LECTURE ON BUTTERMAKING.

Otago Witness, Issue 2310, 9 June 1898, Page 14

LECTURE ON BUTTERMAKING.

AN INTERESTING DISCUSSION.'

In connection with the winter show a lecture on ".Factory Butter-making " was delivered in the Chamber of Commerce Hall on Thursday morning by Mr O. R. Sorenson, Government dairy instructor. Mr James Milne, president of the National Dairy Association, occupied the Bhair, and about 25 or 30 persons were present.

Mr Sorenson, in his opening remarks, said lie proposed only to deliver such a lecture as would serve as a peg for.* discussion which might follow, running over the main points. It might be as well at the outset to describe what class of butter was wanted for the London market. What was required was butter of uniform character, rfot only as between one box and another of any particular shipment, but uniform ~ also as between ona shipment and another, and as between one season and ■ another. Of .the different characteristics which went to make up a good i fcutter, the most important was the flavour, which must be perfectly sweet and "clean," j not insipid, but " nutty " and aromatic. The j butter must be absolutely free from buttermilk or any discolouration of the moisture, and | •hould not show excess of moisture. The body should be firm and capable of standing considerable warmth without melting. The texture should be close and waxy, not brittle, and the colour should be perfectly straight and be free from streaks or mottles. Finally, the package containing the butter should be as attractive as it possibly could be made. To make perfect butter fulfilling all these requirements they must have perfect milk. The education of the milk supplier in that respect must be accomplished by more than a lecture. Ho lesson would make such an impression on him as having his milk returned once or twice or as often as need ba from the factory. Though that lesson should ba administered as firmly and as often as need be, yet they must cot forget the lecture, for in roanv cases* the faulty condition of the milk was due to ignorance se much as to carelessness. The lesson, moreover, should be administered courteously as well as firsily, or otherwise the supplier would imagine that it was done oat of ill-will. In the condition of the milk as it was brought fco the factory lay the foundation of all success in butter-makiDg. Every can should be carefully examined before it was accepted, for one can of bad milk would depreciate the value of the whole day's output. Yet:, how often was the important task of weighing in the milk deputed to »n irresponsible assistant — sometimes a mere boy ? If the assistant wss well trained • and reliable there was no objection to his being given tbe work, but as a general principle the man who was responsible for the quality of the output should personally undertake the task of weighing in the milk. In some factories in Australia and America every can of milk was submitted to- an acid tesfc,-rnade by means of alkaline 'tablets. ' The test might be made so quickly as not to delay tha weighing in of the milk at all. Two vats were provided, and, to save time, two faucets were attached to the weigh can, and anything showing 100 much acidity, while not too bad altogether, was run into tbe second vat and treated separately, the suppliers being paid a lower price for any milk so treated. in some districts <Sf New Zealand it was almost Impossible to secure the delivery of milk in good condition, this being owing to the cows eating weeds or foliage, or to dirty treatment of the milk, or to neglect to cool the milk immediately after milking. Whore the fault wss ona that could be overcome by better treatment of the milk, the remedy consisted in refusing to accept all such milk. He admitted that that was an unpleasant duty — he knew it well, for once he had to send back 300 out of 700 gallons to bring some careless suppliers up to the scratch, and he was anything but blessed.. The directors of co-operative factories were under a bounden duty to uphold their managers in refusing such milk, bub in some cases the directors were the worst offenders. In euch cases one could hardly blame the manager if he exercised caution in falling out with the powers that be, but sfc the same me if the manager only took a firm stand and refused bad milk from whomsoever it ct-me, he would, the speaker believed, gain 'the respect of the very men he feared to~offend. In connection with the eubject of inferior milk, i 'the' lecturer referred to the question of pasteur- ' isation. It was not to be imagined that, with the, aid of pasteurisation, perfect butter might;.. be produced from bad milk. Evea with pasteur- j isation perfect butter required perfect milk, but pasteurisation overcame to a very great -extent a. certain amount of acidity in the uailk, and would eliminate taiu,ts of weed flavours. Wherever flavours were at all defective pasteurisation was to be recommended, always subject to the conditions that there were a proper pasteurising plant available, ample cooling -power, and intelligent preparation of the "starter" and care and judgment in the ripening of the cream. Given these conditions, pasteurisation might be safely undertaken ; but where the flavour of the butter was good, scor-

