluble hop oils represent a way to return many of these compounds to an NA during the finishing process. Other additives can have a similar ability to bring back flavors that my be difficult to maintain through the brewing and production process.
Overall, there are many strategies that can be used to compensate for the lack of ethanol in NA beverages and interlocking these strategies through a thoughtful process ahead of creating an NA can lead to the best outcomes. High-quality NA beer even more than full-strength beer emphasizes brewing skill and provides the opportunity to differentiate your brewery from both a quality and a product perspective. As the NA market continues to grow the methods to compensate for the lack of ethanol have grown with it and staying current with the state of the art is important. This article represents a very brief look into the various facets of compensating for the lack of ethanol in NA beer and indeed an entire book could be devoted to this topic. At ABV Technology we are constantly innovating in this area and can help support your NA production process with this technical expertise in addition to dealcoholizing your beer.