+67. Examining starter.+--This starter should be examined carefully as to physical properties, odor and taste. The coagulation should be smooth, free from whey and gassy pockets or bubbles. Sometimes the first few inoculations from a new culture will show signs of gas, but, usually, this will quickly disappear, and not injure the starter. It should have a clean sour cream odor and clean, mild, acid flavor. After breaking up it should be thick and creamy, entirely free from lumps. This starter may have an objectionable flavor, due to the media in which the organisms were growing when shipped. In such cases it is necessary to carry the starter one or two propagations to overcome the flavor, to enliven the micro-organisms and to secure the quantity desired. +68. Second day's propagation.+--For the second day, the milk for the starter is selected as on the first day. It is pasteurized, and this time cooled to 70° F. The milk is cooled a trifle colder the second day than the first, because the organisms have become more active and hence do not require as high a temperature to grow. Instead of inoculating with powder, as was done the first day, the mother starter prepared the first day is used. This requires only a very small amount, perhaps a tablespoonful to a quart bottle. It should be thoroughly mixed with the milk. This starter may have the flavor of the media used in the laboratory culture, therefore may need to be carried one or two days more to eliminate it. After the flavor has become normal, the mother starter is ready for commercial use. [Illustration: FIG. 6.--An improved starter-can.] +69. Preparation of larger amount of starter.+--The first thing to determine is the quantity of starter required. As much milk should be carefully chosen as the amount of starter desired. This milk should then be pasteurized. An improved starter-can (Fig. 6) may be used in the pasteurization of the milk and the making of starter, or a milk-can (Fig. 7) placed in a tub of water in which there is a steam pipe. The former requires mechanical power to operate the agitator, but the latter can be used where mechanical power is not available. In the latter the milk and starter are stirred by hand. This is the kind of apparatus more often found in cheese factories. [Illustration: FIG. 7.--A simple device for the preparation of starter.] If possible, this milk should be pasteurized to 180° F. for thirty minutes; this kills most of the bacteria and spores. The milk should be cooled to 60°-65° F., the temperature of incubation. This temperature may be varied with conditions, so that the starter will be ready for use at the desired time. The higher the temperature, the less time is required to ripen the starter. +70. Amount of mother starter to use.+--The mother starter prepared the day before is now used to inoculate the starter milk. The amount to use will depend on: 1. Temperature of milk when mother starter is added;