TREATMENT OF CREAM PREVIOUS TO THE CHURNING. 233 



Latest Investigations.* Since the above was written 

 (1891) the question of the application of pure cultures in 

 the ripening of the cream has taken a great step forward 

 so that it now may be safely said that the problem is prac- 

 tically solved. Pure cultures that will keep are now in the 

 market; they are put up in a practical manner, and as a 

 rule contain pure distinct cultures of bacteria. Denmark 

 has again taken the lead in this matter, and now furnishes 

 an article which is as easily applied as, e.g., rennet extract. 

 According to what I have been able to ascertain pure cult- 

 ures can be bought in Denmark from not less than three 

 firms Blauenfeldt and Tvede, Copenhagen ; Chr. Hansen, 

 Copenhagen; and Quist of Nonneberg. 



Pure cultures inoculated in a fluid were at first intro- 

 duced in the trade, but it was impractical both to ship 

 and to apply the cultures as put up in vials. Such 

 liquid pure cultures do not, on the whole, seem to be able 

 to keep very well; they may, however, be applied with ad- 

 vantage if they can be used when fresh and are kept under 

 favorable conditions; the shape of the vials in which the 

 cultures are shipped has also been improved of late. The 

 solid pure cultures recently placed on the market are bet- 

 ter, especially if the pure culture cannot be secured fresh. 

 These can stand being kept for months, even half a year, 

 without being appreciably changed in their qualities. 



At the creamery of the Mustiala Dairy Institute, solid 

 normal starter from Danish Butter Color Company, Blau- 

 enfeldt and Tvede, Copenhagen, is at the present being 

 used with great success. In applying it the following di- 

 rections given by the manufacturers are followed : 



* Author's addition to the present translation. 



