This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol6", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
(Contributed by Hedley C. Queree)
Great improvements and changes have taken place in dairy construction and fittings since the days when the cream was separated from the milk in a rough and ready method, and then placed in open pails to ripen till a sufficient quantity had been acquired to churn into butter.
Within the last few years all dairy appliances have been brought to a state of great perfection, both those worked by hand and those by machinery. The method of working both of these systems is practically similar.
By way of introduction it may be well to follow the process through which the milk is taken in an ordinary dairy of reasonable size. To render this general explanation quite clear, a diagrammatic view of a modern creamery is given in Fig. 86. The motive power is supplied by a boiler and engine, which are placed preferably in a room apart, and to which admittance should be obtained from outside, and not through the dairy.
Diagrammatic View Of The Mechanical Equipment.
Of A Modern Creamery By Loudon M. Douclas.A.M.I.Mech.E.
The milk when brought in is measured, tested, and, if found satisfactory, tipped into a tank on a raised platform, from which it flows into a Pasteuriser. At this stage of the process the purpose for which the milk is required has to be considered, whether to be sent out as milk or else to be turned into cream and butter. If for milk supply the milk is driven from the pasteuriser, where it has been heated, over capillary coolers, one cooled with cold water and the other chilled with brine; one cooler or both may be used as is required. The milk thus chilled flows down into a tank, from which it is drawn into cans used for the daily milk rounds. For butter making the pasteurised milk is run into a Separator, where the milk fat or cream is separated from the milk. That which is left is called skimmed milk, and is either run into a tank straight away, where it ferments, or else goes through to the intermediate stage of being chilled over a cooler. This milk is, as a rule, sold to farmers for feeding pigs, and it depends on their requirements whether the milk is to be chilled or not, but provision should always be made so that this may be done if required. The cream, when separated, falls over or is pumped up to - according as to whether the separator is above or below - the coolers, where it is run over the first one made cold by a supply of cold water, and then falls over one chilled with brine. The chilled cream is then either pumped into a cream ripening vat, or else drawn off in pails and placed in troughs to cool by means of cold water. When the cream has sufficiently ripened it is run over a cooler into the churn, or else placed into the churn direct, where it is rotated till it is of the consistency of butter granules, when it is taken out by hand and placed on the butter working table, is there kneaded and salted, and taken to an ordinary table where it is weighed and packed up. Here the actual making is at an end, and the butter is ready for sale. If to be stored, it is placed in a cool chamber or in a cold storage room. With modern churns and butter-workers every particle of milk fat is used for the butter, so that the liquid - known as butter milk - is of so poor a quality that it is usually run to waste.
Where it is required to have cream for selling purposes it is customary to place the milk, in pails, into a concrete trough, where hot water is first of all turned on, so sterilising the milk, which is subsequently cooled by filling the trough with cold water. When the cream has sufficiently ripened it is cut off and sold, the remainder being sold as cheap milk, there being still a certain amount of fat in it. The width of trough will naturally be made to suit the size of whatever milk pail is in use by the dairyman for whom the dairy is to be constructed.
Washing troughs are an important point in dairies, and are made in number and size according to the peculiar requirements under consideration. Each trough should be in two compartments, one for washing out pails with cold water and the other for scalding with hot water.
It will be noticed that some of the principal requirements for dairy purposes are ventilation, cleanliness, and a very good supply of both cold and hot water.