Beer and wood
Part 1
Greetings from Asterix
The use of wooden vessels at various stages of brewing is not a recent innovation. The first records of wooden vessels made of staves bound together with hoops date back to Ancient Egypt around the 26th century BC. However, the Romans attributed the invention of the barrel to the Celts around the 3rd century BC. At that time, the Celts called themselves Gauls and inhabited almost all of central and western Europe, except the Mediterranean coast. The Celts used barrels for their favorite drinks – beer and mead. This period is generally considered the beginning of the wooden barrel era; for the next 2,000 years, wooden barrels of various sizes were the main storage and transport method for almost any beverage, as well as a range of other food and non-food products.
It all started when the Romans began growing grapes for wine in newly conquered Gaul for their garrisons. Soon, the wine grown in Gaul gained popularity in Rome, where it was transported in an innovative container – the wooden barrel. Seeing the advantages of the barrel over the previously used clay amphorae, the Romans adopted the barrel as a liquid transport vessel throughout the empire within a few decades.
Millennia of the Barrel
Starting with Ancient Rome, coopers rolled out barrels of various sizes from their workshops for centuries. These ranged from small, few-liter kegs used to take beer to the fields for a day’s work, to a massive 200,000-liter vat made in France in 1885, commissioned by a champagne producer.
The Great London Beer Flood which occurred in October 1814, also started with a slipped hoop from a nearly 7-meter-tall wooden vat where premium porter was conditioning. This mishap resulted in a wave of 600,000 to 1,500,000 liters of beer that destroyed the brewery wall and killed seven local residents.
Bavarian brewers who tormented yeast at low temperatures in their ice cellars; the original IPAs the British shipped to India for their thirsty officers; the Russian Imperial Stout brewed in England for the Russian Imperial Court since the time of Peter I; or any home-brewed Latvian beer, mead, or mixed-source brew (miestiņš) – absolutely all beer until the mid-19th century spent its entire production period in contact with wood. Primary fermentation took place in more or less open wooden vats, after which the beer was moved for maturation into barrels of various sizes and then packaged into smaller casks, depending on the end user’s needs.
Happy Accidents
Oak is best suited for this purpose – it has dense wood that makes the barrel liquid-tight, it is flexible enough to give the staves their characteristic curved shape, and it is sturdy enough to withstand the stresses of transport. Additionally, oak was plentiful in Europe, the birthplace of barrels.
To bend oak staves into the required barrel shape, they must be subjected to heat. Most likely, this led to early experiments with the intensity and duration of the flame, which, as it turned out, causes the tannins in the wood to soften, the sugars to caramelize, and the vanillin to release, making the beverage softer on the palate after contact with the wood. For this reason, barrel ageing is particularly popular for more expensive wines, as well as for cognacs, bourbons, whiskies and rums from different regions.
Unfortunately, this effect does not last forever, and the longer the barrel has been filled, the less it is able to soften the beverage. However, this is not a major issue, as other beverage producers may require different characteristics from the barrel.
The Life of a Barrel
Generally, in the world of alcoholic beverages, barrels are somewhat nomadic. They host one drink for a few years, then move on to another.
For example, the legal definition of bourbon states that the barrel must be virgin – only a corn spirit aged in a new, internally charred oak barrel can be called bourbon. Because of this, bourbon barrels are among the most readily available on the market. Until recently, they were mostly reused for a second time by thrifty Scots, who aged their barley whiskey in these same ex-bourbon barrels for several more years or even decades, extracting every last bit of goodness from the wood.
The barrel’s adventures do not end there, however – they are often subsequently used for the experimental aging of rum, tequila, beer, or even hot sauces. In this case, the maturation of the beverage in the cask will give it the characteristic flavour and aroma nuances of the previous cask visitor. This is exactly why Imperial Stouts are often aged in various whiskey barrels, imparting the highly complementary whiskey notes to this beer style.
The journey of the barrels used to age our stout, Lielais Kristaps, is quite classic in this regard. It all started in the USA, where barrels made from American oak were charred and filled with corn spirit, which left the barrel after three or more years as bourbon. Afterward, these barrels made their way to Fiji, where they were used for an experimental rum made from sugarcane and infused with tropical herbs before being laid down in the casks.
Only then did the barrels reach us, where they were filled with our stout. To compensate for the vanillin extracted from the barrel by the bourbon and rum, we added vanilla pods for an extra smooth and silky result. Before bottling, the beer from several barrels was blended in a stainless steel tank and gently carbonated. This brings us to the second important characteristic of a cask – the ability to let the drink breathe. But more on that next time.
Time to taste our Barrel-Aging beers!
