Equipment

A supply of clean wooden kegs or stone crocks is the first requisite. For home use the smaller sizes are preferable as a rule, because the contents will then be used up more quickly and there will be less chance of molding from standing too long after the kegs or crocks are opened. Wooden kegs holding 5 or 10 gallons are a convenient size. New kegs are preferable, but old ones, such as beer or cider kegs, may be used if they are thoroughly washed and steamed to remove any undesirable odor or flavor which might be imparted to the foods packed in them. Wooden vessels of yellow or pitch pine are undesirable, since they are apt to give a disagreeable taste to the foods. Stone crocks or jars holding from 1 to 5 gallons are convenient. Stoneware is less likely to absorb flavors than wood, and stone jars may be obtained in smaller sizes than wooden kegs. Wide-mouthed bottles or glass jars, which are not suitable for canning, may also be used for salting or fermenting small quantities of foods.

* Round, L. A., and Lang, H. L. Preservation of vegetables by fermentation and salting. Farmers' Bull. 881, U. S. Dept. of Agr.

A supply of ordinary fine salt, which can be purchased in bulk for about 2 cents a pound, is most satisfactory for general use. Table salt will do very well, but is rather expensive if large quantities of vegetables are to be preserved. The rather coarse salt (known in the trade as "ground alum salt"), which is used in freezing ice cream, can be used. Rock salt should not be used because it is too coarse and is likely to contain impurities.

Clean white cloth (cheese-cloth or muslin) is necessary for covering the material after it is packed into the container. It will be convenient to cut this into circular pieces about 6 inches larger in diameter than the stone crock or keg. Two or three thicknesses of cheese-cloth or one thickness of muslin or heavier cloth should be spread over the top of the vegetables.

Round pieces of board about 1 inch or more in thickness will be needed to put on top of the cheese-cloth. The boards should be a little smaller in diameter than the inside of the crock or the head of the keg or tub, so that they will slip in and out easily. The pieces may be sawed out at a lumber mill, or may be made at home by fastening together several boards with cleats and rounding them with a small saw and a carpenter's shave. Almost any wood may be used except yellow or pitch pine, which is likely to impart an undesirable flavor to the vegetables. For small containers, if preferred, heavy plates of suitable size can be used instead of boards.

One or more clean bricks or some clean stones may be used as weights to hold down the mass in the keg or crock.

Paraffin is needed to pour over the liquid in the containers (after fermentation has ceased) to prevent mold.

A pair of kitchen scales or steelyards and a quart or gallon liquid measure complete the necessary equipment.

Fermentation With Dry Salting

As has already been stated, fermentation with dry salting consists in packing the material with a small amount of salt. No water is added, for the salt extracts the water from the vegetables and forms the brine. The method, in general, is as follows:

Wash the vegetables, drain off the surplus water, and weigh them. For each 100 pounds of the vegetables weigh out 3 pounds of salt; for smaller quantities use the same proportion (3 per cent by weight) of salt. Cover the bottom of the keg, crock, or other container with a layer of the vegetables about 1 inch thick and sprinkle over this a little of the salt. Do not add too much of the salt to the first layers packed, but try to distribute it equally among the different layers so that the quantity which has been weighed out will be sufficient for the given quantity of vegetables packed. If a little of the salt is left over, it can be added to the top layer, but if more has to be added than has been weighed out, the finished product will taste too salty. Continue adding layers of the material sprinkled with salt until the container is about three-fourths full. Sprinkle the last of the salt on the top layer and spread over it one or two thicknesses of cheese-cloth, tucking them down at the sides. On the cloth place one of the round pieces of board or a plate, and on this put a clean stone or one or two clean bricks. The size of the weight depends on the quantity of material being preserved. For a 5-gallon keg a weight of 10 pounds will be sufficient, but if a larger barrel is used, a heavier weight will be needed. The weight added should be sufficient to extract the juices to form a brine, which will cover the top in about twenty-four hours and sometimes it may be necessary to add more stones after the material has stood a while, if a brine does not form.

After it is packed, allow the container to stand in a moderately warm room to ferment. The salt and pressure of the weight soon extract water from the vegetables and form a brine which soon covers the whole mass. The stone and board serve to keep the vegetables beneath the surface of the liquid. If the weight is not sufficient for this purpose, a larger stone or more bricks should be added. As the fermentation goes on, bubbles arise to the surface of the liquid. The rate of fermentation depends principally on the temperature. In warm weather it requires only eight to ten days; in cool weather two to four weeks may be necessary. When bubbling stops, fermentation is complete. A good way to determine this is to tap the receptacle gently; if no bubbles arise, fermentation is finished.

The containers should then be placed in a cellar or other cool storeroom and the surface of the liquid treated to prevent the development of a scum of mold. If this is not done, a thin film will appear on the surface of the brine soon after fermentation ceases, which will spread rapidly and develop into a heavy folded membrane. This scum is a growth of micro-organisms which feed upon the acid formed by fermentation. If allowed to grow undisturbed, all the acid will eventually be destroyed and the fermented material will spoil. This scum must be prevented from forming if the product is to be kept for a considerable time. Exclusion of air from the surface of the brine will entirely prevent its formation. There are three feasible methods of accomplishing this.