EXTRACTS

MEETING HELD FRIDAY, JANUARY 22^nd, 1897, AT THE QUEEN’S HOTEL, LEEDS.
Mr. Harold Trinder in the Chair.

The following paper was read and discussed :—

Extracts
By Arthur Rogers, F.C.S.

This paper is intended to be a practical one, dealing with the best method of obtaining the highest possible produce from the material employed in the brewery. I do not propose to touch on the scientific side of the question, but trill speak only of the extract that can be obtained on a practical scale in the mash-tun.

The question of produce is one of the highest importance in the brewery, and in these days of keen competition may become the question of the existence of the brewery itself. I cannot do better than quote to you what Mr. C. H. Tripp says on this matter, in his book on Brewery Management:—

“If a 500-quarter heap of malt that we know has been made from a very fair average run of barleys, possibly from the same lot, and we discover on running through the brewer’s book, that one day he obtained 87·5 extract; the next, 86·5; the following, 85·5; then 87; and perhaps one as low as 81, while the mash each time was the same, viz., a 20-quartcr one.

“If on careful examination of weight of malt, sacks used, and grinding, we find no variation in these, then the cause of such inequality of extract arises from careless brewing operations; just let us consider what we lose by the drop or loss of extract from 87·5 to 85, viz., 2½ lbs. We note we mashed 20 quarters, and hence 2½ lbs. X 20 = 50 lbs. represents the extract lost. Had we secured this in our rounds it would have meant 2½ barrels of 20-lb. beer extra, or, allowing 5 per cent, waste during fermentation, 2½ barrels for sale, which by only getting 85 extract, we have never seen. Now a 20-lb. beer will realise at least 40s. a barrel, and 2¼ barrels at 40s. = £4 10s., and taking 30 per cent, off for discount, and expenses, &c, viz., £1 7s., we have £3 3s. net absolutely lost on this single brewing of 20 quarters through the extract dropping from 87 to 85. Should this happen only 20 times in a year, it will be an absolute loss to the brewer of £63.”

The above may not be new to you, but it is a fact that the brewer should frequently have brought before him. I hope, however, that this paper will lend itself to interesting debate, and thus help us to learn from one another our mutual experience on the subject. I have, therefore, quoted from Mr. Tripp, as he puts the matter in a clear, practical way, easily understood.

Malt will yield an extract of 78 per cent, its weight, which is equivalent to an extract of 100 lbs. (brewers’ pounds) from 336 lbs., or a quarter of malt. Unfortunately the English brewer can only secure 70 per cent, extract from his malt, or an extract of 90 lbs. per quarter. This is owing to some 8 per cent, of the starch being vitrified or unmodified. It is, however, by no means easy to obtain even this 90 extract, and I venture to point out the following few hints, in order to render its attainment the easier. First, the malt. This should be well grown up, the acrospire all but protruding. The malt should not have excess of culms or excess of acrospire, as both of these tend to decreased extract. The grinding should be watched carefully, and the desired medium should be maintained continually. Fluted rollers are of great assistance in the mill, as they help to catch smaller corns that might otherwise escape un-ground.

Now to deal with the making of the extract in the mash-tun. We take it for granted that the mash-tun is provided with some exterior mashing-machine of the Steele pattern. Let the grist flow evenly from the case, which should be inclined at a steep angle, and let the grist and water mix thoroughly in the proportion of 1¾ barrels water to a quarter of malt, which is about the requisite proportion to yield a perfect extract.

As regards the striking heat of the water, the lower this can be arranged to suit the resulting beers, the higher will be the extract. Rakes should be employed in every tun. Rakes have fallen into much abuse, mainly on account of their misuse by many brewers. I know of cases where the brewer ran his rakes as fast he did his sparge, and, as a consequence, shot his mash over the floor, and pressed it through the slots of the plates, so that he stopped up his taps. The result was the rakes were removed us being a nuisance, and only an obstruction in the tun. His opinion of this was strongly confirmed by the local excise-man who was about to re-gauge the tun.

The rakes ought to be run slowly, even if they take 60 seconds in revolving in an average sized tun. Probably three revolutions at this speed will be all that is required.

Extracts are often diminished when the tun has to be filled to its utmost capacity to supply a strong gravity beer, which has to be boiled in one length in a limited copper.

