A Treatise on the Art of Brewing
A Treatise on the Art of Brewing, Exhibiting the London Practice of Brewing, Porter, Brown Stout, Ale, Table Beer, and Various other Kinds of Malt Liquors by Friedrich Accum, Operative chemist, Lecturer on Practical Chemistry and Mineralogy, & on Chemistry applied to the Arts & Manufacturers; Member of the Royal Irish Academy; Fellow of the Linnean Society; Member of the Royal Academy of Sciences, & of the Royal Society of Arts of Berlin, &c, &c, was published in 1820. 1,500 copies of the first edition were sold within four months. The second edition was published the following year. Quotes in this article are taken from second edition (1821) unless otherwise indicated.
- My main object has been to divest the art of Brewing of the mystery in which it has been involved by interested persons; to enable the reader to avoid the mistakes frequently committed in following the empirical directions given in Treatises... and to lay before those who are interested in it that scientific mode of operating, which alone can lead to exact and successful results.
- Preface to the 1st edition
Historical Sketch of the Art of Brewing Beer
- The art of preparing vinous liquors from nutritive farinaceous seeds, previously subjected to the process of germination, or malting, appears to have been known and practised in very remote ages, among those people who lived in countries that are not adapted for the culture of the grapes.
- The invention of brewing is ascribed to the Egyptians... from whence it seems to have passed to... western nations... The town of Pelusium... was particularly celebrated for its manufacture of malt liquors. Herodotus attributes the discovery of the art of brewing to Isis the wife of Osiris.
- Tacitus informs us, that beer was known in very remote ages among the northern nations, and that this liquor was the favourite drink of the Anglo-Saxons, and Danes, as it had been of their ancestors, the Germans. Before their conversion to Christianity, they believed that drinking large and frequent draughts of fermented malt liquors was one of the chief felicities which those heroes enjoyed, which were admitted into the hall of Odin.
- After the introduction of agriculture into this country, malt liquors were substituted for mead, and became the most general drink of all the ancient Britons; both ale and beer is mentioned in the laws of Ina king of Wessex.
- Among the different kinds of drinks provided for a royal banquet in the reign of Edward the Confessor, ale is particularly specified. In Scotland and Wales they had at that time two kinds of ale, called common ale, and aromatie ale, both of which were considered... articles of great luxury among the Welsh. Wine, it appears, was then unknown even to the king of Wales.
- Mungo Park found the art of brewing beer... in the interior parts of Africa. They prepare the seed of the Holcus Spicatus nearly in the same manner as we do barley and he says that their beer was, to his taste, equal to the best strong malt liquor he had ever tasted...
- All the ancient malt liquors... seem to have been made entirely of barley, or some other farinaceous grain, and therefore were not generally calculated for long keeping, as this quality depends considerably, though not entirely, on the bitter principle of the hops... The use of [which] is of modern date.
Chemical Constitution of Malt Liquors
- Beer may be considered as the wine of grain, for it is the product of the fermentation of malt, just as wine is that of the fermentation of the grape, or other subacid fruits. Malt liquors, however, are distinguished from wine, chiefly by the larger quantity of mucilage and saccharine matter which they contain, and by the absence of super-tartrate of potash, a salt which exists in all wines made of the juice of the grape.
- The principal distinction of malt liquors is into Beer, properly so called, Ale and Table Beer, or Small Beer.
- Porter, [w]hich is commonly called Beer in London, must be pronounced the most perfect of all kinds of malt liquors.
- The processes employed for brewing this species of malt liquor, all unite to convert the substance from which it is produced into the most perfect vinous fluid that can be obtained from grain.
- The origin of porter is thus related by the Editor of the Picture of London:—"...[I]t ...became the practice to call for a pint or tankard of three threads, meaning a third of ale, beer, and twopenny, and thus the publican had the trouble to go to three casks, and turn three cocks for a pint of liquor. To avoid this trouble and waste, a brewer of the name of Harwood, conceived the idea of making a liquor which should partake of the united flavours of ale, beer, and twopenny. He did so... calling it entire, or entire butt beer, meaning that it was drawn entirely from one cask or butt, and, being a hearty nourishing liquor, it was very suitable for porters and other working people. Hence it obtained its name of porter."
- The name of Stout, or Brown Stout, is given to porter of more than ordinary strength.
- Ale is beer of a more syrupy consistence than porter; it contains a considerable quantity of undecomposed farinaceous matter; and saccharine mucilage, which impart... a clammy consistence and sweetish taste. Hence strong new brewed ale becomes muddy by a copious admixture of alcohol, whereas porter suffers no perceptible change...
- Small, or Table Beer... is a weaker liquor than ale, containing a larger quantity of water.
- Two parts of London table beer may be considered equivalent in strength to one of ale.
