Use nothing but stone jars for keeping rennet. If a mess of rennet worth, perhaps, a dollar should get slightly tainted, throw it away rather than impregnate it through $200 worth of cheese and cause serious illness among numerous human beings. Use only annottoine cut directly from the seed by the chemical action of potash. The imputation that urine is used in the paste preparation should make every manufacturer shun it with loathing until the vile stigma is disproved. Be at least five minutes in stirring the rennet into milk. Stir it with great gentleness, so that the butter globules will not be displaced. Curd should stand not less than forty or more than sixty minutes after the application of rennet before cutting, the variation in time to be governed by season, condition of milk and desired keeping qualities. Curd is fit to cut up when it will split clean before the finger but is not so brittle as to break before the advancing knife. Cut first with the horizontal knife lengthways, then crossway, then lengthways with the perpendicular blade. If milk is very ripe, and a quick scald is necessary, cut once more crossway with the perpendicular blade. Never slash curd in cutting, as it starts milky whey and lowers your yield. After cutting curd if milk is in normal condition, it is, perhaps, better to agitate the curd gently for a few moments before heat is applied. If milk has already taken on acid, apply heat immediately after cutting. In agitating curd use the hands for the first fifteen minutes, then manipulate it with a rake. Stir only enough to keep it separated and prevent it from scorching on the hot bottom of the vat. Remember that cooking curd thoroughly is, without doubt, the most important part of the whole programme of cheese making. Do not place sole reliance on thermometer figures—let your judgment rule supreme above that. See that every day’s curd—the product of milk in all stages of maturity—does not part with the whey until it is cooked to a state of contractibility in which the cubes will separate by expansion after pressure by squeezing in the hand. No maker considers his bread free from rawness until it has received a certain amount of heat in the oven, and no cheese maker can expect to get a mellow, firm cheese unless he cooks his curd as above described. By using the smallest amount of heat possible to cook curd within a reasonable time, a finer quality of cheese is secured and a better yield. Hold curd in the whey until it will string fine threads, one-fourth of an inch in length, on the hot iron. Aim to have the whey well drained out of the curd before it is ground. Do not grind curd when it is too hot. If necessary, cut into small blocks or strips and scatter over the bottom of the vat, to cool to a temperature to about 85° Fahrenheit before grinding.