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heat of the whole, after the mashing, 150°; so that the water has lost 32° of heat, while thev malt (its . temperature before mixture was 48°) gained 102°. The weight of the water, reckoning it

This would make the specific heat of the malt 0'6[>, which is probably considerably above the truth; for, according to the experiments of Dr Crawford, the specific heat of barley is only 0*421; so that our supposition, that the mean temperature after mashing was only 150°, is not quite accurate. Were we to suppose the specific heat of malt to be 0*42, which cannot be very far from the truth, in that: case the mean temperature, after mashing, would be 169°, if the water was 192° and the malt 48°, and the weight of each as above stated.

In another experiment, in which sixty bushels of malt were mashed, the heat of the water was 180°, that of the malt 56°, the temperature, on adding the malt to the water and mixing it well, was at the surface 141°. Four hours after, when the wort began to be drawn off, its temperature was 150°, and that of the surface of the mixture of malt and water in the mash-tun was 138°.

The bulk of water was 66£ bushels, its weight...5157* lbs. The weight of the malt was 2283*6 lbs.

Any person may easily, from these data, calculate what the heat of the mixture after mashing ought to be, supposing the specific heat of the malt to be at 51 bushels, was That of the malt was

3965*25 lbs. 1788-80 lbs.

0*42. The common formula for the calculation is

S = ^ x w—?? jn which S denotes the specific heat H x m — o of the malt, W the weight of water used, w iter temperature, B the weight of malt used, and b its temperature, and m (which in the present case is the quantity sought) thfe temperature after mixture. We do not think it worth while to give any more examples of these changes of temperature, though we are in possession of abundance of them ; because we do not conceive that they can lead to any useful results.

After the mash has continued for about three hours (or longer or shorter according to circumstances), a stop-cock, placed below the false bottom in the mash-tun, is opened, and the wort allowed to run out into a vessel prepared to receive it, and known by the name of underbade. At the same time the cover is taken off the mash-tun, and quantities of water of the temperature of 180° are occasionally sprinkled over it from the boiler, which had been again filled with water to be heated as soon as the water for mashing was drawn off. No specific directions can be given respecting the quantity of hot water added in this manner by sprinkling, because that must depend upon the views of the brewer. If he wishes to have ale of very great strength, he will, of course, add less water ; if the ale is to be weak, he will add more. The best way is to determine the strength of the liquor as it flows into the underback, by means of a saccharometer, or by taking its specific gravity. When the specific gravity (at 60°) sinfcs to 1*04 or 1-05, or when it contains only 36£ or 46£ lbs. per barrel of solid matter in solution, it would be useless or injurious to draw any more off for making strong ale. But an additional portion may still be drawn off and converted into small beer. We have seen the brewers in Edinburgh continue to draw off small beer from the mash-tun till the liquid indicated only 23£ lbs. per barrel, or even till it indicated 17£ lbs. per barrel; that is, till its specific gravity at 60° was reduced to 1027 or 1-020. Indeed the strength of small beer is often much weaker than this when it is obtained from malt without drawing off any strong ale wort; but when it is the residue of strong ale, it is necessary to make it stronger, otherwise its quality will be bad. About fifty years ago, it was customary with some of the small-beer brewers in Edinburgh to make the small beer of considerable strength; and after the exciseman had determined its quantity, and the duty to be paid on it, they diluted it largely with water, just when they were sending it out of the house. This fraud was easily put in practice, because the small beer is usually disposed of the moment it is mixed with the yeast, and before it has undergone any fermentation whatever. It ferments sufficiently in the small casks in which it is sent to the consumers. In Edinburgh it is customary to bottle this small beer, which makes it clear and very brisk, and, consequently, very agreeable to the palate.

Neither can any general rule be laid down for the specific gravity or strength of the wort when it begins to flow from the mash. It will obviously depend upon the goodness of the malt, and upon the quantity of mashing-water employed, when compared with the quantity of malt. We have seen it begin to flow from the mash-tun of the specific gravity 1 084, 1-0805, 1-0815, 10835, 1-091, 1-094, or containing respectively 78J, 74j, 75£, 78, 85, and 87f lbs. per barrel.

The wort, as it first flows from the mash-tun, is a transparent liquid of a fine amber colour, a peculiar smell, and a rich, luscious, sweet taste. If it is cloudy, as sometimes happens, it is a proof that the water used for mashing was of too high a temperature. We have seen the wort run cloudy from the mash-tun when the temperature of the water had been as high as 200° or 191°, but never when it was no higher than 180°. This affords an additional reason with the brewers for keeping the temperature of the mashing-water low. But we have some doubts about the accuracy of the reason. For, when the wort is afterwards boiled, it always deposits a copious flocky sediment. The boiling would render even turbid wort transparent, and would not probably increase the sediment much. At the same time it must be acknowledged that some obscurity hangs upon this part of the process of brewing. For we have seen wort continue opaque during the whole process of boiling, cooling, and fermenting, and requiring ultimately to be clarified, or fined, as the brewers termed it, by means of isinglass. The substance which rendered the ale in this case turbid seemed to be a variety of starch, or some particular form of that substance, for it was completely precipitated by infusion of, nutgalls, and the precipitate was redissolved by the application of a moderate heat.

