1910.] The Use of Starters in Dairying. 719 



culture for the next day, it should be occasionally stirred 

 during the evening, but not on the following morning. The 

 preparation of home-made starters exerts a purifying influence 

 on the bacteria content of the starter, and results in the 

 elimination of bacteria which are unnecessary, if not harmful, 

 to the production of a first-class article. 



The characteristics of the bacteria in a starter should 

 resemble those found in ripened cream or in good cheeses, 

 and they should by no means produce gas. The culture 

 should have a clean, sharp, acid flavour, and when added to 

 milk or cream be capable of eclipsing to a large extent the 

 development of obnoxious bacteria. The organisms should 

 neither liquefy gelatine nor produce spores, and when 

 examined under the microscope should occur in pairs or 

 figure eight, as short bacteria with rounded ends. 



Butter-making. — The proper ripening or souring of milk 

 is of great importance in the manufacture of the best quality 

 of butter. Fresh cream already contains about 'io to '12 per 

 cent, of lactic acid, but this acidity has to be increased up to 

 about "6 per cent, before cream is sufficiently ripe for churning 

 into butter. In some dairies, however, "45 per cent, of lactic 

 acid is thought sufficient. The amount of acid necessary in 

 ripened cream is by no means constant, as this varies with 

 the time of year, breed of cow, etc. Generally speaking, 

 the acidity in cream should be developed to a greater extent 

 in spring or autumn than in summer. Milk or cream from 

 Ayrshire cows needs more acidity than that from Jerseys; 

 this is due to the ripened cream being more tenacious in 

 the case of the Ayrshire product, thus hindering the releasing 

 and running together of the fat globules, which are entangled 

 in it during churning. 



Little doubt now exists with regard to the advisability of 

 ripening cream, as it gives more flavour to the butter, makes 

 it easier to churn, and also gives an increased yield of butter, 

 often as much as 8 per cent. more. 



The natural ripening of cream is not altogether satisfactory, 

 because in this case the cream is left exposed to the 

 atmosphere of the dairy, and the length of time for ripening 

 varies with the temperature of the dairy, as well as with the 

 addition of fresh cream from day to day. The higher the 



