With the thermometer in the oil bath registering between 140° and 145° C. (or between 284° and 293° F.), the flask is placed in the cup of the oil bath and the flat disk-shaped cover is adjusted over the apparatus. The flask should remain in the bath for fifty minutes, the temperature being kept between 140° and 145° C. all the time. The flask is then removed, covered and allowed to cool to room temperature in a dry place. It is then weighed, and the quotient obtained by dividing the loss in weight by the original weight, multiplied by 100, gives the percentage of water in the cheese. The following shows the method of computation: Problem: Five grams of cheese was heated until the water contained in it was evaporated. The remaining substance weighed 3.15 grams. What percentage of water did the cheese contain? Answer: 5.00 - 3.15 = 1.85 1.85 ÷ 5 = 0.37 0.37 × 100 = 37 (percentage of water in cheese) A butter-moisture scales with an extra 5-gram weight may be used for weighing out the 5 grams of cheese. If the scales indicates the amount of moisture in 10 grams of butter by percentage graduations on its beam or by percentage weights, then it will be necessary to multiply by 2 the percentage indicated by such scales or percentage weights when only 5 grams of cheese is used. The moisture may be determined by weighing out a small sample of cheese and drying it in an oven and calling the loss moisture. Many such ovens have been devised. New York and Wisconsin have laws limiting the amount of water which may be incorporated in Cheddar cheese. New York places the limit at 39 per cent and Wisconsin at 40 per cent. If the moisture-content is above this, the cheese must be branded adulterated. CHAPTER XX _MARKETING_ Marketing is related to cheese in two ways: First, the purchase of the raw material, the milk; and secondly the sale of the finished product, the cheese. +321. Buying milk.+--The method of paying for the milk differs in the various cheese sections and factories. At some factories a stated price is paid for the milk or the fat. This is usually in terms of 100 pounds of milk or for each pound of fat. This is the practice with concerns possessing large capital. Other factories make the milk into cheese and after each sale, the expenses necessary for operating the factory are deducted and the remainder of the money divided among the patrons. This money is divided either on the basis of the number of pounds of milk or of fat delivered. The question arises as to which is the better method to buy milk for cheese-making, or the fairest way to divide the money received from a sale of cheese.