The flowing of the wort from the mash-tun takes up six or eight hours. As it advances the colour diminishes, the smell becomes less agreeable, and the taste less sweet. At last the colour becomes nearly opal, and ¿he smell becomes sour, and somewhat similar to the odour emitted by an infusion of meal and water left till it has become sour. Yet it produces no change on vegetable blue colours.

If the wort which first comes over be evaporated to dryness, it leaves behind it a yellow-coloured residuum, which has a sweet taste, dissolves readily in water, absorbs water from the atmosphere, and becomes clammy, and similar in appearance to treacle. Its specific gravity is 1*552. This does not differ much from the specific gravity of common refined sugar, if we take a mean of the experiments of Fahrenheit and Hassenfratz. Fahrenheit found the specific gravity of sugar 1*6065, while Hassenfratz found it T4045, the mean of which is 1*5055. There can be no doubt that this residue contains a good deal of sugar, precisely the same in it& properties with the sugar into which starch is converted by boiling it in a very dilute acid, called by chemists glucosin. But it is mixed likewise with a considerable portion of starch, which has become soluble in water, without being converted into sugar. For wort gives a copious precipitate with the infusion of nutgalls, and this precipitate is redissolved by a moderate increase of temperature,—properties which characterise starch.

From the experiments of Saussure, it would appear that starch-sugar is nothing else than a combi-, nation of starch and water. Hence it is probable that, during the mashing, a combination takes place between the starch of the malt and the water, the result of which is the formation of starch-sugar. This sugar agrees in its properties with the sugar of grapes. It crystallizes in needles grouped together in the form of small sphericles like granulated honey. It does not go so far in sweetening as common sugar, and, like sugar of grapes, it ferments without the addition of yeast. We' have attempted in vain to separate the saccharine part of the residue of wort from the starch. When alcohol is poured over it, no solution takes place ; but such is the affinity of the residue of wort for water, that it deprives the alcohol of a portion of its water, just as carbonate of potash or muriate of lime does, and a very viscid liquid, consisting of the residue of malt dissolved in a very small quantity of water, is formed at the bottom of the vessel.

It is exceedingly difficult to evaporate wort without partly decomposing the extractive residue. The best way is to put it upon a very flat dish, and to apply a heat not greater than 120°. We have charred it completely in a glass vessel, filled with alcohol, without applying heat sufficient to make the alcohol boil. Indeed we never succeeded in obtaining the residue of wort without its colour being a good deal darker than that of the wort from which it was obtained. "

The wort which runs off last contains very little saccharine matter; but some starch and mucilaginous matter may still be detected in it. The flavour and beauty of the ale is increased if we take only the wort that runs first off, and throw away the last drawn worts, or employ them only in the manufacture of small beer.*

* Brewers differ in practice when drawing off the wort. When the whole is intended for ale the first mash is laid on at a greater length, to obtain the greatest possible quantity of wort of a required strength. The mash holds wort of the same weight as that drawn off. The second mash not only takes up the wort which saturates the goods, but the formation of saccharum still proceeds, and when this mash is run, supposing its weight 40 to 45 lbs. per barrel, the saccharum that remains in the mash is only that contained in the wort which is taken up by the malt left in the mash-tun. The water run into the mash, say ten barrels added to that which saturates the malt, will make fifteen barrels, of the weight of 13 lbs. of saccharum per barrel, allowing wort of the weight of 40 lbs. to have been left in the second mash. Most brewers, therefore, use the third mash for small beer, as, were they to mix this weak third mash with the two first, they would lose more by boiling down to strength than its worth, besides damaging their ale.

The weight of the saccharine extract of the first and second mash of a brewing of ale will be in proportion to the required price of the production.

The price of ale in Edinburgh increases from £3 upwards to £8 per hogshead, and the strength or weight of sacGharum is in proportion. The weight of a barrel of wort, boiled and cooled down

2. The next process in brewing is the boiling of the wort. The wort is pumped up from the under-bach into the copper boiler, where it is boiled till it has acquired the degree of strength which is wanted by the brewer.

It may be proper to give some examples of quantities, to enable the reader to form a better idea of the effect of the boiling.

