There is something romantic and magical about barrel-aged beers. Many people are familiar with the use of barrels in viticulture and distilling, but there seems to be some misunderstanding about the use of barrels in brewing. There are two main reasons that brewers use barrels in the brewing process: fermentation and aging.
Aging is the most familiar use of barrels for most people. The concept is pretty simple and essentially just adds an extra step to the brewing process. When using a barrel for aging brewers begin a beer as normal:
- Mill malted barley and other grains,
- Steep grains in hot water (referred to as mashing)
- Draining sugar rich water(wort) into the kettle
- Boiling Wort in kettle
- Adding hops during the 60-90 minute boil at varying amounts and times for bitterness and flavor/aroma
- Cooling the boiling wort to fermentation temperature(~65 degrees)
- Moving cooled wort to a fermentation vessel and introducing yeast
- Yeast consumes sugar and creates CO2 and alcohol
At this point the beer is essentially done. It has carbonation, it has alcohol, the yeast is going into a dormant state and is going to hang out at the bottom of the fermentation vessel. There are a few more steps beyond this to polish up the beer, but for our intents and purposes, the process is over and we have beer.
When using a barrel for aging finished beer, let’s say its a big rich, roasty stout -the finished beer is then transferred into a barrel, let’s say a wet bourbon barrel. The stout is going to sit in the bourbon barrel from 1-3 months in most cases. There are 2 important things that are going on the beer during this time. The Stout is going to soak up the flavors of the bourbon left behind in the porous surface of the barrel as well as characteristics of the wood itself. The beer is also going to mellow out while in the barrel. High gravity beers can often be too harsh and sharp on the nose and palate when young. The sharp notes will round out with time and the malt flavors of roast and chocolate will begin to shine.
There are also something important things that brewers are hoping don’t happen: namely bacterial infection or an unintentional secondary fermentation by a wild/aggressive yeast strain. Bacteria and Wild Yeast can create an entire range of flavors outside of the desired scope of barrels used for aging.
At the end of the aging period the beer will be taste tested. If multiple barrels were used then each barrel will be tasted individually noting any off-flavors or signs of infection/compromise. Depending on the depth of barrel flavor desired, brewers may then brew a new batch to “blend back” into the selected barrels. The beer is then packaged/kegged and enjoyed by the lucky few who can knab a taste.
This process is the most dominant use of barrels in the current marketplace and for good reason too, it makes damn good beer. As you can see the barrel aging process adds a lot of work, risk and time to the beer making process.
There is another side of barrels in brewing though, it’s a little more mysterious and a little more funky. We will get into the funky stuff in the next edition. Until then come by and try the Kentucky Streetwalker from Naughty brewing. It is a Imperial Porter aged in bourbon barrels for a year. Super tasty and on tap now, while it lasts!