Quantity of Spirit
- Contained in Porter, Ale, and Other Kinds of Malt Liquors
- All kinds of malt liquor contain a common identical principle... namely alcohol or spirit. They are of course weaker than wines, and in general more liable to become flat and acescent from this circumstance...
Substances Employed for Brewing Beer
- Different kinds of corn are employed... In Britain barley is the most common grain... In America it is not uncommon to make beer of Indian corn and sometimes of rice. In the interior of Africa... the holcus spicatus.
- In some northern countries of Europe a mixture of rye and barley is used. In the East Indies beer is frequently made of wheat; but the grain which answers best is common barley, because its germination is most easily conducted, and its farinaceous matter is more readily converted into saccharine matter than any other seed, and affords it in greater quantity.
- In Scotland the species of barley called beer, or big, (hordeum hexastichon) is employed, which is a much more hardy... and ripens better in northern latitudes.
- The... only essentially necessary substances employed in brewing beer are water, malted corn, and hops.
- In domestic brewing, the addition of molasses, or coarse brown sugar, to the malt employed, greatly economises the fabrication of the beer.
Malt, and Process of Malting
- [B]arley, and other cereal and leguminous seeds, when penetrated first with a portion of water, and afterwards exposed to a moderate temperature, swell, and announce the intestine movement that is excited in them by the development of the germ which sprouts out of these seeds. ...it has acquired a saccharine taste and the water in which it is boiled extracts from it a real saccharine substance...
- When the grain has been thus changed the brewer... heats and dries the germinated seed by the action of fire and when... well dried he grinds the seed in order afterwards to prepare an infusion of it which when boiled with hops and suffered to ferment affords beer.
- The term malt is... applied to grain which has been made to germinate...
- The process of preparing malt is as follows:
The barley is steeped in water for... not less than forty hours, beyond that time the steeping may be continued as long as the maltman chooses. The barley increases in weight... and... in bulk..; during this change much carbonic acid is disengaged; the grains become somewhat tender, and tinges the water of a bright reddish brown colour. The water being drained away, the barley is spread about two feet thick upon a floor, where it is formed into a rectangular heap, called the couch, about sixteen inches deep. ...[I]t is allowed to remain about twenty-six hours. It is then turned by... wooden shovels and diminished a little in depth. This... is repeated twice a day or oftener and the grain is spread thinner... till at last its depth [is less than] a few inches. ...[I]t ...gradually ...absorb[s] oxygen from the air ...to convert it into carbonic acid. In consequence ...temperature slowly increases and in about ninety-six hours the grain ...average[s] about 10° hotter than the surrounding air.
- At this time the barley... becomes again so damp that it wets the hand; this is called sweating.
- The great object of the maltman is to keep the temperature from becoming excessive [within 55° to 62° F].... by frequently turning the grain.
- During the sweating, the roots... begin to appear, and rapidly increase in length till checked by frequently turning the malt. About a day after the sprouting... rudiments of the future stem called acrospire... rises from the same extremity... and advancing within the husk, at last issues from the opposite end; but the process of germination is stopped before... such progress.
- As the acrospire shoots along the grain, the mealy part of the corn undergoes a chemical change. The glutinous and mucilaginous matter is taken up and removed by the embryo plant; the texture... becomes so loose that it crumbles between the fingers. When the acrospire has come nearly to the end of the seed the process is stopped by drying the malt upon the kiln.
- The degree of heat at first does not exceed 90° but it is raised very slowly up to 150° or higher... It is then cleaned, to separate the rootlets, which are considered as injurious... formed chiefly from the mucilaginous and glutinous part...
- The starch is not employed in their formation; but undergoes a change... for the future nourishment of the plumula, or embryo plant. It acquires... the property of forming a transparent sweet solution with hot water, approaching to the nature of sugar.
- [M]alting... is... germination artificially excited, with the view of converting the fecula, or starch of the barley, into saccharine matter... by the abstraction of carbon... on the malt floor. ...[H]owever, ...the whole starch does not suffer this change; a portion... remains in the grain, which may even be extracted from it pure.
- The malt distillers add to the malted grain, which they ferment, a certain quantity of unmalted corn, nearly ground to powder, and the proportion of unmalted corn has... gradually... increased as to exceed considerably that of the malted grain.
- This mixture they grind to meal, infused with water, at a heat considerably lower than that... used by the brewers, and employ much more agitation to mix it... The wort is drawn off and cooled in the usual way, and fresh water poured on to exhaust the grain.
- The wort thus formed is not so transparent as that from malt, but its taste is nearly as sweet. It would appear... the starch in the raw grain undergoes a certain change during the mashing, and is brought towards the state of saccharine matter.
- The wort of raw and malted grain is, by the addition of yeast, made to ferment easily, and affords a strong vinous liquor.
- A Treatise on the Art of Brewing. Exhibiting the London practice of brewing, etc. (1820) @The British Library
- A Treatise on the Art of Brewing (1821) 2nd edition, @Google Books.