From sixty bushels of malt there were obtained 23-465 barrels of wort, of the strength of 64*37 lbs. per barrel, or q{ the specific gravity 1*0683. It was boiled down to 17*736 barrels of the strength of 82-7 lbs. per barrel, or of the specific gravity 1*089.

From sixty bushels of big-malt there were obtained 23*8193 barrels of the specific gravity 1*0648, or of 58*75 lbs. per barrel of saccharine matter. It was boiled down to 17*736 barrels of the specific gravity 1*078, or of 72J lbs. per barrel of saccharine matter.

to the fermentation point, will be from 50 lbs. to 140 lbs. of saccharine extract, according to the above prices.

The destruction of the wort by evaporation on the coolers is so great as to make it an object of vfest importance to devise a method of cooling without so much loss. Distillers who run their wort into the coolers from the mash have accomplished their object by running the wort through pipes of great length immersed in water. But this method of cooling does not answer the brewer of ales, owing to the fecula remaining in solution^ and damaging the quality of the production, when such a plan is adopted.

Coolers formed of iron plate answer the purpose better than the wooden coolers now in general use. On the iron cooler, by lowering its temperature by running cold water over it, and mopping it clean and dry, wort, by being then spread to the depth of 1£ or 2 inches successively, may be cooled down, even in summer heats, to as low a degree as brewers require.—W. S.

From seventy-two bushels of malt 24*1388 barrels, of 78-6 lbs. per barrel were obtained. It was boiled down to 17 barrels of the specific gravity 1*1055, or of 98§ lbs. per barrel of saccharine matter.

From fifty bushels of malt 17*444 barrels of wort were obtained, of 74-125 lbs. of saccharine matter per barrel. It was boiled down to 12*083 barrels of the specific gravity 1*1015, or of 94J lbs. per barrel.*

Various contrivances have been fallen upon to economise the boiling process; but these will come under our consideration with more propriety when we proceed to give an account of the utensils in a London brewery.

The flocky precipitate which forms during the boiling of the wort, as far as we have been able to determine its properties, approaches nearly to the nature of gluten or vegetable albumen, for these two substances differ very little from each other. ;

While the wort is in the boiler, the requisite quantity of hops is added to flavour the ale, and render it capable of being kept for a considerable length of time without souring. Hops, as is well known, are the seed-pots of the Humulus lupulus or hop-plant, which is cultivated in considerable quantities in the south of England, especially in Kent and Hampshire. The seed-pots of this creeping plant are collected when ripe, and dried upon a kiln. They are then packed up in bags, and sold to the brewers. Hops

* In these examples, the worts are given as boiled and cooled down to the point of fermentation.

are well known to have a peculiar bitter taste, and a weak aromatic odour, and to possess sedative qualities to a considerable extent. A pillow filled with hops has often been found to induce sleep when every thing else has failed. If they be digested for some days in alcohol, that liquid acquires a slight greenish colour, a peculiar taste, and an odour in which that of the hop can be distinctly perceived. If the alcohol, previously freed from the undissolved matter, be distilled in a retort, there remains behind a solid green-coloured oil. It is to this oil that hops owe their peculiar smell. Its taste is peculiar, sharp, and scarcely bitter, but putting one in mind of the pecu-" liar flavour of good ale. This oil is the part of the hops which gives ale its distinguishing flavour. It is- apt to be dissipated by long boiling. Hence, when hops are too long boiled in wort, the aromatic odour and peculiar flavour are nearly dissipated, and a bitter taste substituted. It is the opinion of brewers, that the intoxicating qualities of ale are to be partly ascribed to the oil of the hop. Indeed it has been pretty common to ascribe intoxicating qualities to bitter-tasted substances in general. Thus, a woman of the name of Johnston, who kept a public-house a little to the south side of the Meadows, near Edinburgh, about the beginning of the last century, was famous for brewing a pleasant and very intoxicating ale; and the last quality was universally ascribed to the broom tops which she employed as a bitter instead of hops. This woman's name is re membered, because her ale and her house are celebrated in the poems of Allan Ramsay. But the opinion above stated, though very general, does not appear to be founded upon any precise experiments or observations. We are not acquainted with any volatile oil which produces intoxication ; though some of them, as oil of turpentine, act with great energy upon the stomach. No infusion of any bitter whatever, not even of hops, is known to produce intoxication ; nor is any effect in the least similar to intoxication produced when considerable quantities (2 oz. per day for example) of Peruvian bark are swallowed in substance.

Besides the volatile oil, hops contain likewise a quantity of bitter principle, which may be easily extracted from them by water. As far as we are able to determine the point, this bitter matter possesses the characters of the bitter principle in perfection. No re-agent that we tried is capable of throwing it down except acetate of lead, a somewhat ambiguous precipitant, because it throws down the greater number of vegetable substances, and because the lead in this salt is partially thrown down by carbonic acid, if it happens to be present in the solution. -Nitrate of silver is likewise a precipitant, throwing down the bitter principle of hops in light yellow flocks. But this precipitant is also somewhat ambiguous, for the same reason that renders acetate of lead so. The bitter principle of hops is likewise very soluble, both in water and in alcohol.

