referred to as ‘maturation’ and usually
involves the aging in a wooden barrel.
Beer fermentation in wood has existed
for centuries as part of the Belgian
tradition and culture.
A barrel is a hollow container made
of wooden staves and bound by wood
or metal hoops. In taking up wooden
barrels, brewers are reverting to
traditional technology that was a part
of the craft for centuries. The wooden
barrel was well established in European
culture. The art of barrel aging involves
something much more than simply
pouring the brew into a wooden
container. Research on beer describes
that beer ageing in wooden barrels
is a complex way of adding a special
aroma to beer and maturate it. The
wide range of chemical processes act as
enhancers during ageing. Basically the
process is called ‘micro oxygenation.’
In this process, the barrels are never
completely sealed, a step that facilitates
continuous oxygen transfer through
the casks and changes the taste of
substances in the beer. During the aging
of beer in a barrel, the beer absorbs the
various chemical compounds present in
the wood, such as lactones (lactones
provide floral aromas to beer), phenolic
aldehydes (which provide vanilla), and
the simple sugars (for caramel flavours).
Beer ageing reveals the actual sensory
changes during beer storage in barrels.
Aging shows a constant decrease in
bitterness of the beer because of the
masking by an increasing sweet taste.
This initial acceleration of sweet aroma
development during ageing is due
to the formation of caramel of sugar
fermentation in barrels. During the
ageing in wooden barrels, oxidation
of the stored content takes place,
due to the oxidation astringent, the
flavour of beer decreases and its
colour, stability and flavour increases.
Complex chemical compounds of the
barrels contribute to the development
of the flavour. These complex chemical
components of the barrel woods are
basically volatile phenols containing
vanillin which provide a sweet
Fermented beverages can be
divided into two groups, wines
and beers. Wines are fermented
from various fruit juices containing
fermentable sugars
Drink Asia
37
July-August 2019
and pleasant aroma, carbohydrate
degraded products like furfuls which
provide a sweet taste, lactones provide
woody aromas, terpenes provide
tabacco shades, some phenols like
tannins provide bitter flavours in beer
maturation or aging in barrel.
Barrels were first used for wine by the
Romans. The big advantage of barrel
aging of beer is the oxidation, which
slowly provides the oxygen to the beer
(air incorporation occurs due the pores
at the surface of barrel wood), while
it also provides colour from oxidation
of tannins of the wood of barrel. Beer
absorbs lots of aromatic components
during ‘maturation.’ Barrel ageing is
not only the best treatment of beer
maturation but also provides a strong
and dark flavour to it. Nowadays barrel
aging is becoming a global trend of beer
maturation.