Oak's Balancing Act06/10/2008
Originally appeared in Zymurgy May/June 2008
Oak has been used in brewing for many years, but recently it has seen a resurgence of interest due to its large flavor impact on both wine and beer. In the past, the oak flavors gained from storage in wood were considered to be a secondary benefit. Now, with the popularity of stainless steel fermenters and storage tanks, brewers and vintners alike are able to use these flavors as a creative addition to their products.
When used properly, oak can lend the most beautiful, full and rich properties of the wood and weave them delicately into the beer. When used improperly, oak can destroy the balance that you have worked so hard to achieve, and can taste like you are chewing on tree bark. A little knowledge on what oak is all about can be the difference between turning a good beer into an award-winner or lawn food.
What exactly happens when you put oak in beer?
For example, American oak at a light toast level will lend a fresh wood and coconut character to your beers, but as toast levels increase to medium/medium-plus levels, these flavors are decreased and more vanilla and caramel notes are brought forward. Medium-plus is typically the best of all worlds in dealing with toast levels, as it brings out the qualities you would normally find in a heavier toast, without diminishing the vanilla and other ?softer? qualities found in a lighter toast. There are many different oak delivery methods, including aging your beer in a full-size barrel, and using sawdust or barrel replica kits. Oak chips and oak cubes are the simplest for homebrewers to use. A barrel is not feasible for many homebrewers, as they require a lot of hard work tokeep them in good working order (clean, stored properly and bacteria-free). Sawdust can be hard to work with and will take some extra time to drop out in your beer, not to mention its lack of complex flavors. Staves and other barrel replica kits are geared more for use with large barrels that have lost much of their oak impact, and are often too large to be used easily in carboys. Chips and cubes, however, are very ?user friendly? and do not need any sort of extra attention or care like their larger counterparts do.
Oak Chips and Oak Cubes
Many homebrewers have not experimented with oak, mainly due to one fear-sanitizing! ?How should I sanitize this stuff? Do I soak them in sanitizing liquid, boil them in water?? Sanitizers should not be used, as the sanitizer will be absorbed by the wood and carried over into your beer.
A simple way is to steam the wood, killing anything that may be living inside. One method is to put the wood in a Pyrex measuring cup with just enough water to cover the wood. Cover the top with a saucer and heat it in the microwave until the water starts to boil. Turn the microwave off and let the wood steam for two minutes. Repeat the process twice. This should kill anything that may be living in the wood. Add the oak and the water left behind to the keg, as the water will have a nice oak essence to it. If you plan on soaking your oak in alcohol, such as whiskey, this is all the sanitizing you will need as the high percentage of alcohol will kill anything that may be living in the wood. Kegs are the best container to store your beer while it is aging on oak. You can carbonate it at the same time, and it is much easier to pull samples than from a carboy. Once the beer has been racked into the keg, it is time to add the cubes. Eventually the cubes will end up sinking to the bottom of the keg, and because this is also where the dip tube will be pulling your samples from, you will no doubt taste a very unbalanced beer. Every three weeks or so, rock the keg gently back and forth to ensure the portion of the beer that is in contact with the oak gets properly mixed with the beer toward the top of the keg.
If you are interested in trying your hand at a bourbon-aged oak flavor, try soaking your cubes for two weeks in a few ounces of bourbon or whiskey, and discard the whiskey before adding the oak to your beer (I find Wild Turkey blends well with darker beers). It is very easy to overdo the addition of bourbons or whiskeys, and less is definitely more which is why I prefer letting the cubes ?dose? the beer over time. The oak should be up front, with the booze layered softly under the malt. If the flavor is not pronounced enough after two months of being on the oak, adding bourbon straight to the keg is acceptable, but be careful not to overuse it. Tasting the beer over the next few months is a great way to see how the flavors and oak compounds blend and merge into your beer. After the first week on the oak, you will begin to taste hints of different flavors, but I find that they really start to meld after about four to six months. The longer you leave your beer in contact with the wood, the more of these great compounds will become infused with your beer. The cubes will continue to add flavor up to about a year. A great way to get that deep, complex oak characteristic is to use a one-two punch of chips in the fermenter and cubes in the keg. Adding oak chips to the fermenter will allow the beer to absorb some of those basic oak flavors we are looking for,
and gives the cubes a nice foundation to build on when they are added to the beer after fermentation. Half an ounce of chips per 5 gallons of wort is a nice place to start. You may find some beers need less, and some need more. Feel free to experiment and find a starting point that bestsuits you. The best part about oak is that it complements almost any beer!
Making beer and using oak are very similar: they are both easy to do, yet the best results require a subtle hand that is achieved only by repetition. If your first wood-aged beer does not turn out right, try again, maybe with less oak, or a different toast level-or perhaps a different varietal altogether. Maybe a blend of American chips and French cubes is the answer for your porter-who knows? Above all else, be patient. The world of oak awaits!
Jason would like to thank Shea A.J. Comfort from yeastwhisperer.com for his technical information on oak.
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