ing, cay, M or 42 out of a possible 45, or where these conditions were unattainable, it might be as well to bide ss they were. He was in favour of pasteurising the whole milk prior to separation rather than of pasteurising the cream, because by separating at a high temperature they could" skim very much cleaner ; indeed, they conld extracti sufficient f xtr* butter-fat — that, by separating at 80 to 90, would reiaain in the ekim milk — to pay for the expense of Ihe process many times over. Pasteurisation of the whole milk reduced the quantity of fatty acid? in the butter by 75 per cent, while pasteurising the cream only reduced the amount by 35 per cent., and as it was mainly due to the presence of these fatty acids that butter decomposed, it followed that a better-keeping butter might be made by pasteurising the milk rather than by pasteurising the cream. Supposing that all the milk was weighed in at the factory, and that all the milk in the vat was good milk, it had to be separated, and the essential points to ba observed were — the temperature of the railk, the regularity of the feed, freedom from vibration of the machines, and the speed of the separator bowl. 'With regard to the firs!; of these conditions, it mi^ht be laid down that, other conditions being equal, the higher the lemperi.to.re of the milk the better would be the skimming. Irregularity of feed would cause a variation in the richness of the cream and loss of fat in the skins milk. A diminution in speed produced the same effects. The capacity of a separator incceased or decreased in proportion to the square of the velocity at whish the bowl was running, and consequently a slackening in speed reduced the efficiency of the machine. Vibration counteracted the centrifugal force and caused loss of fat in the skim milk. In summer, and especially where cream had to be carted long distances by road or rail, the separator should be set so as to skim fairly ! thick cream, containing, say, 40 to 45 or even 50 | per cent, of butter fat. Some operators ran | their cream off far to thin in order to gat ! through mora quickly, with the result that they had* a lot of extra bulk to handle — they encouraged the development of acidity by leaving an excess of casein in the cream, and they would probably find white specks in their butter. If the cream had to be carted, it would churn in the cans and be a fruitful source of loss and low-quality butter. In cold weather it was permissible to run thinner cream, for there was then less danger from theae causes. Immediately after separation the cream should be cooled in order to expel the air bubbles forced into it during its passage through the machine and to solidify the liquid fat globules. Unless this was done and the temperature was reduced fco at least 55deg, the butter suffered in body, and a loss took place in tho buttermilk through the non-solidification of a portion of the fat globules. The Dines were very particular about this, and insisted that the cream should be cooled to as low as 45deg,' kept at that for an hour or so, and then re-heated to ripening temperature; It must, however, always be remembered that tbe chemical composition of the fats varied in different localities and at different periods of lactation, and that what might be necessary in one district was not in another. His own experience went to show that as a rule it was advisable to cool the cream after separation to at least 553 eg. With respect to the j ripening process, the lecturer pointed out that i some eight years ago a Danish chemisb named ! Storch discovered that tha flavour in butter, was j largely due to bacterial influence, and that by j inoculating cream with a pure culture of & certain j species of bacteria a flavour of exquisite aroma conld be imparted to the butter mads from such cresm. Owiug to these discoveries the process of cream-ripening had been reduced to | a science. It consisted airaply in the cultiva- i tion of the desirable and tha elimination,- or at i aDyrafce the overpowering, of the undesirable j bacteria. It was in regard to the elimination ! of the undesirable bacteria that pasteurisation afforded such valuable assistance, destroying all the bacteria present — good, bad, or iadiffereut, — and leaving a clear field in which to sow »cd cultivate the particular species fch&t would produce the recognised flavour. But whether-they pasteurised or not, the cream naugi; be ripened, and ripened evenly from day to day, .prelse it would not noa-ka uniformly-flavoured batter. If the cream was simpiy left to itself, the undesirable' germs, some of which were always present in factory milk, might get the upper hand over the good germs ; or, even supposing that none but good germs were present, the temperature on which bacterial development mainly depended might be too high, and in that case the cream would be over-ripe before they were ready to churn ; or the temperature might bs too low, in which case churning time would find the cream only half-ripe. To gain uniformity they had to regulate the conditions so that the ripening of the cream would be independent of weather and outside influence. In the first place, they must have as few bad germs as possible in tha cream to start with, and that necessitated watchful attention fco the condition of the milk, pasteurisation, and scrupulous cleanliness at all stages of the cream's handling in the factory! Theu they must introduce into the cream a culture of such desirable bacteria as would produce a flue flavour, and by regulating the temperature they enabled them to develop quickly and gave them » numerical advantage over any undesirable ferments that might have gained access. Personally, he was in favour of ripening cream quickly — that was, within 24- hours, — for the slower the develoo-

