WATER SUPPLY FOR BUTTER FACTORIES

New Zealand Times, Volume LXXI, Issue 4407, 13 July 1901, Page 5 (Supplement)

WATER SUPPLY FOR BUTTER FACTORIES

(By H. W. Potts, F.C.S.) (Paper Read Before the Victorian Dairymen’s Association.) In this work I have received invaluable assistance from Dr Cherry, particularly in the direction of interpreting obscure phases associated with microorganic life; We are daily becoming more conversant with bacterial invasions during the manufacturing processes in our butter tirade, most of which have some determining influence on quality and keeping properties. Long distance from market is forcing us to adopt the system cf pasteurisation, Ip this process the object is to destroy, or eliminate as much as possible, existing micro-organisms in tlje crean}, and subsequently cultivate special species to oreat e defined fermentative changes by which a uniform character may be imparted to the finished article; hut in the. course of manufacture we are compelled to wash the butter, and we do sc. with water frequently infested with the identical organisms which were found in the pasteurised cream. This points to the need for constant vigilance in watching the water supply. Apart from this, where the ordinary practice of butter manufacture is conducted it is equally urgent that pure germ-fre e water shall bo used to wash butter —prior to the ordinary operations on the worker. The more our manufacturers become familiar with this class of investigation, the more definitely will we be able to deal with many problems our increasing trade is constantly bringing into prominence. The source of supply, its environment and conditions vary considerably. In some instances a roof supply is the only one available; and that is not always permanent; again, we find water ‘ utilised direct from open streams, lagoons, dams, irrigation channels, wells, reservoirs, etc., a bacteriological examination cf which give constant evidence and warnings of the absolute need for some system of filtration at many of our factories. It has to be noted, however, that in many districts the water supply is of the purest character. All surface waters, iu varying degree, possess some odour, arising from the presence cl organic matter through decomposition and by the presence of Jiving organisms. Many forms of filtration have ben adopted in the past—most of them being more or less defective, and often useless. The introduction of HIGH PRESSURE FILTRATION has placed in our hands a means of dealing with our water supply effectively when intelligently applied, and in this connection we cannot be too highly impressed with the constant need to h B on the alert in determining the true nature of the process. Th e conditions which obtain in filtering wafer on a large scale demand this. Many cf our factories are being supplied with high pressure filters with excellent results, and, as a practical example, I am permitted to quote the experience gained at the Korumburra butter factory in South Gippsland, and related by Mr Wilson, the manager. He states under date 22nd January: “We made about 400 hoses of butter which was washed with unfiltered wafer, and it turned out unsatisfactory, but in the same boat was a similar quantity treated with filtered water. The commercial result in London was a difference of £75, or 3s 9d per box in favour of the latter. At the tim e of manufacture one 661 b box of each was stored in our cool chamber at the factory. To all appearance in condition, flavour and aroma, both hexes Vfere equal. A weekly test was taken with ;Jhe trier in the presence of the directors, with the following results: “Seven days after manufacture; Washed with filtered water, good ; unfiltered, good. “Fourteen days after: Washed with filtered water, good, unfiltered, slightly off, moulds showing on the parchment. “Twenty-one days after: Washed with filtered water, good; unfiltered, flavour in the centre or the box slightly off, near surface off and bitter.

“Twenty-eight days after ; Washed with filtered water, good; upfiltered, flavour bitter and off, parchment freely marked with moulds.

Forty-two days after: Washed with filtered water, good; unfiltered, bitter and 'off flavour more pronounced. Fifty-six days after: Washed with filtered water, flavour slightly off, but passable, no sign of mould; unfiltered, very mouldy, condition rank, very bitter flavour.

