1C 



DEPARTMENT OF AGRICULTURE. 



RIPENING THE CREAM. 



In order to ripen cream properly, the temperature must be made favourable to 

 the development of the lactic-acid bacteria. This temperature is usually somewhat 

 above 00 Fahr. The object of ripening or souring the cream is to produce flavour 

 and aroma in the butter, to get a more exhaustive churning, and to improve the 

 keeping qualities of the butter. These flavouring substances, so far as known, can 

 only be produced by a process of fermentation. The best flavour in butter is obtained 

 when the cream assumes a clean, pleasant, acid taste during the ripening. For this 

 reason it is essential to have acid-producing germs predominate during the ripening 

 process ; all other germs should be excluded, or at least retarded, if possible. 



Cream ripened at a low temperature (60 to 70 

 Fahr.) does not sour very rapidly; the germs do not 

 multiply at a very rapid rate. The desired degree of 

 acidity is approached very slowly, and in consequence 

 the fermentation may be checked almost at once when 

 desired. The chance of getting overripe cream is thus 

 reduced to a minimum. If the cream is ripened at a 

 high temperature (75 to 80 Fahr.) there is danger 

 of getting overripe cream, which makes a strong- 

 flavoured butter with poor keeping quality. Extreme 

 and rapid changes of temperature should be avoided 

 as much as possible. A good thermometer (Fig. 7) 

 should be used in every well-regulated dairy. The 

 more uniform the temperature can be kept, if suitable 

 for proper ripening, the better the results. 



There are two ways of ripening cream ; the first 

 is to allow it to sour naturally, as a result of the 

 action of the bacteria which are normally present in 

 the cream. By the second method the cream ripens 

 as a result of the action of certain kinds of bacteria 

 which are added in what we know as a " starter," or 

 pure culture. 



A " starter " is milk which has been properly 

 soured, has a pleasant, clean, acid flavour, and is 

 capable of producing a similar flavour in the cream 

 to which it is added. The object of its use is that 

 the bacteria which you know will produce a fine- 

 flavoured butter may take possession of the sweet 

 cream before other and perhaps objectionable germs 

 gain control of it. Buttermilk or sour cream from a 

 previous churning are sometimes used, but their use 

 is not to be recommended, for the reason that, even though the flavour is good, 

 there are always present some undesirable germs which will multiply in each suc- 



Fig. 6. A good type of cooler. 



Fig. 



Floating dairy thermometer. Makes definite knowledge of temperature 

 possible. 



cessive lot of cream or buttermilk used as a starter, so that after a week's time 

 the flavour may actually be bad. When cream is slightly off-flavoured, and a 

 portion of this, or the buttermilk from it, is used as a starter, it will readily be 

 seen that the taint will not only be transmitted, but will increase from day to day. 



