Peas were formerly gathered by hand. Five pods usually form upon each vine, and the lowest is only about 10 inches above the ground. This part of the work was, therefore, very slow and laborious, and requires an amount of help available to but few factories. At present there is only one large factory known to the writer employing hand labor in the picking of the peas. It requires about two thousand pickers to keep a large factory in operation, and adds a cost of about 1.5 to 2 cents to each can. The method in general use is to cut the vines with a mowing machine, or, if any are exceptionally erect, to use the self-rake reaper. If the mowing machine be used, then it must be followed immediately by men with forks to bunch the peas in order to prevent trampling by the horses, and to put them in condition for easy loading. Within the past year or two special attachments have been devised to be connected to the mowing machine for the purpose of bunching and delivering to one side. The cutting is usually done early in the morning, and only such part of the field is cut as can be delivered promptly to the viner. The object is to prevent any heating of the vines or any drying. The vines are loaded upon wagons, like hay, and hauled to the vining machines. GRADING AND VALUATION OF CROP. The basis on which peas are paid for varies greatly at the different factories. Many pay a flat price, so much per bushel or hundred pounds of shelled peas. When this plan is pursued it is advantageous to the factory to insist on the peas being delivered as young as it is possible to use them in order to get the maximum amount of small peas, but it is to the farmer's advantage to delay hauling them in order to get an increase in growth and weight. Such a method is not fair to either factory or producer, neither is it fair to the different producers, one with a first-class load and another with an over-ripe load. A second method is to have a scale of prices for two or three grades of peas. The rating of any given load is made by an expert and is a matter of judgment. The appearance of the vines, the size of the peas, the hardness to the sense of touch when squeezed between the fingers, and sometimes the taste are the factors which guide in the decision. Such a method is manifestly better than a flat rate of so much per bushel, but it is not nearly so accurate as could be desired and is also subject to personal bias. A third method is to pay two or more prices, according to the percentage of peas of a given size. A half-gallon measure of peas is taken out of a given load and poured into a box having a bottom perforated with No. 3 holes. If, as the result of shaking, one-half or more of the peas pass through the sieve and they are fairly soft the second price is paid; if the peas be overripe or hard the lowest price is paid. This method is used by a number of factories, and, although not perfect, is an improvement over the other two. A fourth method is to take a sample from each load during the thrashing and run it through the grader. The sample usually weighs 10 pounds, and the screens in the grader corresponds to those used in the factory. The weights of the five grades are taken separately and the price is established upon the percentage of the different sizes of peas. Some factories modify this procedure slightly by rating Nos. 1 and 2 together and Nos. 4 and 5 together, thus making three grades in size as the basis for payment. The greater the percentage of the smaller sizes of peas, the higher the price paid for a bushel. This method seems the fairest of those now in general use. The fifth method for payment is based upon quality, rather than upon size, as in three of the methods described, in which it is assumed that small size is associated with immaturity and tenderness, an assumption which is not always in accordance with facts. Large peas may be as soft and tender as the small ones, and small peas may be as hard as those that are over-ripe. This method consists in taking a few vines as a sample from each load, shelling the peas and placing them in a cylinder which has a perforated bottom and is suspended in a salt solution. If the peas are young and tender a large percentage will float in a weak brine. If they are older or second grade they will sink in a light solution, but will float in a heavier one. If old, hard or overripe they will sink in the heavier solution. The density of these solutions is varied within narrow limits for the early and late varieties of peas, and is discussed in more detail under grading in the factory. This method is expeditious, and experience has shown that it is as nearly accurate in practice as the fourth method of grading based on size. The ideal grading system should be based on a combination of size and weight. FACTORY OPERATIONS. VINING OR THRASHING. The separation of the peas from the pods and vines is accomplished by a single operation. The viner is an ingenious though simple piece of mechanism, consisting of an outer cylinder having perforations of such size that peas will pass readily through, but which will retain the pods and vines, and an inner cylinder upon which there are paddles or beaters. The outer cylinder is