Why Add Fruit to Beer

Since the dawn of time, humans have been adding fruit to beer. In Babylonia and Egypt they already used dates in the ferment. Today we still draw from the Belgian tradition, world‑renowned for the use of adjuncts in its beers, especially fruit. Belgium’s beer culture has served as an inspiration for the craft beer movement in its quest for new sensations beyond the four basic ingredients.

Historically, the reason for adding fruit to beer is that in practice it boosts the must’s fermentative capacity—but why? On the one hand, fruit is coated in yeasts, bacteria and fungi on its surface, which makes fermentation almost guaranteed—although it doesn’t always match the organoleptic profile we’re aiming for! On the other hand, ripe fruit is a natural source of sugar, which provides more food for microorganisms to turn into alcohol and CO2.

Precisely because of their high fermentative capacity, we must be especially careful when adding fruit to our brews. If possible, we should remove the peel whenever we can to eliminate unwanted contamination. If we want to use citrus peel, for example, we can sterilize it by macerating it beforehand in a spirit (vodka, gin, etc.). There are also fruits such as strawberries, raspberries and other berries where it’s impossible to separate the peel. In these cases, we opt for prolonged freezing of the fruit, although there are safer options.

Some suppliers offer fruit pulp, purée, and juice that are already sterilized, which helps us avoid contamination risks. However, some brewers intentionally seek out these contaminations in a controlled way to give the beer different fermentation profiles. Most likely, you’ll get a sour beer if you allow wild microorganisms to ferment your wort; that’s in the best-case scenario—otherwise you’ll have to throw the beer away.

For this reason, some brewers add the fruit directly during the mash (pumpkin in pumpkin ales); also during the boil, although it’s best to add it in the final stages to pasteurize the fruit while preserving its aromas and flavors. This way, the heat should eliminate most harmful microorganisms. There is also the option of adding the fruit in secondary fermentation, because by then we already have a certain alcohol content and a low pH that inhibits harmful microorganisms. When adding the fruit, we can use a bag to remove the remains afterwards.

In any case, this does not free us from an extra load of sugars. What does that mean? You must be especially careful with fermentation, as it is difficult to estimate the beer’s final alcohol content. You must wait for fermentation to finish. Otherwise, if you rush to package, your bottles may explode due to uncontrolled refermentation. Adding fruit is a risk for both home and professional brewers. However, it can provide spectacular aromas and flavours. Are you up for brewing your first fruit beer? Always with caution!