meufc of the lactic acid bacteria the better chance undesirable immigrants had of surviving, while .on the other hand, the shorter the time of ripening the less risk there was of contamination from outside sources. The period of | ripening depended on two things — the condition 1 of the "starter" and the judicious regulation of the amount used and of the temperature maintained. " Starters " were of three kinds — sour butter-milk from the previous churning, in which case care must be exercised to see that there was no stale or "off " flavour ; fresh milk or skim milk, either pasteurised or not and Allowed to ripen naturally ; and pure culture or lactic ferment of commerce, which was the most uniform, and possibly the simplest, of all, and with which, if the directions issued with each bottle were rigidly adhered to, good results conld generally be relied on. Commercial " starters" would not keep good for more -than three month?, bub he saw no reason why the Dairy Association, if it was a live association, shcutd not arrange for the regular despatch of fresh supplies hy" each mail steamer just 1 as veterinary surgeons now got regular supplies of tuberculin. The acid test to which he had .referred was a useful adjunct in cream -ripening and should be found in every factory, as by its ' aid they were able to gauge the development i i of ar-idity in the cream and hasten or retard it j where it was desirable. Ripa cream should coni tain between *5 and '6 per cent, of lactic acid. The test would, of course, indicate only the amount and not the kind of acidity, the latter point being gauged by the taste, smell, acid appearance. The characteristics of well-ripened cream were a glo-sy smoothness like treacle or white oil-paint, a mild acid but not bitter taste, and a sweet, clean, aromatic smell. Cream should be cooled down at least half an hour before churning to the proper temperature. No hard-and-fast rule could be laid down as to thig, but under average conditions cream should be churned »i s-boat 50 to 52deg. in summer, and at 52 to 54-deg or even 55deg in winter. Churning above these temperatures resulted in a loss of butter in the butter-milk. It might be urged that the difference between the fat concents of butter-milk churned at 55deg and that churned at 50deg might be too small to compensate for the trouble of cooling the cream the extra sdeg ; bub it must not be forgotten that the butter waa far more easily freed from butter-milk if ohurned at the lower temperature, and less washing would suffice. Churning should be stopped when the graaules were the size of pin's heads, li tha cream was all of equal ripeness all the fat could be extracted at that stage, and to go beyond it was simply to injure the texture of the batter. With regard to washing the butter, the lecturer insisted that th« wate* shonld be irreproachably pure, should never ba fallowed to lie in the tanks overnight, and should bo 2i3e.g or 3deg colder than the butter ; if the water was warmer the bufcfcer was rendered sticky, and if it was too col\l the butter became hard and brittle and difficult to work. The object of washing butter was to remove the butter-milk, but as it also removed the aroma which it was desirable to preserve, they should strive to raiaimisa the washing, and the best way to do ' that was %o ehuru at % low temperature. In salting butter 'they should use only the best salt, and they should vary the amount of salt in accordance with the amount of moisture in the butler — the finer the granulation tha more moisture would the butter retain. In working butter the main thing' was to avoid friction or sraeiring. Some colonial bufcter-m&kers simply spoiled every pound of butter worked by them because they rubbed and did not press the butter. At the first working the aim should be solely to mix the salt evenly and make the butter cohesive. The aim of ibe second working was to expel the moisture, and this should be undertaken as soou as the calt had had time to rfissolre thoroughly and the butter to regain ita firmness. With refrigeration this could be accomplised in two or three hours, but without it it was besfc to leave the butter overnight and rework it firot thing in the morning; before it got warm. The lecturer concluded by giving some general hints for buiitei -makers. He advised them to rinse all their utensils, vats, churns, and butter tables, and also their drains, and, in fact, everything about their factory, with lime water, which was the best and cheapest disinfectant imaginable and the safest to use, and he gave them instructions in its preparation. They should, he continued, never allow cream to lie in tha churn for anytime before churning, as the acid got into the pores of the wood and made it almosfe an impossibility to keep the churn sweet. Ho had found in some factories last season that the cream was allowed to lie in the churn overnight to save the manager trouble in the morning, and he strongly condemned the practice. Then the churn should never be allowed to lie overnight with ordinary water in it. It should either be scalded thoroughly with boiling water and allowed to dry, or else it should be left full of lime water all night, in which event no scalding would be required in the morning, and, above all, after the limewater had been run off ib should not be rinsed out with ordinary water. A composite test of the buttermilk should be kept just as it w»s kept of the suppliers' milk every day, and similarly with each separator that was in use. In testing they should see that their machine w*s driven up to specd — the periphery of the bottles when extended should travel 4500 ft per minute. They should turn the machine for five minutes the first time, two

minutes the second time, and one minute the third time. They ihould use boiling water, and keep the testa hot while the readings were being taken. When testing skim milk they should use one-third to one-quarter more acid than for whole milk, and should turn the machine at full speed for five minutes.

