Fermenting with Bourborn Barrels
Moonshine provided a ready source of cash and barter for many Kentucky farmers in the 1800s. Country stills yielded a clear and harsh liquor that was stored in oak barrels. The insides of the barrels were intentionally blackened by fire. The barrels traveled by rickety wagons over pot-holed roads to the steamships in Louisville, Kentucky. From Louisville, the steamship took days to traverse the Ohio and Mississippi Rivers. The long river journey subjected the barrels to constant rocking. By the time the barrels reached New Orleans, an amazing transformation had taken place — the liquor had turned amber and sweet. The raw moonshine had become Kentucky bourbon.
Origin of Bourbon
The Scots and Irish settlers of Kentucky arrived with strong whiskey- making traditions. The farmers used corn as the primary ingredient in their mash since it grew so well in this humid region. Oak trees also grew well in the region’s forests and the wood was relatively easy to shape into barrel staves. Barrels were often reused. One method of cleaning was to burn the inside.
Modern Bourbon
To be considered “bourbon,” the whisky must have at least 51% corn in the mash, be aged a minimum of two years in new charred oak barrels, have no color or flavor additives and must be made in Kentucky (according to a 1964 Congressional decree). Whisky may be made elsewhere, but it cannot be called bourbon.
Bourbon Barrels
Bourbon barrels are constructed with 30 to 35 white oak staves held in place by metal hoops. White oak has a unique sweet smell that is detectable in freshly split wood. White oak trees (with rounded leaves) differ from the more bitter red oak trees (with pointed leaves). Bourbon barrels typically have a moderate to heavy amount of charring, compared to the lighter toasting used for wine. The standard barrel size is 53 gallons, which weighs in empty at 100 pounds and 540 pounds full.
Let’s take a look at a used bourbon-barrel stave to see what happens to the wood in the barrel. The innermost layer (1/32 inch) is black from charring. The next layer (1/2 inch) is wet from the bourbon seeping into the wood. The depth of the bourbon is naturally marked with a red line in the wood. The remaining 1/2 inch is not in contact with the bourbon except by evaporation.
Within the wood of a fresh bourbon barrel, there is probably one gallon of bourbon trapped in the wet layer of wood. The bourbon in the pores of the wood makes the barrel a ready-to-use fermenting vessel.
Bourbon barrels acquire a complex taste of vanilla, caramel, oak and spices after being saturated with bourbon. The unique character of used bourbon barrels has been prized by Scotch and Canadian whiskey producers for years. Several American craftbrewers have also used bourbon barrels to create-award winning beers. Some commercial examples of bourbon-barrel beers are Big Bad Bourbon Brown (Big Horn Brewing, Indianapolis), Bourbon County Imperial Stout (Goose Island, Chicago) and Pipkin Bourbon Barrel Stout (Pipkin Brewing, Louisville).
Brewing with Bourbon Barrels
The first step in bourbon-barrel homebrewing is to obtain a tight bourbon barrel. The barrel may be slightly warped but should still be watertight. If you don’t live near a distillery, barrels may be shipped by UPS for $50 to $60. After you get your barrel, remove the wooden bung. This may require a pocket knife to extract. After removing the bung, smell the barrel. It should have a strong bourbon smell, since emptied barrels often have a gallon of bourbon soaked into the wood. If the barrel doesn’t smell good, don’t use it!
Find a stable place to put the barrel. Remember that it will not be possible to move a full barrel without a forklift, since it will weigh over 500 pounds. A simple storage system consists of a sturdy wooden pallet with 4″ by 4″ boards on each side of the barrel to prevent it from rolling. Keep the barrel out of sunlight and away from gasoline or other products that emit vapors that you don’t want in your beer.
Now the fun part — making 53 gallons of beer! This may require multiple batches or enlisting a whole homebrew club. Stronger types of beer (with original gravities of 1.060 or higher), such as stouts and barleywines, go well with the bourbon flavor.
The beer should go through an initial fermentation for 5 to 7 days. After primary fermentation is complete, rack the beer into the barrel. (A food-grade pump is useful to move this amount of beer into and out of the barrel.) Be sure to fill the barrel as full as possible to prevent oxidation and discourage the formation of vinegar bacteria that requires air. Replace the old bung with a sanitized #11 stopper or a drilled #11 stopper with an airlock.
The recommended barrel fermenting time is 30 to 100 days – a shorter time for lower-gravity beers and longer for stronger beers. The progress of the bourbon character may be tested with a sanitized wine thief or a straight piece of racking cane.
After aging, rack or pump the beer into bottles or kegs. Fresh yeast should be added if the beer is bottle-conditioned, along with priming sugar. Forced carbonation is required if you keg. Most commercial brewers recommend using the barrel only once, due to the possibility of contamination after the initial bourbon is gone. The barrel can be used as a stand-up bar or cut into two planters.
Bourbon Barrel Char
Attached to the charred insides of the barrel are flakes and splinters of wood, which are crystallized oak sugars. After years in the barrel, much of the charred wood breaks loose inside the barrel. The resulting chips of wood are called “char.” The chips are 1/4- to 1/2-inch pieces of charcoal that smell and taste like bourbon. The char has been sanitized by fire and bourbon.
Secondary fermentation with the char from bourbon barrels offers another option for homebrewers that want a bourbon barrel effect but do not or cannot use a whole bourbon barrel. The size of the chips allows homebrewers to add them to any type of container, including the narrowest of carboy necks. A mild impact from char occurs with 1/2 cup of char per gallon. A strong effect occurs with 1-1/2 cups of char per gallon. Strength is also determined by the amount of time that the char is left in the fermenter — even two weeks will add to the flavor.
Char is easy to use since it has been sanitized for several years in the barrel. If handled properly, char may be added directly to the secondary fermenter. Initially some of the char floats, but eventually it settles out with the yeast and other fermentation particles. Racking the liquid off of the char is easy with a tip on a racking cane. Char may also be placed in a sanitized nylon bag to make removal easier.
Fermenting Wine in Bourbon Barrels
Fruit wines, meads and ciders are also improved by bourbon-barrel fermenting. The charcoal filters harsh tastes, such as fusel alcohol. High-alcohol fruit wines, such as cherry or raisin jack, are great candidates for bourbon-barrel treatment. The mellowing effect of char or a bourbon barrel accelerates the aging process.
Bourbon Barrel Cider Project
Several members of the Louisville Area Grain and Extract Research Society (LAGERS) met at a friend’s barn in early September. Eight of us had collected bushels and bushels of apples and pears for the big pressing. Our friend generously offered his commercial grinder and presses to process the bumper crop of fruit.
We spent most of the day cutting out bad spots in the fruit and filling containers with fresh juice. By the end of the day we had 80 gallons of juice and the cows had plenty of dry pommace. Using a recipe from a master distiller, we later filled two freshly emptied bourbon barrels with cider and perry that had gone through a primary fermentation. We then dissolved cane sugar to reach an ending gravity of 1.030. After anxiously waiting for one year we emptied the barrels. We were all delighted by the intense fruitiness, vanilla and spice character of the barrel-aged cider and perry.
