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.

BREWING SUGARS

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.

231--Cane Sugar

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."]