BREWING is the art of making malt liquors, such as porter, ale, and beer, which have a vast number of local appellations, depending upon their taste, colour, &c.
The art of brewing is of great importance in this country, where the principal beverage of the inhabitants consists of fermented malt liquors, which are generally considered as the least prejudicial to the constitution, of any of those inebriating liquors, which, in the present state of society, are looked upon as essential to the sup port of the human frame. The practice of brewing porter is brought to great perfection in London, and many other towns are celebrated for their ales, &c.; but the principles upon which these advantages depend, are not perfectly understood. The superiority of par• ticular ales, is generally attributed to local conveniences of water, climate, malt, &c. which might, in a great degree, he attained, from a particular management of the processes upon which the art of brewing depends. It would be presumptuous to attempt to settle the prin ciples of an art so complicated ; but we shall endeavour to describe faithfully the different processes of brewing, from the extraction of the virtue of the malt, to the fin ing of the beer. This is all that our limits will per mit us to accomplish ; and we hope it may be found of utility to the practical brewer, in giving him the detail of the art as practised in London, where por ter is brewed on such a large scale, and where the most scrupulous attention is paid to the economy of materials. and the perfection of the process. In doing this, we shall first give a full description of a London brewery, and of the various utensils employed in it ; and then a detailed account of the different processes which are employed in this useful art. But before we proceed to any of these heads, we shall first give a general outline of the different operations in brewing.
The Principal ingredients employed in brewing beer, are malt and hops, from which the virtues are extracted by solution in hot water, and this extract is fermented with yeast. Malt is made from barley, which being steeped in water, and then spread out in thin layers, vegetates, and produces a sweet substance termed sac charum, which did not previously exist (at least in the same form) in the dry corn, and which disappears if the process of vegetation (or germination as it is called,) is carried too far. In order to prevent this, when the corn is judged, by known signs, to be in that stage which pro duces the greatest quantity of saccharine mutter, the germination is stopped by drying the corn upon a kiln. This evaporates the moisture, and prevents the farther growth of the corn, now converted into malt, which will keep till it is wanted by the brewer. The malt in the _ _ _ brewer's hands is first ground coarsely, so as to break every grain into 3 or 4 pieces. The malt, or, as it is now called, the grist, is put into a large vessel, termed the mash tun, and hot water admitted into it from the copper, where it remains till the water is supposed to have extracted sufficient sweetness from the goods, as the malt is called in this stage of the process. The goods arc stirred up at intervals, to expose every part of the mass to the action of the liquor ; and for a cer tain time, at the conclusion of the mashing, it is not disturbed, that the extract (which is called wort,) may not be thick, from holding the gross parts of the flour and mucilage of the malt in mechanical mixture. After being left at rest a short time, these gross parts subside upon the goods ; and the wort running through them, when let off, is, in some degree, filtered, and flows clear into a vessel beneath the mash tun, called the under back. From this vessel it is again pumped up into the
copper ; and when the hops arc put in, it is boiled for some time, in order to extract the bitter of the hops, to coagulate the mucilage extracted from the malt, and evaporate a portion of the water used in mashing. When sufficiently boiled, the wort is run off into a vLs sel called the hopback, which detains the hops, but per mits the liquor to flow into the coolers. These are large vats, not more than 5 inches deep, in which the liquor remains till it is cooled to a proper temperature for the process of fermentation ; which gives the strength or spirituous quality to the beer. This is effected in vessels, called squares or gyle tuns, in which a sufficient quantity of yeast is added, to put the liquor in fermen tation ; the symptoms of which arc an internal commo tion of every part of the liquor, caused by the extrication of gas, which rises through the fluid in innumerable bubbles, producing an universal motion, and a continual singing, and raising to the surface a constant stream of yeast, in which the bubbles of gas are enveloped. This yeast floats upon the beer, and is called the head. After this fermentation has continued some time, and the head does not seem likely to rise any higher, it is neces sary to put a stop to it, as it would be quickly succeeded by another fermentation, called the acetous fermenta tion : the first being called vinous, producing alcohol or spirit ; while the second generates acetic acid, or vinegar. This operation of checking the fermentation is called cleansing. It is performed by drawing off the beer, and putting it into small casks called rounds, where it still continues to ferment and disharge yeast for some time, the casks being filled up as they diminish in their When the working ceases, the casks are .lunged up to prevent it from growing flat ; and if every thing has been successful, the beer requires nothing but age to fine itself, and be fit for the table. In large breweries, the store of beer is not kept in the small casks, but in immense casks called the store vats, into which it is put from the rounds, as soon as the working ceases. When sufficient time cannot be allowed for the beer to fine itself, (that is, to deposit the mucilage which is suspended in it, and which gives it the ap pearance of clouds of lighter and darker colours,) preparation of isinglass and sour beer, called finings, is employed to precipitate the clouds, and render it trans parent ; a quality which is deemed a great recommen dation, as is also a fine colour, which, in some liquors, is produced by colouring. It frequently happens, that the beer does not turn out good, from acidity, flatness, &c.; and many methods are employed for improving it by adding various chemical preparations. This was formerly reckoned the most valuable branch of the art, and innumerable nostrums were considered by their possessors as invaluable secrets ; but of late the intro duction of the thermometer, in the operations of the brewery, has shewn, that more is to be obtained by con ducting the previous processes in a proper manner, than by trusting to remedies, for the errors arising from inaccuracy in the heats of the different liquors, or from inattention to the circumstances of the weather. &c.