BY-PRODUCT OF MILK.

New Zealand Herald, Volume LX, Issue 18411, 29 May 1923, Page 8 (Supplement)

BY-PRODUCT OF MILK.

MANUFACTURE' OF CASEIN.

SUBSTANCE .OF MANY USES.

The most remarkable by-product of milk is casein. This commodity which is manufactured from milk from which the butterfat has already been extracted, -is used as a substitute for bone, horn, ivory, celluloid and porcelain, as a glue, as a adhesive agent in paint, as a glazing material, as a waterproof skin /for paper asbestos etc., as an insulating -'' material and in the manufacture ;of leather and linoleum, as a substitute for eggs in baking, and as a constituent in face creams, soaps, etc. ' It was first manufactured in New Zealand in 1913 by the New Zealand Dairy Association in' a factory, in Frankton but the war disturbed plans and interrupted manufacture; - Since the war ended production of casein in the Waikato has increased to about 1000 tons this season. The increase has been rapid and in view of the fact; that this;"season an inquiry for 200 tons could not be met, there is reason for believing that a very much larger output will take place next season.

The output can be s expanded/to a very great extent without an expansion of the whole industry. On an average two and half pounds of ; casein can be obtained, from 100 pounds of skirn milk. Of course- home separation does - : not permit ;of the manufacture of casein. The whole milk must be delivered at . a -precipitating ' station but there can be no doubt that the collection; of ■ sufficient milk to meet all demands : for casein could be arranged provided a profit can be shown. '■;'■? /,. . The production- of casein does not involved very intricate process.v. The first step'takes place in the creamery to which the • milk has-been, delivered. The skim milk which is accumulated in huge vats .is ;.changed , into -curd by. the introduction •of! a starter " of, : lactic ' acid, .cultures. Here .trouble is sometimes': encountered. An exact temperature must be maintained andthis is; hot usually ; a.-difficult matter but ■ il',. the smallest proportion ;. of ' the milk has been ; tainted, ■a ; ferment sets up* ,which ;may spoil the whole vat.. Occasionally feed taints -have' the same effect-.' .

-;> (When the vat lias set into a firm curd the ordinary ' type of curd Cutting knife is: drawn through it to divide....the;_sub-. stance into small cubes. Steam heat is then applied and the whey, is run off. In the shape of " cheeses " the curd is transported to the central factory. There it is broken up and baked in ovens on travelling racks to thoroughly dry it. It is then ground ' into powder which is riddled into three grades and packed for export. , It has been argued that New Zealand should follow the example of Australia' and manufacture the casein into various articles. In the Commonwealth buttons, imitation ivory- and billiard balls are made from the by-product. No process is neccessary for the making of casein glue, the addition of a certain quantity of water being all that is necessary. But there are many directions in which casein could form the basis of new industries, provided a sufficient sale could be obtained for the manufactured articles. Whether the future will witness new secondary industries developing around the manufacture of casein is only a matter of surmise. The fact which counts at the present time is that with the utilisation of by-products the .scope of the dairy industry is widening. New, fields are being exploited and fresh possibilities are arising above the horizon. Thus a sense of security is growing up in the business that is not usually [ associated with rural "pursuits. Every new venture is not likely to be a success but in industry, as in private affairs, it is a good thing' not- to have-all the eggs in one basket.