made to revolve slowly in one direction, and the inner one at a high rate of speed in the opposite direction. The vines are fed in at one end of the cylinder and are carried up by the slower-moving outer cylinder until they fall off, and in so doing strike the paddles upon the rapidly revolving inner cylinder. The impact of the paddle causes the pod to break open and the peas to be thrown out. The process is repeated again and again as the vines work from one end of the cylinder to the other. The peas are discharged through the perforations of the outer cylinder and the vines at the opposite end. The work is done thoroughly and the peas are not bruised or crushed by the operation, as might be expected. As a further aid in separating the smaller bits of stems, leaves, etc., the peas fall from the cylinder upon a moving web placed at such an angle that the peas will readily roll down into the receiver, while the flat leaves and other particles which will not roll will be carried off. The vining machines are supplied to the different factories upon a royalty basis, the charge being 3 cents per dozen cans for all shell peas put up at the factory. These machines are large and, as a rule, are set in batteries at the factory instead of being taken to the fields. A few of the very large factories have established vining stations at varying distances from the factory and bring in the shelled peas by wagons, automobiles, or rail. This practice requires rapid handling, as the peas will heat much more quickly after than before being shelled. A large saving in the hauling of vines is effected, and the injury to the peas is probably not greater than would occur in letting the vines wait. These viners were formerly fed by hand, but recently a mechanical feeder has been devised, so that the vines are pitched off the load and the machine completes the work. An automatic weighing device has also been added to take the place of the pea collector and weigher, and conveyors are used to carry all vines to the stack or silos so that the actual hand work is reduced to a minimum. Shelled peas which are hauled to the factory must be kept in thin layers rather than in bulk. The best carrier seems to be a box about 6 inches deep, having a raised wire bottom made like that of a berry box. The layer of peas is only about 4 inches thick and is well ventilated. The boxes or crates, no matter how constructed, must be sterilized with steam and rinsed with scalding water each day or they will become infected with germs which will cause spoilage. WASHING. The first operation through which peas pass after being weighed from the viner is that of washing. This is accomplished in what is known as the squirrel cage, which is a wire cylinder about 3 feet in diameter and 12 feet long. The cylinder is set on a slight incline so that when the peas are admitted at one end they will tend to roll to the other as the cylinder revolves. On the inside is a perforated pipe that sprays a stream of water upon the peas, which insures their being well washed, provided the spray has some force. When the weather is very warm and the peas accumulate more rapidly than they can be passed through the filler, it may be necessary to wash the shelled peas in cold water every few hours in order to prevent fermentation. The washing should be thorough, not only to remove all dirt, but also the mucous substance, thus insuring a clearer liquor. GRADING FOR QUALITY. After the peas pass through the washer, they should be graded according to the degree of maturity or hardness. This is accomplished by passing them through tanks containing salt solutions of different densities. It has been found that the young, tender peas will float in a salt solution somewhat heavier than water, and those more mature will sink, while the very mature peas will sink in a heavy salt solution. Peas, therefore, may be sorted very readily into different grades according to their density by using different strengths of salt water. In practice three grades have been made. The first grade consists of all peas which will float in a solution having a specific gravity of 1.040. The second grade consists of those peas which will sink in a solution of this density but which will float in a solution having a specific gravity of 1.070. The third consists of the peas which will sink in the latter solution. A machine has been devised to remove the peas from the top and bottom of these solutions so that their separation is automatic and continuous. The principle involved in the separation of peas into grades for quality is not new, having long been applied to the selection of seeds. It was tried for grading peas for several years without success, because solutions having the proper density were not obtained and the necessary working apparatus was not available. On May 27, 1894, a patent was granted on a device for grading peas, which has since been improved so as to work very well. The grading of peas for quality is as sharp and clear as that for size. The lightest weight peas are the finest, being even in quality, succulent, and tender. The heaviest peas are the poorest, being uneven in quality, hard, overripe, and of bad color. The middle-weight