SWEET CREAM FOR CHURNING.

Otago Witness, Issue 2921, 9 March 1910, Page 8

SWEET CREAM FOR CHURNING.

It has been a generally accepted theory among teachers of and writers on-dairy subjects that the production of good butter necessitates the development of a certain amount of acid in the cfeam; foi two reasons—to develop a desirable flavour and to improve the keeping utility. Recent investigations by the United States Department of Agriculture indicate, however, .that butter made from pasteurised sweet cream lias better keeping qualities and remainsfree from objectionable flavours for a longer time than butter made from sour cream. The dairy division of the Bureau of Animal Industry for the- last three years has been making a study of the change which butter undergoes in storage, and especially the influence of acidity of cream on the keeping qualities. This was done to determine (he test method of making butter for storage. The investigations . have, been carried on. by Messrs L. A. Rogers and 0- E. Gray, and included the making of experimental lots of butter by different methods and in different parts of the country. This butter was kept ir. cold storage, and was examined and scored at certain intervals, the scoring being done by men who had no previous- knowledge of how, when, oi where the butter was made, so that their conclusions were based strictly on the quality of the butter. A repo if

this work ha 3 just been issued as Bulletin 114 of the Bureau of Animal industry.

A 6 a result of the investigations it was found that butter frequently undergoes marked changes, even ..when stored at very low temperatures, and that these changes are more marked as the acidity of the cream from which the butter is made is increased. No bacteria were found in the cream or the butter which could reasonably be expectsd to be the cause of the mowrapid deterioration of the high acid butter. Furthermore, the changes in the high acid butter were not checked by heating the ripened cream, which shows that they were, not brought about by enzymes secreted with or in the cream and carried into the. butter. The results also indicated that acid which developes normally in the cream by the action of certain bacteria, or whicr is added directly to the cream in the form of pure acid, brings about or assists itt bringing about a slow decomposition of one or more of the compounds of which butter is-largely composed. . What is regarded as of special -importance is the • fact- thai butter can be mad* commercially from sweet pasteurised cream without the addition of a starter. Fresh buter made this way has a flavour too mild to suit the average dealer, but it changes J»ns in storage than butter made by the ordinary methods, and can be sold after storage as high-grade butter. At the present time, there are afb least ten • creameries in the country making; butter from sweet pasteurised cream without a starter, and many more with a starter but without ripening. The statement*, in regard 'to butter from unripened pasteurised cream do not hold for butter made from unpasteurised cream churned without ripening. Butter made in this way has poor keeping quality.