Case Study - Sustainable Use of Casks

31 May 2012

Our Commitment: We will seek to ensure that in future all casks brought into the industry are made from oak sourced from sustainable forests.

Scotch Whisky must by law be made in Scotland and matured in oak casks for at least three years. Casks play a pivotal role in maturation, imparting flavour and a golden colour to the whisky.

Casks will have already been used and emptied before being filled with spirit for Scotch Whisky maturation. Casks are then re-used three or four times until they are no longer serviceable, a working life of several decades. Forests supplying this oak must be operated sustainability to ensure supplies and improve the environment.

Sadly, oak forests have historically suffered from over exploitation for a variety of uses. Nowadays, however, oak forests are expanding. The market for oak, including cask manufacture, is an incentive to properly manage these resources.

Bourbon casks

90% of the casks used in Scotland were originally employed in the maturation of Bourbon. These casks are sourced from the white oak forests of the US Mid-West states. Whilst white oak regenerates naturally, either from acorns or stump sprouts, forests need to be managed by regular thinning to optimise the white oaks growing conditions.

These are dynamic ecosystems and continued demand for wood perpetuates a healthy forest and greater diversity of plant and animal life. Growth can take up to a century and careful harvesting to allow a net growth of timber is key to effective and sustainable forest management.

The Glenmorangie distillery, located near Tain, sources casks from the Blue Grass Cooperage in Kentucky, which hand selects oak trees to meet the company's specifications. Lumbering operations in the Ozarks of Missouri are supervised by the State Conservation Department. The US Forest Service in Missouri reports the rate of oak wood volume growth is far greater than the rate of harvest, with the volume of standing wood increasing. Indeed, the Mid-west forests are aging, and in some areas the lack of young forest is limiting to wildlife diversity. Most US States have voluntary Best Management Guidelines for logging, which are designed to protect soil and water resources during logging operations.

Sherry casks

Many whiskies obtain their unique flavour from the use of sherry casks, sourced from the European Oak forests of Northern Spain. Scotch Whisky producers are often the first buyer of these casks and allow Sherry producers to use them
for a period of time before they are sent to Scotland.

The Edrington Group, distillers of brands such as The Macallan and Highland Park, wanted to ensure the sustainability of its oak sources in Spain. To this end, they commissioned the University of Vigo to study the oak forests of Galicia, Asturias and Cantabria.

The study concluded that the source oak forests are being sustainably managed. An annual increment of growth of 655,000 cubic metres and an annual harvest of 150,000 cubic metres (a proportion of which becomes casks) resulted
in a net annual increase of 500,000 cubic metres in wood production. Over a ten year period studied the European oak timber stock increased by 67% providing a sink for carbon dioxide and valuable broad-leaf deciduous forests, vital for
maintaining biodiversity.

What do we do in Scotland?

Cask making traditions are still maintained in several distilleries and cooperages across Scotland, which both make and repair oak casks. Each cask has a working life of over twenty years and when no longer required or serviceable
the casks are sold for a range of uses such as for garden ornaments, furniture or fuel.

The Macallan has, for example, raised customer awareness of the importance of a sustainable source for casks by linking certain brands with tree planting on its own estate. A limited edition of 'Woodland Estate', matured in ex-Sherry casks,
enabled consumers to own an oak tree identified by a plaque bearing their name and the number of the bottle. Many owners have taken the opportunity to visit their trees.

Launching an 'Estate Oak' brand, the company committed to planting an oak tree on its Speyside estate for every bottle purchased. The bottle label is made of recycled paper and certified by the Forest Stewardship Council. Eventually over
125,000 trees of different types will be planted to screen the distillery and improve wildlife diversity.