880 EXPERIMENT STATION RECOED. 



volume of tlie whey contained less bacteria than the milk before curdling, 

 approximately 77 per cent of the bacteria being retained in the curd. These 

 tests were repeated under cheese-room conditions with similar results. 



Whey was found to increase in acidity much more rapidly in contact with 

 the curd than when removed as soon as the curd was cut. In one sample the 

 whey in contact with curd was found to be 0.23 per cent more acid at the end 

 of 10 hours than whey removed when curd was cut. With deep beakers filled 

 with milk, the milk curdled with rennet, the curd cut and allowed to settle, and 

 the beakers so kept as to allow no convection currents it was found that the 

 acidity of bottom layers of whey increased much faster than that of the upper 

 layers, the difference being in some cases 0.4 per cent. 



In a cheese made from milk containing but few acid-producing bacteria the 

 ripening was so delayed that at the end of 3 months the cheese showed spongy 

 texture and scarcely any cheese flavor. In an experiment to show the euzymie 

 action of lactic bacteria by the difference in rate of increase in acidity between 

 raw and heated milk preserved with 3 per cent toluol, the daily increase in 

 acidity of the raw milk was found to vary from 0.0012 to 0.0027 per cent and of 

 the heated milk from 0.0005 to 0.0017 per cent. Since results of inoculation of 

 sterile milk have shown that no growth could have taken place after addition 

 of toluol any increase in acidity of the heated milk must have been due to the 

 enzyms set free by the disintegrating cells that act on the milk sugar during 

 the ripening of cheese. Some cultures of B. lactis acidi produced inactive acid, 

 some dextro-acid, and some mixtures of the two. One culture from another 

 source produced pure levo-acid. 



In studying the percentage of acidity produced by lactic bacilli in milk to 

 which peptone had been added, it was shown that the cessation of their growth 

 in milk when a certain percentage of acidity is reached is not brought about 

 by the antiseptic action of the acid, but by a lack of suitable nitrogenous food. 



The development of B. lactis acidi was followed by the growth of the B. bul- 

 garicMs group. They reach numbers comiiarable with those of the first group, 

 reaching their maximum numbers within the first month of the ripening. Since 

 they developed after the fermentation of the sugar, they must have some other 

 source of carbon and of energy than milk sugar. Coccus, chromogenic, and 

 liquefying types were found and other tests were made which confirmed the 

 work of previous investigators. 



A new use for whey {Alolk. Ztg. Bei-Un, 22 {1912), No. 35, pp. .',09, /flO).— 

 A note concerning a new beverage that can be made from whey, and which is 

 called whey lemonade. The method of making is not described. 



Tatte, the original preserved curd of the North, and other ferm.ented 

 milks; their significance for the nutrition of man, O. J. Olsen-Sopp {CentU. 

 Bakt. [etc.], 2. Aht., 33 {1912), No. 1-6, pp. 1-5J,, pi. 1; abs. in Intcrnat. Inst. 

 Agr. [Rome], Bui. Bur. Agr. Intel, and Plant Diseases, 3 {1912), No. 6, pp. 

 lJt33-lJ,35). — Tiitte is prepared from milk while still warm from the cow, 

 by adding some of the old curd which has been dried on straw or linen cloths. 

 The organisms present depend somewhat on the age of the preparation, but 

 ^freptoJjOciUiis tiitte, Lactobacillus tatte, and Saccharomyces tdtte wei-e always 

 found, and quite frequently species of Monilia, Torula, and Lactococcus. 

 O'idium lactis was common when the preparation was of poor quality. 



"Cellar milk" is another form of fermented milk made in Sweden and Nor- 

 way, and used by the inhabitants of the valleys when the cattle are kept in 

 the mountains during the summer. It is prepared from fresh milk by adding 

 water, boiling, and placing it in the cellar in large wooden vessels preAiously 

 scalded with a juniper decoction and then rubbed with tiitte. The vessels are 

 covered with muslin and the milk after the first week is well mixed every 



