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
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
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.
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
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
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.
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
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
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.