Sugars in Brewing
This material is from H. Lloyd Hind's Brewing Science
and Practice, which was written
in the 1930s and stands as the best source of information on
traditional British brewing practice. There is a great deal of
very technical information about the production of various sugars
and their chemical/physical structure, some of which may not
even be accurate given advances in the physical sciences, and in
any case is well beyond our needs. There is also information about
specific sugar blends produced for the British brewing trade, but
without brand names; in any case, the information is more than
50 years old so I left it out.
230--Sugars as Malt Adjuncts
Various sugars and starch conversion products can be added in the
copper to supplement the fermentable extract formed in the mash tun
by conversion of the starch of malt, but similar restrictions in
respect of the quantity used apply as with cereal adjuncts, on
account of the lack of nitrogenous yeast nutrients. They provide a
means for varying the composition of worth, within limits set by
the requisite balance between sugars and non-sugars, supply
extract which may be either entirely or only partly fermentable,
give characteristics of fulness and flavour that are appreciated
in some cases, increase the stability of beer by replacement of
nitrogenous extract and yield beer that will become more readily and
rapidly brilliant than when brewed with malt alone. Primings are
strong solutions which must not, in this country, exceed 1150
specific gravity but should not be much less. They are sometimes
added in the fermenting vessel at the close of primary fermentation
but, more frequently, in storage tank or cask to promote rapid
condition and, in some cases, on account of their flavour. The
sweet and luscious flavour of some sugars does not entirely
disappear when the sugar has been fermented but gives additional
fulness to the beer. In some cases, sugars which are not entirely
fermentable are selected.
The sugars used in brewing comprise:
Maltose, which might appear to be the most suitable sugar to replace
that formed from malt in the mash tun, is not used in the pure state,
but exists as a constituent of corn syrups with dextrin and glucose.
Lactose differs from cane sugar, invert sugar, maltose and glucose
in that is is unfermentable by ordinary brewery yeasts, while certain
of the higher starch conversion products are appreciated because
they are only partly or slowly fermentable.
- (1) Cane sugar, derived from the sugar cane and, much less frequently,
from sugar beet.
- (2) Invert sugar, made by inversion of cane sugar.
- (3) Starch sugars, including corn syrups and glucose, manufactured
by the conversion of the starch of cereals, usually maize [that's
_corn_, Norte Americanos].
- (4) Mixtures of these, their utility in copper or cask depending on
their flavour and fermentability.
- (5) Caramels, made from cane sugar or glucose.
- (6) Lactose or milk sugar, which is only used in very small quantity
in some milk stouts.
- (7) Honey, even less used.
The sugars obtained from the sugar cane, sugar beet, sugar maple,
certain palsm or the stem of sorghum are, when purified, of identical
chemical composition. All of them are sucrose. The natural juices
from which they are derived, however, differ very considerably in
flavour owing to the many other substances which they contain. For
example, the root of the beet contains a larger proportion of mineral
salts than the sugar cane and decomposition products are formed with
the larger quantities of lime necessarily used in the course of
clarification, which give an objectionable flavour to the juices and
raw sugar. These render the latter unfit for consumption until
refined. The raw sugars from the cane are, on the other hand, very
luscious but they do not all taste the same, varying considerably
according to the place in which the cane was grown or the treatment
they received during extraction and preparation, characteristic
differences being found in sugars from Cuba, Java, Barbadoes, Trinidad,
St. Domingo, Mauritius, etc. Since the value of cane sugars in
brewing depends so largely on the flavours they communicate, even
after all the sugar itself has been fermented, the principal source
must be the sugar cane, which yields juices possessing these
properties in their most attractive form. The final product of the
refineries, from whatever source it originally came, is among the
purest substances commercially obtainable, but it lacks the
distinctive characteristics of flavour demanded in brewing. As a
source of carbohydrate extract it is unexcelled and can be used
without hesitation under circumstances in which those flavours are not
required, but the raw or partially refined sugars from the cane are
more attractive in most cases.
[... some technical information on the refining process deleted ...]
Usually the lusciousness of the sugars increases with greater
proportions of other substances derived from the cane, some of which
are in a colloidal state, and many such sugars, among them West
Indian and Brazil sugars of comparatively low polarisation, are used
in brewing on account of the fulness and sweetness they give. Other
low polarising sugars, such as that from Mauritius, have a somewhat
acrid after-flavour. On account of these different flavours, great
care must be exercised in selecting brewing sugars, fermentation
tests being desirable as the original flavour is not always a good
guide to that left after the sugar is removed.
Cane sugar is used both in the copper and as a priming. Raw sugars
of good class are generally employed for the former purpose and
when of good class are generally employed for the former purpose
and when of suitable purity should not contain excess of undesira-
ble substances or micro-organisms. Sugars of this type and pure
crystals can also be used for priming but candy sugar is preferred
by many. Cane sugar is rapidly inverted when added to cask, the
change being generally complete in about 24 hours. This process is
believed to be an essential preliminary to fermentation. It is
carried out by the enzyme inertiase or sucrase secreted by the yeast
and does not appear to affect the fermentative activity of the
yeast or influence the rate of fermentation. Baker and Hulton
found that cane sugar and invert primings were fermented at sub-
stantially the same rate in beer under ordinary cellar conditions
and that about one-third of either sugar still remained
unfermented after 7 days in cask when added at normal priming rates.
[Hind goes on to offer technical information about the cane sugars
used in brewing: refined crystals, candy sugar, brown sugar and
yellow crystals. "The yellow crystals represent the high grade
products turned out at many cane factories, and of which Demerara
sugar is well known."]