CURING RENNETS.
It is usually understood that rennets are calves' stomachs salted and dried, or otherwise prepared; but it is not so certain that all the rennets in market are of this kind. The stomachs of the young of all milk-eating animals may be used for curding milk. We are not so sure but that among "Bavarian" rennets we get the stomachs of the young of every animal known under the sun. They are of all sizes and all degrees of strength, but are generally liked by those who use them. They are cured by tying the two ends, and blowing the rennets up, like bladders. A better way, we think, is to rub them well with pure dairy salt, stretch them on a hoop or crotched stick, and hang them in a cool dry place. Some simply fill them with salt, tie them, and hang them up to dry. A great objection to this is, that the salt is likely to draw moisture from the atmosphere, and in wet weather the rennets are liable to drip and thus lose strength. Salting rennets down in a barrel, as we do meat, is considered objectionable—for what reason, we know not. The writer had excellent "luck," one season, with rennets preserved in this way. In whatever way preserved, rennets should, by all means, be kept cool. Heat is found to be very injurious, while cold—even freezing and thawing—appears advantageous. Possibly because the freezing and thawing loosen the fiber and set the rennet spores free.
AGE AN ADVANTAGE.
No rennets less than a year old should be used, if it can possibly be avoided. The old rennets, other things being equal, are stronger and make a firmer curd than new ones. Any one who has experimented with both will always aim to have a supply of good old rennets on hand.
SAVING RENNETS.
In saving rennets, great care should be taken to have them right. The fourth stomach of the calf is what is saved. Cut it from the adjoining stomach, at the point of junction, and do not leave a piece of intestine on the other end, but cut close to the opening of the rennet. Remove straws and dirt of all kinds carefully, but be sure to not rub off the delicate lining of the stomach, which is the digestive or coagulative part and very much inclined to adhere to your hands, especially if they are dry. Do not try to rinse off anything more than the loose dirt, and that without rubbing, for you cannot rub without waste. What is better, avoid having dirt or any thing else in the stomach to remove. This you can do by letting the calf go sixteen or eighteen hours without eating, and placed where it can get hold of nothing to swallow before killing. Say, feed it at night and slay it the next day about noon. The stomach will then be empty and clean and well stored with pepsin for the digestion of the next meal. This secretion, is just what you want. The rennet is best when the calf is six or eight days old. But, in any case, digestion should be well established before killing. If the calf should go too long without food—as is often the case with veal calves—the stomach will get inflamed. This is objectionable.
SELECTING RENNETS.
In selecting rennets to soak, all discolored and bad smelling ones should be scrupulously rejected. But rubbing rennets is a disagreeable and disgusting business, and it is somewhat difficult to keep your rennet of uniform strength. Therefore, if good rennet extract can be bought at a reasonable price, we would recommend its use. It ought to be made better and cheaper in a wholesale way than in little batches at each factory. To guard against imposition, one should buy only of known reputable dealers. Preparing your own rennet is much like doing your own shoe making. It doesn't pay, if you have got anything else remunerative to do.
WHOLESALE PREPARATION.
If one must prepare his own rennet, the better way is to do it in a lump before the cheese-making season begins. Get a strong barrel and a pounder—such as used by washerwomen; also a wringer. Take old rennets and cut them into strips. Make a weak brine of pure water, by using one pound of salt to twenty pounds of water, and in this, soak, pound and wring your rennets. Hang them up and freeze them; then soak, pound and wring them again; and so on as long as you can get any strength. When done, carefully settle, skim, and strain your liquid. Put it in a clean barrel or stone jars, put in all the salt that it will dissolve, so that a little will settle on the bottom, then stop or cover tight; put in a cool place and take from it as wanted for use. There is nothing better than saturated brine for keeping animal products. Be sure, however, that you use only the purest dairy salt in preparing brine. Some say that only stone jars should be used for keeping rennet. We have used an ash tub for the amount prepared weekly. To keep the wood from tainting, we invariably, every time we dipped out rennet and exposed new surface, rubbed it with salt.