In the world of whisky production, the art of cask toasting and charring is crucial for imparting unique flavours to the spirit. Traditionally, this process involved using a naked flame to toast and char the casks, but with advancements in technology, infra-red heating systems have emerged as a more efficient and precise alternative.
Edrington, a leading premium spirits company, has adopted this innovative approach by collaborating with Excelitas Noblelight to integrate infra-red toasting into their cask regeneration process.
Edrington is renowned for its diverse portfolio of spirits, including The Macallan, Highland Park, and The Glenrothes single malt Scotch whiskies, The Famous Grouse blended Scotch, and Brugal Rum. These brands are celebrated for their distinct flavours, which are significantly influenced by the aging process in oak casks. The use of infra-red toasting is part of Edrington’s commitment to maintaining the highest quality standards in their whisky production.
Richard Russell, Cooperage Manager at Edrington, is very pleased with the new installation and said, “Quality is paramount for Edrington, and the regeneration of our refill casks is an important element in this. The infra-red system now gives us a consistent quality and cask end treatment has now become a controllable operation, which is easy to use.”
To construct a cask, staves must be bent into shape, traditionally done by arranging them around a fire. This heat not only shapes the cask but also chars and toasts the inside of the staves. Charring breaks down the oak structure, allowing the spirit to penetrate more easily and interact with the flavours produced through lignin degradation. The process creates a charcoal layer that acts as a filtration system, removing unwanted flavours like sulphur and enhancing vanillin, cacao-like flavours, and spiciness. However, the intensity of the char affects the flavour profile, with heavier chars reducing tannins and oak lactones.
The flavours imparted by toasting and charring diminish with each use of the cask. To maintain consistency and quality, casks need to be regenerated. Traditional methods using open flames can result in inconsistent finishes and pose health and safety risks. In response, Edrington turned to infra-red technology for a more controlled and efficient process.
The infra-red system installed at Edrington’s Muirhall Cooperage site uses an 80.4kW carbon medium wave oven. This oven can accommodate two cask ends at a time and is equipped with an optical pyrometer to regulate temperature. The system ensures consistent quality by automatically adjusting power to maintain the desired temperature, with a typical cycle lasting ten minutes. This precision allows for a controllable operation that is both efficient and easy to use.
Benefits of Infra-Red Toasting
Consistency and Quality: Infra-red toasting provides a consistent finish, which is crucial for maintaining the quality of whisky. Unlike traditional methods, it ensures that each cask end is toasted to the same specifications, reducing variability in the final product.
Efficiency and Cost-Effectiveness: The infra-red system is energy-efficient, with running costs of approximately 40 pence per cask end. This is achieved by using full power for only two minutes to reach the required temperature, then reducing to 50% power for the remaining eight minutes.
Health and Safety: By eliminating the need for open flames, infra-red toasting significantly improves health and safety conditions in the cooperage. This aligns with modern safety standards and reduces risks associated with traditional methods.
Infra-red heating is not limited to whisky production. It is widely used in various industrial applications, including food packaging, where it dries special coatings to ensure leak-proof packaging. Infrared systems are also employed in wine barrel production, offering precision toasting without smoke, which is particularly beneficial for winemakers seeking cleaner flavour profiles.
The integration of infra-red toasting into whisky production marks a significant advancement in the industry. By providing a consistent, efficient, and safe method for regenerating casks, Edrington is ensuring that their whiskies continue to meet the highest standards of quality. As technology continues to evolve, it will be interesting to see how other spirits producers adopt similar innovations to enhance their products.
