Food Chemistry

20.3 Spirits 933

temperature of 36◦C and then are usually dis-
tilled in simple pot stills. Parts of aromatic plants
are occasionally added to increase the aroma of
the fermenting mash. This results in rum brands
with different aromas. The quality of individual
products fluctuates greatly. Especially highly re-
garded is Jamaican rum, which is marketed in var-
ious quality grades. A general classification di-
vides them into drinking and blending types. Ex-
port rums have an alcohol content of about 76–
80% by volume (“original rum”). Rum has the
most intense aroma of all the distilled spirits en-
joyed as drinks. This is acquired only after long
aerobic aging in casks, by absorption of extracted
substances from oakwood, and by formation of
esters and other aroma constituents during aging.
Original rum contains about 80–150 mg acids per
100 ml, calculated as acetic acid. A large part oc-
curs in free form as acetic and formic acids, the
rest, along with other low molecular weight fatty
acids, is esterified. The ester content and compo-
sition are of utmost importance for the assessment
of aroma quality.

20.3.2.3.6 Arrack

Arrack is made from rice, sugar cane molasses,
or sugar-containing plant juices (primarily from
sweet coconut palm extract or its bloom spadix)
by fermentation and subsequent distillation.
Dates are used for the same purpose in the
Middle East.
Countries which produce arrack are Indonesia
(Java), Sri Lanka, India (Malabar coast) and Thai-
land. Well-known brands are Batavia and Goa ar-
racks. In comparison to rum, arrack is not avail-
able in very many varieties. It is imported as the
“original arrack” with an alcohol content of 56–
60% by volume, from which “true arrack” is ob-
tained by dilution with water to 38–50% by vol-
ume alcohol. At least a tenth of the alcohol in ar-
rack blends must be from genuine arrack. Arrack
is used for hot drink preparations, for Swedish
punch, as an admixture for liqueurs, and in bak-
ing and as a flavoring ingredient in candy manu-
facture. Batavia brand arrack, with an alcohol
content of about 57% by volume, contains on the
average 92 mg acids, 189 mg esters, 21 mg alde-
hydes and 174 mg higher alcohols per 100 ml of
ethanol.

20.3.2.3.7 Liquors from Cereals

Typical products are grain alcohol and whiskey

(American and Irish brands are usually spelled

with an “e”, while Scottish and Canadian brands

tend to use “whisky”). Different cereals (rye,

wheat, buckwheat, oats, barley, corn, millet) are

used. The cereals are first ground, mixed with

acidified water, and made into an uniform mash

by starch gelatinization. Saccharification is then

accomplished by incorporating 15% kiln-dried

malt in a premashing vat and stirring constantly

at 56◦C. Saccharification proceeds rapidly

through the action of malt diastase enzymes.

The enzymes are inactivated by heating the

mash to 62◦C. This step is followed by rapid

cooling of the mash to 19–23◦C. The sweet

mash is fermented by a special yeast and is then

distilled. Grain liquors are obtained by distilling

the mash, while malt liquors commonly are

produced by distillation of the wort. Simple stills

are used for distillation in small plants, while

both distillation and rectification are achieved on

highly efficient, continuously run column stills

in industrial-scale production. According to the

process used, the yield is 30–35 l of alcohol per

100 kg of cereal (e. g., rye), while the quality and

character of the spirits vary greatly. Simple stills,

with an unsophisticated separation of head and

tail fractions, provide characteristic products rich

in grain fusel oils. A modern distillery is able to

remove the fusel oils to a great extent, yielding

a high percentage grain alcohol, from which it is

then possible to make a mellow, tasty, pure grain

brandy with a subtle aroma. The final flavor of all

these products is dependent on well-conducted

aging in wooden casks.

Whiskey, depending on the kind, is made by dif-

ferent processes. The raw material for Scotch sin-

gle malt whiskey is barley malt which has been

exposed to peat moss or coal smoke during kiln

drying. Such smoked malt is mashed at 60◦C

and filtered. The resulting wort is then fermented

at 20–32◦C after the addition of yeast (Saccha-

romyces cerevisiae). Irish whiskey is never made

from smoked malt. The distillation is conducted

in two steps, sometimes in simple pot stills. The

harsh, raw liquor is collected in the first distilla-

tion step. The undesirable harsh components are

removed in the head and tail fractions in the sec-

ond distillation.