Most tomatoes are delivered to the factory with the stems on, but I know of one plant where they are all received stemless, and the quality of the pulp made from them simply cannot be beat. There surely must be an undesirable taste imparted by all these green stems in the cooking process. Of course, where the cold pulping process is used, that is, the tomatoes pulped cold directly after sorting and washing, these stems are eliminated before any cooking is done. In the hot pulping process, however, and when the tomatoes are put in a crusher instead of a pulp machine, the stems are cooked along with the rest of the pulp. The operator of the plant referred to above pays a bonus of a dollar a ton to his contractors for having the tomatoes delivered stemless, and he believes he gets that dollar back and more, too, in the price he gets for his product, which is very fancy.
CHAPTER II
WASHING AND SORTING
Washing and Sorting Equipment
A great many outfits for washing and sorting tomatoes have been placed on the market, some of which have many good points, and others are very inadequate. The type of washer best adapted to one plant may not be the best for another one. If tomatoes are grown on clay ground a friction washer is necessary, while for fruits grown on sandy soil it is very infrequent that much friction is needed to properly clean the tomatoes.
As to sorting belts, as a rule one type will serve as well in one place as in another. A majority of the sorting belts used are subject to many criticisms; some are too narrow, some too short, some travel at a speed of 100 feet or more per minute, while others move as slowly as 10 feet per minute. The latter speed is much better than the former, although both are extremes, 25 feet per minute being about right.
Rotary Washer
For tomatoes grown on clay ground the cylindrical rotary washer or squirrel cage type made of 1–inch mesh heavy wire is very satisfactory. When tomatoes come to the plant caked with clay, as they are after a hard rain followed by strong sunshine, a friction washer of this type is about the only thing that will clean them. This type of washer also does excellent work on late tomatoes, and this applies to all localities. A large percentage of late tomatoes become deeply cracked at the stem end, and although these cracks, or fissures, usually appear to be healed over, an examination will generally reveal the presence of mold in them, and in many cases large tufts of mold like cotton completely filling them. By merely passing such tomatoes through a water bath, even though the water is thoroughly agitated by means of many inlets of compressed air, this imbedded mold will be scarcely affected. A rotary, heavy wire, reel washer, inclined at an angle of about 1 foot in 8, and rotating slowly, with a heavy, sharp spray of water striking the rolling tomatoes from the time they are dumped in until they roll out, will take out a very large proportion of this mold, besides cleaning the entire surface of the tomato thoroughly.
The washer should deliver about two bushels of tomatoes per minute to the sorting belt. As the wire cylinder revolves, the tomatoes are carried half way up the side and are then thrown back again, being carried slowly and steadily toward the outlet. A 1½-inch pipe at the top of the cylinder, and running from end to end, with small holes bored at intervals of an inch, should direct a sharp, cutting shower of water on the tomatoes as they revolve and rub each other. A fine, sharp spray will accomplish more than a less forceful but larger stream of water coming from a larger opening. The dirt, mold, etc. is washed through the wire mesh into a drip pan, and thence to the sewer.
Some of the rotary washers used are of solid metal, and others constructed of wooden slats have been used. Both of these should be avoided, as the solid metal produces a sliding, instead of a rolling action, and the wooden slats mold quickly and become slimy. Also, some of the washers are slightly too narrow, and the tomatoes are so crowded while they are rotating that many of them do not come in contact with the wire, but merely roll on top of other tomatoes. Other washers are considerably wider than necessary. If the tomatoes are to be fed to the belt at the rate of 2 bushels per minute, a reel (squirrel cage) washer 2 to 2½ feet in diameter, and about 8 feet long, having an inclination of about 1 foot in 8, and revolving at about 20 revolutions per minute, will usually give satisfactory results. These are the figures recommended by Mr. Howard of the Bureau of Chemistry, who has made a very extensive study of the efficiency of rotary washers.
By having the tomatoes thoroughly clean, with no mud and scarcely any mold adhering to the surface when they drop on the sorting belt, the amount of sorting required is not only greatly lessened, but the spots of black rot and other forms of decay show up prominently on the surface.