CHEESE 



91 



bacteria to multiply in the milk until a Rennet Test * or 

 Acid Test ** shows that the desired degree of acidity has 

 been reached. The starter may be sour whey or prefer- 



I 



A measuring 

 glass and an ac- 

 curate thermome- 

 ter are indispen- 

 sable 



The Marschall rennet test 



ably prepared from sweet skim milk or whole milk 

 with a commercial lactic acid culture as described in 

 Chapter I under Ferments and Buttermilk. From 1% to 



* The Marschall Rennet Test consists of a graduated cup (a) with 

 a fine hole for an outlet in the bottom. One cubic centimeter of a stand- 

 ard rennet extract is diluted with water in the glass bottle (c). The cup 

 is filled with milk and placed on the corner of the cheese vat, the milk 

 being allowed to run through the fine hole in the bottom of the cup. 

 The moment the surface of the milk reaches the upper mark of the 

 graduation in the cup the diluted rennet extract is added and quickly 

 stirred into the milk with the spattle (d). 



When the milk begins to curdle it stops running out. The sweeter 

 the milk is the more will run out before coagulation stops it and the 

 mark on the scale at which it stops indicates the degree of acidity or 

 ripening. The point is to have the milk alike every day and if, for in- 

 stance, the cheesemaker has found that his cheese is best if he adds the 

 rennet to the milk in the vat when the test shows 23^, he wants to ripen 

 the milk to that degree every day. So, if the test shows 3 or 4, it in- 

 dicates that the milk is not sufficiently ripened and it should be allowed 

 to stand warm for a longer time before it is set with rennet. 



** The Acidometer for making an Acid Test is described in Chapter I. 