The battery filter used in this instance was the “Abott.” I tested the water at the factory, and found in the ordinary unfiltered supply 6300 organisms in every cubic centimetre, or about sixteen drops. This water, when passed through the filter at the rate of 40 gallons per hour, gave a return of 280 organisms per cubic centimetre. This filter gave sufficient filtered water *o treat H tons of butter per day. Seve-

ral serious faults recorded against our butters in London may justly be charged to bacterial or mould invasions admitted through an impure water supply. Another form of filtration may be easily applied in outside districts by THE USE OF SAND. There is nothing new about this idea, seeing during the years 1886 and 1887 it was shown that, with a proper system, of sand filtration, then adopted by the London Water Supply companies, the number of micro-organisms were reduced from 96 to 99 per cent. In another Gippsland butter factory where the output had deteriorated, an investigation was pursued to - ascertain the cause of a peculiar stale flavour very pronounced in the butter. I found that, owing to tho dry season, the usual roof water supply had failed, and the water used for washing the butter was taken from the same source as that for the boiler, viz., an open dam in the factory yard. This was fed by a drain leading out of a morass or swamp. In this swamp the cattle from tho adjoining farms had collected to secure the only succulent food available. Samples of water wfero collected from the drain and the dam, and the subsequent plate cultivations made at the factory exhibited as many as 9000 micro-organisms per cubio centimetre, tho majority of which were colon bacilli or foecal bacteria, The milk supply and condition of manufacture were good at the factory, but in tho water alone was the origin of the peculiar fault in the butter. A 400-gallon tank was procured, a tap soldered in, and clean, well roasted gravel, ranging from the size of a walnut to that of peas, was gradually filled in, and on the top laid one foot of clean fine sand, well roasted. A flow was arranged into tho improvised filter. After 48 hours the water was found to be clear. A plate cultivation showed only 118 bacteria of a harmless kind per cubic centimetre, with ah entire absence of the hostile or stale flavour producing organisms. This filter gave 240 gallons of pure water per day. Where this method might bo permanently employed, a further advantage could be secured by having a brick and cement open tank exposed to th e germicidal action of sunlight, and _ the quantity to be filtered daily determined by the area. When the water i» stationary and shallow, the further aid of sedimentation is gained. Koch maintains that the slimy surface to the filter bed is where the organisms ar 6 arrested, and effectively prevents them passing through. Necessarily the flow for the first few days is not quite free until the slime has been formed. In many filters the bed of sand fias been laid 3 feet thick, after it has been thoroughly cleansed and roasted, and passed through a 40 mesh to the inch sieve. This has been known to act as a barrier to the passage of organisms for three months. When they are found to gradually grow through and reach the filtrate, a renewal of roasted sand is then required.

OTHER ORGANISMS, apart from bacteria, and known under the generic title of infusoria, produce distinctive odours. These are grouped under three general t e rnis of fishy, aromatic and grassy. Wo find these microscopic organisms in our dams and streams. Under either process of filtration it is essential that a regular number of tests he taken to determine its effective character. IKoch’s test enables us to make plate cultivations of a known quantity of water, to develop and count the number of organisms which exist in it, to identify the different species and characteristics and their effect on the manufactured article. If any time elapses between the taking of the sample and its subsequent examination, particularly in warm weather, it is impossible to accurately estimate the number. They increase so rapidly. The method of manipulating the test is readily learned, and I have had encouraging results from several pupils in our factories, so much so that I intend to include it in our curriculum. When the plates are inoculated they are sent to the laboratory for examination. A report is forwarded giving the quantity and character of the organisms, their functions and requisite advice. This is a subject which seriously affects the welfare of our industry, and it is brought before this association with th o object of directing attention to th e great importance of providing efficient means of dealing with the water supplies at our factories. IMPROVED BUILDINGS.

Tho attention of directors and owners of factories is directed to the stats of mnny of our factories. Originally built qf wood, with wooden floors, and frequently with a very inadequate _ conception of what is needed, the original buildings haye become too small; the walls, floors and ceilings are showing evidence of inicrobic disease, particular-: ly in those qream ripening rooms where light and ventilation are absent. The result is the manufactured article depreciates in value. Our industry has suffered, and is suffering, through the employment of enthusiastic amateur architects and engineers. Errors of construction, the flagrant disregard of sanitary precautions, and the want of knowledge exhibited in providing suitable buildings and appliances are constantly in existence. The value of this industry depends on our keeping pace with our trade rivals, and in doing SO We must he provided with modern buildings and equipment. The period allotted to wooden factories is rapidly drawing to a doge, and it will he a wise act for boards £o make provision for rebuilding their factories on modern lines at an early date. Ileserva funds for this purpose should be opened, and the position faced for carrying cut such improvements as are demanded by the keen conditions for a higher quality product.