Written by Justin Stewart, Brewer
Ever since the wooden barrel was invented beer was destined to be put into it. It has been used to transport the liquid substance since well before the Victorian Era England. Whether knowing it or not, the beer within the barrels also took on a slight flavor characteristic of the container. Contributing along with the hardness of the water of the region, history also suggests that this pointed to the staple styles of porters and stouts that could hold up to this flavor pickup that England is known for. It is a relatively new phenomenon however to put beer specifically into a barrel for flavor pickup. There are many methods and reasons for doing this and as experimentation shows, no technical wrong way.
One of the widest known reasons for barrel aging beer is to add a fortified warmth flavor. These are the whiskey and bourbon barrel aged beers. Although not exclusively, the beer put into these types of barrels are ones that with a hearty malt backbone that can stand up to and compliment from the robust flavor that has been imparted within these barrels. Base beers for this method would include porters and stouts. The beer that is put into these barrels extracts the flavor the same way that the barrel itself did with the spirit. The wood of the barrel contains many pores, and throughout the day as the temperature increases the liquid saturates into the pores of the barrel and as the temperature cools it is returned to the interior of the barrel along with other liquid flavors that have similarly done this and of course a wood flavor. There is an optimal temperature for this, and optimal times to extract both the desired amount of whiskey and wood flavor. And of course the barrel itself has a tremendous impact on this. If the barrel is received ‘dry’ or with minimal spirit in it, it will take longer to get the flavor desired. Along similar lines, if the barrel has been used multiple times it will take much longer to get a perceived whiskey flavor if at all as each beer before it has absorbed a little bit of what was in the barrel. Longer aging times are thusly not always better, as the beer can risk a potential problem of picking up too much of a wood flavor from the barrel. If I wanted that I would eat whiskey soaked chips thank you. What those aren’t edible?
Using the whiskey and bourbon barrel aging as a guideline, some variables can now be changed for creative results. There are just as much spirits as there are beer styles, and the surface has just been scratched with the combinations therein. A white ale in a gin barrel? An IPA aged in tequila? Red ale in a red wine barrel? Forget space, exploring these combinations is the final frontier.
If barrels are not available there are other methods for replicating this process. A variety of chips from different types of woods and that may have soaked in different spirits are being made. The advantages of this is that exotic types of wood that aren’t normally found in barrel form can be utilized, such as birch or white ash to add very distinct flavors. Another advantage is that due to the surface area and contact of the chips on the beer the amount of time needed to receive the desired flavor is dramatically reduced. Studies do contrast however that if the chip method gives a true barrel character and flavor to the beer however.
But alright, a barrel has been used multiple times and no more spirit flavor can be extracted, time to roll them downhill into unsuspecting presidential rallies? No, at least not yet. Barrels in this status can also be used more as a holding vessel and an incubator for sour beers. Many sour beers are delicate and would not benefit from a fortified alcohol flavor conveniently enough also. Sour beer also requires both time and a step fermentation that are ideal to have in barrels. The oxygen ingress helps the wild yeast ferment and take on its special flavor, and not only does having it in barrels reduce the storage of having it in a fermentation vessel, it segregates it from your other products to help ensure that they don’t sour themselves.