peas are good, but harder than the first grade, of darker color, and not so uniform. These differences are most apparent before the canning is done, though they are readily distinguishable in the can, and also show on chemical examination. In any load of peas there must be some plants more mature than others, and, as a consequence, some hard peas will be mixed with the tender ones. Every effort is made to cut the peas at nearly the same state of maturity, but no field will ripen perfectly evenly. If the peas be produced by a hundred farmers, the differences will be accentuated. In localities where the peas mature slowly, the differences will be less marked than where they mature rapidly. Under any conditions there will be some differences in quality, and under unfavorable conditions the percentage of poor peas may be very high. Separation for quality is so well effected by the specific gravity grader that it undoubtedly will receive a recognition equal to that given the sizing machine. According to an Indiana factory, in which the quality system of grading has been developed, peas rated good and poor upon the wagon gave the following results after passing through the grader : Had the specific-gravity system not been in use the output of first-class peas would have been much smaller and that of second and third grades correspondingly increased. The trade permits a small percentage of hard and off-size peas in the first grade, but with this system these "off" peas are very few. The characteristics of the different grades will be considered again under the finished product. A chemical examination of peas graded for quality as well as for size results as shown in the following table: Chemical examination of peas graded for size and quality. (Analysis made in the Division of Foods, Bureau of Chemistry.) 22.06 1.36 5.31' 2.21 0.96 10.23 0.987 0.00 1.012 2.44 3.06 The table shows more total solids and higher protein and starch content in the third-grade goods. This might be expected, as the third grade represents the more mature product. If canned peas were purchased for their nutritive properties only, then the third grade would be the preferable one to 1.49 2.604 buy, but they are usually selected for their delicacy and flavor, which are found in the highest degree in the youngest and tenderest peas, or the first grade. GRADING FOR SIZE. The grading for size is a very simple matter. The peas are passed over sieves, or into a revolving cylinder having four sections with perforations of different sizes. The perforations in the first sieve or section measure nine thirty-seconds of an inch in diameter. The peas which pass through this size opening are known as No. 1, or "petits pois." The next size of perforation is ten thirty-seconds of an inch in diameter, and the peas passing through are known as No. 2 "extra sifted," or "extra fine." The third size of perofration is eleven thirty-seconds of an inch, and the peas which pass through are known as No. 3 "sifted or fins." The last size is twelve thirty-seconds of an inch, and the peas which pass through are known as No. 4, or "early June" peas. The peas which are too large to pass through this sieve go over the end and are known as No. 5, or "marrowfats." Some packers add one more sieve for late peas, with perforations thirteen thirty-seconds of an inch in diameter for the No. 5, and those which pass over this sieve are called No. 6, or "telephone peas." The sizes of these perforations are standard and in general use. Some packers have attempted to make sizes of their own by reaming out the holes, while others do not use all four sieves, but group two sizes together; and some peas are ungraded. These sizes are so nearly standard for all pea packing that they should be adhered to in the labeling. The term "early June" peas as now used applies to a certain size and not to the season at which the peas are picked, and the size larger, or "marrow fat," should not be labeled "early June." "Extra early June" or "May pickings" is not a proper designation for sifted peas. It is evident that the standard terms used to designated size should be employed in labeling if the proper meaning is to be conveyed to the purchaser. Commercially, almost any size of pea may be found to be selling as "early June" in the cheaper grades. The more expensive peas are usually sold true to name, though it is not unusual to get smaller peas in the high grades than is indicated upon the label. The terms "early June," "May pickings," "extra early June," and others of that character could be advantageously supplanted by names more distinctive of size, as the present terms conflict with the requirements of the food and drugs act as to labeling, unless the product be actually packed at the time indicated. The percentage of peas which go into the different sizes will vary considerably with the time of harvesting, the variety, and the season. One of the large factories furnishes the following figures upon the crops for 1906 and 1907: Percentage of different sizes in the crops for two years. It is not known how these figures will compare with the grading for the entire country, as this is a matter which canners do not make public. |