THE DAIRY.

New Zealand Mail, Issue 1354, 10 February 1898, Page 4

THE DAIRY.

PABTEUBIBINB IH VICTORIA Pasteurising at'Euroa Butter Factory is described in the following terms by Mr Potts the well known Viatorun j chemist and pasteurising expcr'. “The j long and exhaustive series id >x t »M mental tests conducted at the above company’s factory in pasteurising dut’ ing the past two years have afforded ample practical evidence of the value of the system, and justified the directors in adopting it on a larger scale. In fact, it has been decided to pasteurise the whole of this factory’s output as soon as the requisite plant can be installed. The new Pausch pasteuriser, at the central factory, is proving a success, and it advantages over the ones previously used are obvious. Less steam is used and the heat is more readily controlled. The working parts are all movable, and afford every facility for keeping the plant in a thoroughly sweet and clean condition. Owing to the peculiar make of the stirrer and the fan or turbine under it, the cream is driven by centrifugal action to the outlet at the top, and if required it can be elevated by this mo* | tion fully 9 feet. This machine can

1 kfcep pace in pasteurising the cream from two full sized separators arid acts simultaneously with them,, and requires very little attention from the man in charge. The temperature may be allowed to vary more than with milk, and if a range of from 160 deg. Fahr to 170 deg. Fahr. be preserved, this effects good results. From the pasteuriser the cream is pumped hot into the receiving vat, and then passes direct over the De Laval coolers. From there it teafiheg the ripening tanks cooled down to 55 deg. Fahr. 1. may mention tliat this is the process at the factory* whetO skimming, pasted rising arid cooling arfl ail conducted in rapid dotation.” “At the creameries* says Mr jtAtts, “ this canriot be dotie, thdugk cream is Conveyed straight from the pasteurisers to the cream can hot* the lids affixed and brought into the central factory in this heated condition. On arrival we find the temperature is reduced by about 20 Fahr, but in all cases it arrives in excellent condition, sweet, sriiodth, and even, with uorcdal acidity present. It is then passed tiver the De Laval coolers in thd sadie way as the factory cream. When the cream vat is full it is impregnated with a suitable culture or starter to ripen it, and develop the requisite acidity, aroma and flavor, A starter is usually prepared by selecting three gallons of sound* new milk selected from a dairy noted for cleanliness and good milk. This is pasteurised at a temperature of 180 deg. Fahr., after which it is rapidlycooled down to 85 deg Fahr., then Chr. Hansen’s dry lactic ferment is in troditced and gently stirred. The impregnated milk is kept at the same temperature of 85 deg. Fahr., or thereabouts, for 18 hours, when it will be found in a coagulated condition. It is now ready for the pa3teurated cream, but first must be lowered to a temperature of 55 deg. Fahr. or. the same as the cream. Mix this with five gallons of the cream, stir gently and allow it to stand 15 minutes, then add to 55 gallons of cream, making a total of 66 gallons, followed by ripening in the usual way. The starter or culture is propagated from day to 4ay by adding from 2 per cent to 5 per cent, of each day’s starter to freshly pasteurised milk as conducted in the first operation. In this way the same families of bacteria are propagated day after day until on examination it is proved to be weakened or is assuming a changed nature, then it is necessary to commence de novo, and prepare a fresh culture, from the dry lactic ferment. Much disappointment may accrue in the preparation of a new culture, seeing good results are not always assured, and it has been proved that two, three and even four cultures had to be abandoned through some condition varying, or slight neglect in detail. Great precautions must be taken to prevent the invasion of unfriendly germ life, and to retain in healthy condition those we fin l convey to butter the desirable acidity, aroma and flavor. These cultures’need daily attention and great care, as on them, to a large d-.gree, depends the market condition of the butter. One special precaution must be observed. All vessels used for preparing culture, or brought in contact with them, as well as the ripening vats, must be regularly sterilised, or rendered germ proof by boiling water or steam. The butter made from pasteurised cream is . unquestionably superior, and the losses arising from inferior cream brought in during hot weather effects considerable savins.