342 PROCEEDINGS OF SECTION G. 
PASTEURISATION. 
Recognising existent dairying conditions, in which the intro- 
duction of numberless organisms to the milk, including yeasts 
and moulds, are all provocative of tainted flavours, and retard 
ihe development of keeping qualities as well as good taste; it 
is a question often asked—Ought we not to adopt pasteurisation ? 
and the answer is Yes. The principles underlying its applica- 
tion are readily grasped. 
The separator removes a large percentage of organisms, and 
ihe remainder, which are so liable to induce abnormal fermenta- 
tions and changes in the cream, should be destroyed by means 
of the admirable pasteurisers now in use. These are so con- 
structed as to reduce the cost of pasteurisation to a minimum. 
After cooling, the cream must be impregnated with selected 
families of acid-producing organisms, which set up the fermenta- 
tion needed to impart desirable acid, nutty flavour, waxy tex- 
ture, and durable keeping qualities. On the purity and selec- 
tion of the cultures, and their suitable treatment, depend the 
butter-maker’s ability to provide his customer with any flavour 
er aroma he may demand. 
At many of our factories indigenous “ starters” are developed 
from the daily supply of buttermilk direct from the churn. 
These undoubtedly give good results, but their use is empirical. 
No assurance is obtainable under ordinary conditions that un- 
desirable bacteria, yeasts, or moulds are not present. No cer- 
tainty of purity in the culture is assured. When examining 
buttermilk “starters” at our factories we have occasionally 
identified foreign invasions, all of which may impart to the 
butter objectionable taints and flavours, or “ fishiness.” In one 
case we found a free growth of Bacillus prodigiosus, a red 
organism. 
All factories or butter-makers should aim at securing a pure 
culture from which to make the starter. It is the most cer- 
tain, effective, and reliable. 
With a vigilant regard for the principles associated with 
pasteurisation, no contaminating influence can prevail or inter- 
fere with a constantly uniform manufacture of good butter. 
ImMrorTED PuRE CULTURES. 
The Department of Agriculture imported direct from five of 
the principal laboratories in Europe a number of so-called pure 
cultures in powder form, also a few from America. These came 
to hand at regular intervals during a period of twelve months, 
and were submitted to practical tests as well as bacteriological 
examination. Our experience with them went to prove that it 
is difficult to import and ensure a pure supply. In fact, there 
is no certainty about the purity of the cultures. 