In answer to a question, Mr Sorenson said ili was almost impos»ible for any man to say what was the cause of a " back " in saltsd butter.

Mr J. T. Lang said the question had arisen several times about moisture in butter. It was said that by putting moisture into butter to a certain exteafc we were not transgressing the law, and yet the weight of the butter was considerably increased, and he asked Mr Sorenson how thu-t could be successfully done.

Mr Sokenson said that question was very much under discussion last seasoa. There were certain buyers who came out to the colony and said that the butter might be adulterated with j an extra. 5 per cent of water, for that was what ] it amounted to. That was contrary to all past | experience, which was that the drier the butter was the better the London people liked ifc, and he was not going to advocate < the putting of more water in the butter.

Mr J. R. Scott, s-s a buyer, thought it would bs most undesirable to give instructions to people to adulterate bufcter with water or anything else. As a buyer he wanted to buy butter ; he could get water or anything else- | where. — (Laughter,) j Mr Lang said he did not want to adulterate the butter, but they had been told that a certain amount of water in butter was admissible. Some of the best butter th&t left the colony contained a email percentage of water, and a butter that showed a certain amount of moisture in the trier did not contain so much moisture as another butter, and yet the latter was tried perfectly dry. Mr A. A. Thornton icquired where the butter was analysed.

Mr Lan<j said the butter was taken straight from the grading stores at Poet Chalmers and tested. He did not say that the test was thoroughly reliable, but the butter that showed the least moisture was the sloppiest of the lot, and that which showed most moistnra was the driest ho had <-,ver seea in New Zealand.

Mr Thornton said he did not care how much moisture there was in the butter so long as it did not show in the trier.

Mr Johnston said that if tliey could add 2 per cent, more moisture to butter, aad yet not show tbat in tbe trier, if; would add considerably to tha profit* of the butter. Mr Scott said he would nob like it go forth that they were attempting to do that sort of thing in New Zealand. Ho thought it most undesirable.

Mr Riddeli thought it would be desirable if they could work at 12 per cent. The Danes worked afc 15 per cent, and the Irish at 20 per cent., and still the graders said here that there was too much moisture. It was not water at all that was seen in the trier, but is was the brine. •

Mr Sorenson said that when they talked of moisture in butter they meant" briae. He might say that a very simple way of adulterating butter by moisture was by working in warm brine. They could work it up to_4o per cent., and there were chemicals "by which they could make it contain up to 60 per cent, of moisture, and yet outwardly it would not ba very sloppy butter Danish butter contained an average of 14 to 15 per cent, of moisture, — in bufcter that was analysed from 680 factories in 1897 lowest proportion of moisture W3S 13 per cent., and the highest was 16 per cent., the average being about 14 per cent. — but this Danish buttsr did not show moisture in the trier. The moisture was incorporated in the butter in such a very fine emulsion lh?.t ife was not apparent, whereaa if ths brine drops were present in a large size— a large size, that was, under the microscope — they would leak, and the butter would apparently have too much moisture.

Mr Scott believed that ib was well understood at Home that the Danes would eventually have to lessen tha amount of the moisture iv their buttsr. He did not thiak tha buyers at Home" looked at it a* a* desirable point that there was so much moitture in their butter, and he questioned whether the putting of so niuoh moisture in the butter was not apt to kill the flavour. He hoped the valuable " tip " which Mr Sorenson had given as to working with hot brine would not be taken advantage of.

Mr Lang said that one of the finest butters leaving the colony from Port Chalmers — the batter of tho Taieri and Peninsula Company — right through the season shewed an excess- of free moisture, and what he wanted to ascertain was how that moisture could be retained in the batter without its being apparent.

Mr Sorenson said that a large number of experiments were being made in Denmark ju3t now with reference to that point, but no conclusion had yet; been arrived at as to how a large amount of moisture could be retained. It was shown, however, that when the moisture was present in the shape of a very fine emulsion its presence could not be detected.

Mr Riddell asked why lactic acid could nob be made in the colony so that it would not be necessary to import it.

Mr Sorenson said he communicated tome time ago with Christian Haneen and Co., the makers, in Denmark, to ask if they would start a factory in one of the Australian colonies, but they deolined, saying they had quite enough

trouble with the American factory that they had started. The making of pure cultures was a very difficult process, requiring an expensive plant, and we were not in a large enough way of business in the colonies to warrant works of that importance being set up.