Hops communicate both their flavour and their bitter taste to wort. The quantity employed varies very much, according to the taste of the persons who are to drink the ale. The stronger the ale, the greater is the quantity of hops which it can bear without injury. In general, English brewers employ a much greater quantity of hops than the Scotch brewers. To elucidate the subject, we shall give a few examples of the quantity of hops used in making Edinburgh ale ; which is known to be mild, and, in general, is much relished by most of those who are in the habit of drinking ale.

Sixty bushels of malt yielded 11-75 barrels of strong ale wort, measured at the end of the boiling, and 40 lbs. of hops had been mixed with it in the boiler.

Forty-seven and a quarter bushels of malt furnished 10*83 barrels of wort, measured after being boiled and cooled, and 36 lbs. of hops had been mixed with it in the boiler.

Sixty bushels of malt furnished fifteen barrels of wort, measured after boiling and cooling, and 45 lbs. of hops had been mixed with it in the boiler.

Sixty bushels of malt from big furnished 14*7 barrels of wort, after being boiled and cooled. It was mixed with 40 lbs. of hops in the boiler.

In another brewing in which 72 bushels of malt from big, furnished 10i barrels of wort, 66 lbs. of hops had been added in the boiler.

In general, when the ale has considerable strength, the Edinburgh brewers are in the habit of adding one pound of hops for every bushel of malt employed. Sometimes, indeed, when they wish their ale to be very superior in flavour and quality, they employ a greater quantity of hops than even this. Thus we have seen 100 lbs. of hops boiled in the strong ale wort extracted from 72 bushels of malt/ When the ale is but weak, and consequently cheap, the usual allowance is one pound of hops to a bushel and a half of the malt.

The peculiar flavour of the best ales is communicated by the skilful use of the hops; and both the quantity employed and the time of the boiling, require the best consideration of the brewer. The best hops for ale are the Kent growth, of a pale-green colour, glossy, and having an aromatic flavour. No arbitrary rule can be given for the quantity to be used in brewing ales of different strengths, and much depends on the views of the brewer, with regard to the future disposal of the ale.

In Edinburgh they use from 1 lb. to lbs. per bushel for the best strong ales, using a third more for the summer keeping ale than for winter ale, or ale brewed for immediate use. The peculiar substances in hops connected with brewing have been already noticed. The bitter ingredient if too much is used, renders the ale very unpalatable. The Nottingham brewers, who are the best in England, sometimes use as much as 15 lbs. of hops to nine bushels of malt. The porter brewers of London use very little Kent hops of fine quality ; but prefer the cheaper red hops of Sussex and other districts. The quantity of hops, as used by-the English provincial brewers, is 2£ lbs. per barrel of 36 gallons made from 3 bushels of malt.

3. After the wort has been boiled down to the requisite strength, which, in Edinburgh, is commonly between the specific gravities 109 and 1*10, it is let out into the coolers. The coolers are floors of wood, surro mded with a wooden ledge, and water-tight, placed in the most airy and exposed situation in the brewery. They are of such a size as to hold the whole of the wort at a depth not exceeding three or four inches; so that, in large breweries, they are of an enormous extent. The object is to cool down the wort as rapidly as possible to the temperature of the atmosphere ; because, if it were allowed to remain long hot it would run the risk of becoming sour, which would spoil the whole process. A great deal of the superiority of some breweries over others depends upon the construction of the coolers, or rather, upon their being as well adapted as possible for reducing the temperature of the wort speedily to that of the atmosphere. A free current of air ought to pass over them, and great care should be taken to keep them perfectly clean.

The wort is either pumped out of the boiler into the coolers, or let into them by simply opening a stop-cock, according to the construction of the brewhouse. It soon spreads itself over all the surface of the coolers, and a very great evaporation is the consequence.

This evaporation ought always to be taken into consideration by the brewer; because it both materially adds to the strength of the ale and diminishes its quantity. The amount of it depends upon the temperature of the air compared with that of the atmosphere, and upon the skill with which the coolers have been constructed. We shall give a few examples of the quantity of evaporation which took place during the cooling of worts in coolers by no means remarkable for the goodness of their construction.

Temperature of the Wort when let into the Coolers.

Temperature «f ditto when Cold.

Quantity of Wort when let into the Coolers in Ale Barrels.

Ditto when Cooled.

Quantity ' evaporated in Ale Barrels.

Time of Cooling in Hours.

160°

56°

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