At this time the hulls will be perfectly sound and not objectionable, in so far as staining the hands is concerned. But if the hulls be broken open the juice which they emit will leave a lasting stain on the hands or garments. But the hulls need not be broken to any great extent.
Hulling
The ordinary corn sheller on the farm is undoubtedly the most practicable instrument for removing the hulls, generally available at this time. If the hulls are still green enough to be firm, the nuts may be placed in the machine by hand. Otherwise, some arrangement may be worked out by which the nuts may automatically be fed into the machine. After hulling by this method the nuts should be put into a tub or tank of water and thoroughly washed with a broom or stiff brush. When the nuts are hulled promptly and well washed it will be discovered that the natural color of walnuts is light or whitish and not black. The dark color is wholly due to stain from the green hulls. This stain, by the way, loses its effectiveness as soon as the hulls turn dark. Stains from nut hulls which have lost all trace of green color, so that the hulls are black, are readily washed from the hands.
After the nuts have come from the sheller they may be handled by shovels or by forks with tines close together. They should then be cured for a few days. For this purpose they should never be placed in piles or deep layers. Preferably they should be spread out in trays with bottoms of wire mesh or narrow cleats so as to be open. These should be put where there will be a free circulation of air all about. Where trays are not available the nuts may be spread on a barn floor and the doors left open during the day. If the weather is bright they may be spread on boards laid on the ground directly in the sun, although it is probable that they should be given partial shade during extremely hot days.
Various methods of hulling other than by the corn sheller are in use. Some involve merely stepping on the nuts with a forward movement of the foot, just as the hulls are softening. This is not particularly satisfactory as the nuts must still be picked out of the mashed hulls by hand. Besides leaving a very persistent stain on the hands this method is unsatisfactory for two reasons; it is not at all rapid and very far from perfect in the degree to which it removes the hulls.
Other methods involve the use of automobile wheels. Sometimes machines are driven over the nuts as they are thinly spread on the ground. Again a wheel is jacked up and set in motion in a tub of water in which the nuts have been placed. Both methods have their advocates. The writer has had experience with the former only, yet he can conceive of little to commend either method.
Still another method is that of pounding off the hulls by hand. Of all common methods this has the fewest conceivable advantages. It is slow, thoroughly inefficient, and extremely objectionable from the standpoint of the stain.
What is perhaps far the most satisfactory method of any yet used for removing the hulls, from every standpoint except that of expense, is one evolved by the Department of Agriculture in 1926. It consists merely of running the nuts through large-sized vegetable paring machines. These machines consist of metal containers, circular in form and having a capacity of approximately 1-1/2 bushels. The inner walls are lined with hard abrasive surfaces. A bushel of nuts is placed inside, the lid closed, a stream of water turned into the container, and the machine set in operation. By means of gears attached to the bottom of the container which is separate from the walls, plated and perforated, the bottom spins around several hundred times per minute. The nuts are made to beat violently against the rough walls with the result that, in from 2-1/2 to 5 minutes, depending upon the firmness of the hulls, the nuts are ready to be taken out. They are then perfectly hulled, thoroughly washed and light or whitish in color.
With a few days of drying, the nuts should be ready for cracking.