milk by the per cent. of fat in cream and multiply the result by 100. Example: How many pounds of cream containing 25 per cent. of fat are produced from 100 pounds of milk containing 5 per cent. of fat? 5 25.2. .2×100=20, number of pounds of cream with 25 per cent. of fat.

26. FINDING AMOUNT OF SKIM-MILK

Rule. To find the amount of skim-milk for 100 pounds of milk when the per cent. of fat in milk and in cream is known, find the amount of cream by Rule 25 and then subtract this from 100. Example: How much skim-milk is produced from 100 pounds of milk containing 4 per cent. of fat when the cream contains 25 per cent of fat? 4÷25.16; .16×100=16; 100— 16=84, number of pounds of skim-milk.

27. FINDING AMOUNT OF BUTTERMILK

Rule.—To find the amount of buttermilk for 100 pounds of milk when the per cent. of fat in milk and in cream is known, multiply the amount of fat in 100 pounds of milk by 1.17 and subtract the result from the amount of cream. Example: How many pounds of buttermilk are produced for 100 pounds of milk containing 4 per cent. of fat, when the cream used contains 25 per cent. of fat? 4x1.17=4.68 (pounds of butter made); 4÷25×100=16 (pounds of 25 per cent. cream); 16—4.68=11.32 (pounds of buttermilk).

28. FINDING SPECIFIC GRAVITY OF
MILK-SOLIDS

Rule. To find the specific gravity of milk-solids, when the specific gravity of the milk and per cent. of milk-solids are known, multiply the specific gravity of the milk by 100, from the result subtract 100 and divide this result by the specific gravity of the milk. Subtract the last result from the per cent. of milk-solids and then divide this result by the per cent. of milksolids. (See p. 139.)

29. FINDING AMOUNT OF ADDED WATER
IN MILK

See page 142.

30. FINDING AMOUNT OF MOISTURE IN BUTTER Rule. To find the approximate amount of moisture in butter, add 3 to the per cent. of fat (obtained by the method described on p. 85) and subtract the sum from 100. In adding 3, allowance is made for I per cent. of casein and 2 per cent. of salt in the butter. The results by this method should in most cases be within 1 or 2 per cent. of the correct figures. Example: How much moisture in butter containing 83.7 per cent. of fat? 83.7+3=86.7; 100-86.7 13.3, the per cent. of moisture.