Mr R.-W. Robertson asked if it was-not with the view of getting a drier butter that the Danish introduced pasteurisation. v Mr Sorenson did not think ifc was with that view, bub after pasteurisation had been introduced ifc was discovered that it was possible to make a drier butter.

Mr Lang asked what caused steakinesa (a butter.

Mr Sorenson replied that that was simply due to not working the salt iv sufficiently. Mr Thornton comaiented on the weighing of butter in the stores during the pa«fe season, and said* that in several canes he had found' that tho butter wa3 31b or 41b less in weight than thafe marked on the box, and in other cases tho weight was lib or l£'b more than that which was marked. There was one large factory in the Wairarapa district where ha understood tha practice was simply to pack the butter in the box, top it off, and pack it < fli to Wellington in a box that was market* 561b. He thought ifc advisable that every f actdry should look into the question of the weighing of butter. Mr Johnston asked what was the proper shrinking in £cwfc of butter. Mr Sorenson said his own opinion was that if the butter was properly made there should be no shrinking.

Mr Scott said the remedy was not to put too much moisture in. — (Laughter.) Mr Sorenson said they had had butter iff tha, Wellington cooling stores for three or foue months which was the same weight when ife came oufc an when ifc went in.

Mr Thornton : What is your opinion abonfi preservatives in butter? — (Lsughter.) Mr Sorenson eaid he had held the view that preservatives iv batter were undesirable, and he still held that vitw ; but in tho light of receufe expedience he admitted that bcracic acid had a certain value as & preservative. On the other hand people in the old country were complaining more and more strongly every day againsfi the adulteration of food products by boracic acid, for nofc only their butter bat everything they consumed jvas practically dosed more or less with boracio acid, and it was th# excessive amouut th&t they consumed in the aggregate that did the dam*ge. He believed that in the near future legislation would' ba passed in EDg!and,to prohibit the use of boracicacid, «nd he thought that . butter-makers in the colony should look that matter in the face and do without boraeic acid, or else limit its use to tha lowest possible extent — namely, Boz per lOOJb.

Mr Scott thought the use of preservatives was mare necessary in the olden days, when butter was not stored, and he believed ifc quits possible to make satisfactory butter without any preservative afc all.

Mr Riddeli, said hiß company had been in the habit of using 4oz of acid to 561b butter, and if a m*n ate lib par week that would mean he consumed '6 of a drachm at ncid, and ha asked if th&t would do him any hrvrra.— (Laughter, i Mr Sorenson said he had discussed the question of preservatives pretty fully this year in his annual report;, which would probably appear in the course of tbe next few months. The department last yea»- seat out circulars to fcha factories, from 30 of which .replies were received. Out of the 30 there were 18 factories that appeared to use no preservative* at all, sis; were in favour of their use, and the remaining six were neutral — they had either uob used them and could not say if.thay were beaefieenfc, os elsa had carried got experiments but been unable to come to any ac finite conclusion. Taking it oo & quantity basts, ho found that last aeasou 1500 tons of batter were rasde with preservatives, that amount iaclud* ing some of tbe very best butter that ieffc New Zealand ; some 1425 tons were made witho.ufe preservatives ; and of the butter tbafc was roado by the neutral factories, about 700 tons were not made with preservatives. Consequently the bulk of the butter that left New Zealand iv the pass season was not made wii& preservatives" Experiment)! were carried ont last season at Moturoa and Wellington, with tha result that- the batter that waa made with preservatives cams out a little better than that which was iiot so treated, and that result waa confirmed by the competition in the winter show at> Dunedin— the Taieri and Peninsula Company* exhibits, that were placed first, aecond, *nd third, having been made with preservatives, and tho3B that were fourth and fifth nofc having been made with preservatives.

Mr Riddeli. asked if Mr Sorenson did not think that if a proper -milking machine were brought into use it would" do away wifch the need of pasteurisation.

Mr Sorenson said that was so. Perfect milk- did not need pasteurisation, which was admittedly only a cure, and prevention' was better than sure. ' ~

Mr Scott, in moving a vote of thanks fco t&v Sorenson-, bore testimony to the good work bhwA was being done .all over the colony by iha Government instructors. ~ -

Mr Riddell seconded the motiori, and s,aid there was no doubt that the dairy instructors

Ethel K. Benjvmjn, Barrister and Solicitor, Albert Buildings, Princes street, Duriedin (oppoj Bite C.P.0.), has trastiaoueya to lend on approved security.— Ad vt.

jlad done an immense amount of good, and if they could be got to visit the farmers during the winter months (o instruct them how to giva the factories good milk, they would render a great service. The motion was carried by acclamation, and a vote of thanks was accorded also to the chairman.