OAK MASTER® infusion closure, Balancing Act
Oak has been used in brewing for many years, but recently it has seen a resurgence of interest due to its large flavour impact on both wine and beer. In the past, the oak flavours 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 flavours 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. A little knowledge on what oak is all about can be the difference between turning a good beer into an award-winner or an unsuccessful beverage.
What exactly happens when you put Oak Master closures in Beer?
Oak is full of many flavourful and aromatic compounds and chemicals that, when added to beer, create another level of depth and complexity. Examples are furfural, which lends caramel sweetness, or eugenol, which is clove-like. Vanillin, the most recognizable flavour, tastes and smells like vanilla. Lipids, which constitute the oils, fats and waxes found in the wood, are responsible for oak lactones, which lend coconut and aromatic wood flavours. These are the basic flavours found in all types of oak, and the ones we as brewers are looking for. The important thing to think about when choosing oak for your beer is, how will these flavours interact with the flavours already present? Knowing which type of oak contributes which flavours is the key in matching beer to wood. The three most common types of oak are American, French , each with its own balance of flavour and complexity. American oak has a great aromatic sweetness along with a nice vanilla component. It provides a sweet and full mouthfeel to beer, easily paired with most malt combinations. French oak also has an aromatic sweetness as well as providing a full mouthfeel, along with cinnamon and allspice characters. It is widely praised for its sweet spice and confectionary flavour compounds (custard, butterscotch, milk chocolate). The flavour profile of oak is enhanced during the toasting process, which compounds come out in what ratios depends largely on the variety of oak and the level of toast it received, ranging from light and untoasted to dark and heavy. When the oak is toasted, the characteristics unique to that variety are brought out and defined.
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 flavours 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. A toasted oak will have varying degrees of colour, representing the level of heat penetration during the toasting process. Heat is what brings out all of the different and wonderful flavours of the wood, and different temperatures with different woods for different lengths of time develop different flavours. OAK MASTER® infusion closures replicate the complex flavours of a barrel better than chips because the oak rods are able to have multiple toast levels like a barrel would. OAK MASTER® infusion closures also have a much longer extraction time, from about 8 weeks , depending on the size of the oak rod (the beer has a lot more wood to penetrate than with a chip) and the longer extraction time enables the beer to absorb the full character of the oak.