Many brewers find that when they brew a strong beer the extract is very low, and that, consequently, as this beer pays high duty and costs much to produce, the loss thereby is heavy. In brewing a strong beer with a full tun I would suggest the following:—

Get the mash in with the minimum water, which must not be less than 1½  barrels to the quarter. Stand the usual time, and do not underlet unless you are obliged to raise your initial heat. Set taps and drain your tun dry before you touch the sparge. When the tun is dry, stop taps and sparge a quantity of water, and repeat the operation, not having the sparge running at the same time that the taps arc flowing. Take care that when you have got your length that no wort is left in the tun. Many brewers think that if the last runnings from the tun weigh only 1 lb., or thereabouts, they have got their full extract, but they do not think that there may be several barrels in the tun left behind which weigh 1 lb. each, and multiplied may make a serious loss in the bulk. There is nothing so slovenly and wasteful as to see the waste-pipe from a mash-tun running a lot of frothy wort, which the brewer says only weighs 1 lb., and is no good, as it has a lot of starchy matter in it. To secure a full extract the tun should run almost dry, leaving not more than a barrel of wort in it. Otherwise, if even all the extract is out, a useless waste of water ensues.

The wort circulator and the underlet may help to mix the worts, but they cannot improve the extract if the mash itself has been carelessly conducted. Defective sparging will lose much extract. Care must be taken that the sparge sprinkles every portion of the goods.

Sugar.—It is essential that sugar should be completely dissolved, and that every portion of the plant that the solution passes over should be well swilled. A loss of extract often ensues, from the fact that a strong solution of sugar has to pass over the whole of the plant before it can reach the collecting vessel. To avoid this, I recommend the erection of a special vessel which stands just above the collecting vessel, which latter contains a coil to cool the sugar before the charge is taken. Before erecting this, it is well to obtain permission from the Excise Supervisor.

In regard to raw grain, the main question as regards extract is the importance of its being intimately mixed with the malt in the tun, so that every portion of starch is at once in contact with diastase.

In conclusion, I think it is a fallacy to imagine that the brewer can get too much extract from his malt. He may get undesirable matter from very weak last runnings, but this is not real extract; it will weigh nothing, nor does it help him to get his 90 extract, his great goal.

DISCUSSION

Mr. S. MITCHELL said he gathered that Mr. Rogers did not obtain as good an extract when brewing strong beers as when brewing those of lower gravity. If he used a 20-quarter mash-tun and filled it completely, he appeared not to get as good an extract as if he carried out a mash of 15 quarters. If that were so, was there not something wrong with the construction of the mash-tun?

Mr. JOHN HOWE inquired whether it would not be better, in order to get the full extract in brewing a strong beer, to ensure us far as possible an even medium temperature in mash, and give a longer boil.

Mr. E. F. GODDARD asked if extra sugar would not facilitate a larger extract, provided the capacity of the wash-tun was small.

Mr. GEORGE PEARSON considered that it was more likely that the full extract would be obtained by mashing 20 quarters in a mash-tun made for 30 quarters. He could not see that loss in, extract meant an actual monetary loss; thus: the extra beer obtained from a malt yielding 87 per cent, extract over one yielding 85 per cent, was saved in the latter case on the duty.

Mr. W. H. LINLEY thought that quite as good an extract was obtained without rakes as with them.

Mr. JOHN HOWE referring to the question of temperature, said it was well known that a better extract was obtained from a malt at a low mashing temperature than at a high one. He thought, however, that when a high extract was obtained under such conditions the attenuation would run low, and a thin drinking boor be the result.

Mr. MOODY asked whether pressing or sparging was the better method to obtain extract from spent hops.

Mr. ROGERS, in reply to Mr. Mitchell, said if a mash-tun were filled up entirely and the boiling were only of one length, loss of extract must ensue; this showed the benefit of rakes. He quite agreed with Mr. Mitchell that extra head room in the mash-tun would give a chance of a better extract. Boiling in two lengths would secure a full extract; this would also answer Mr. John Howe’s question. In reply to Mr. Goddard, he would say that extra sugar must naturally relieve the strain on the mash-tun, and consequently benefit the extract. He would point out to Mr. Pearson that with increased extraction he would certainly have to pay 6s. 9d. on each barrel of beer at 1055 obtained, but he could sell those extra barrels of beer at, say, 36s. per barrel. In regard to the question of rakes, it was possible to get as good an extract without them, as Mr. Linley had suggested, but they formed a means of regulating a mash, and often of securing and mending an extract which otherwise would be poor. The lower the mashing temperature the higher would be the extract. It was therefore advantageous to employ us low a striking heat as was compatible with the production of a sound beer. In reply to Mr. Moody, he thought that more extract was obtained by sparging hops than by pressing them.

Mr. JOHN HOWE, at the instance of the Chairman, proposed a vote of thanks, which was seconded by Mr. George Pearson and carried unanimously.

Mr. ROGERS having replied appropriately, the proceedings terminated.