THE MANUFACTURE OF TOMATO PRODUCTS TEXT

The Manufacture of Tomato Products _INCLUDING_ Whole Tomato Pulp or Puree, Tomato Catsup, Chili Sauce, Tomato Soup, Trimming Pulp _BY_ W. G. HIER _Technologist in the Canning and Preserving of Tomato Products_ Formerly Chief Chemist and District Factory Supervisor of The T. A. Suider Preserve Co. of Chicago [Illustration] Published by W. G. HIER 2324 South Columbine Street Denver, Colorado COPYRIGHT 1919 BY W. G HIER DENVER THE BROCK-HAFFNER PRESS CO., PRINTERS 1919 Preface The past ten years have seen revolutionary changes made in the tomato product manufacturing business. Old methods of making tomato pulp, catsup, chili sauce, etc. have been discarded, and the modern plant presents a very striking contrast to the plant of former days. In this book I have tried to present all the methods used which have merit, and to bring forth the advantages and disadvantages of each so that the packer can weigh them and decide which is best to use under the conditions which obtain at his plant. In some cases one method is universally applicable and has advantages which stamp it as superior, but more often varying conditions of manufacture in different localities make it impossible to recommend any one method for everyone. In writing the text I have had to rely almost entirely on the experience gained during the seven years in which I have been engaged in the manufacture of these products, as there are no books on the subject, and no sources of reference except the bulletins prepared by Mr. B. J. Howard and Mr. C. H. Stephenson of the Bureau of Chemistry, U. S. Department of Agriculture, on the sorting and washing of tomatoes, the handling of tomato trimmings, and the effect of proper and improper sorting and washing on the content of micro-organisms as determined by microscopical examination. I wish to thank Mr. B. J. Howard of the Bureau of Chemistry for the valuable suggestions and information he gave me with reference to portions of the text of Chapter II and Chapter VII, and also to thank the Bureau of Chemistry for permission to use many of their photomicrographs and photographs. W. G. HIER. April 22, 1919. PART I The Manufacture of Whole Tomato Pulp or Puree Table of Contents PART I THE MANUFACTURE OF WHOLE TOMATO PULP OR PUREE PAGE CHAPTER I. OBTAINING GOOD TOMATO STOCK 1 Value of good tomato stock—plant raising—use of fertilizer—methods in east and west—shipping tomatoes—tomato crates—degrees of ripeness for shipping—careful handling at factory—varieties—storing tomatoes—stemless tomatoes. CHAPTER II. WASHING AND SORTING 8 Washing and sorting equipment—rotary washer—water bath with compressed air—importance of agitation—plain sorting belt—number of sorters—tomato turning device—divided sorting belt—sorting—forms of decay—cleanliness of equipment—molds, yeasts and spores, and bacteria. CHAPTER III. PRINCIPAL METHODS IN USE FOR PULPING 20 Cold pulping—care of cyclone—hot pulping—advantages claimed for hot pulping—objections to hot process—crushing—conveying to kettle—value of pumice. CHAPTER IV. CONDENSING THE STRAINED OR CRUSHED TOMATOES 26 Vacuum pan—types of open kettles—steam pressure—copper jacketed kettles—tinning kettles—advantages of various types of kettles—glass-lined tank—cypress tank—cleaning kettles—coil leaks—starting the cooking—methods of gauging finishing point—cooking to gauge on kettle—cooking a definite length of time—determining specific gravity by weight—objections to weighing method—testing with hydrometer—method of using hydrometer—finishing the cook. CHAPTER V. CONVEYING THE CONDENSED, STRAINED, OR CRUSHED TOMATOES TO THE FINISHING MACHINE, AND FINISHING SAME 38 Conveying to finisher—receiving tanks—finishing—screen metal for finisher—effect of finishing on mold count—finishing before cooking. CHAPTER VI. FILLING THE FINISHED PULP AND STORING THE CANNED PRODUCT 41 Filling devices for five gallons—square can and round can—testing for leaks—washing and steaming—filling and capping—handling filled cans—advantages of separating batches—how to stack—processing—life of cans—washing and drying cans—protection from dust—testing used cans—packing No. 10’s and No. 1’s—packing barrel pulp—metal drums—a method of preserving pulp in barrels. CHAPTER VII. THE MICRO-ORGANISMS OF TOMATO PRODUCTS; THE ATTITUDE OF THE PURE FOOD AUTHORITIES TOWARD THEM; AND THE INTERPRETATION OF ANALYSES 51 Micro-organisms; what they are—molds—bacteria—yeasts—spores—how germs retard their own growth—rapidity of growth—the government attitude on micro-organisms—government regulations—state food officials—checking up daily runs—how to interpret analyses. PART II THE MANUFACTURE OF TOMATO CATSUP, CHILI SAUCE, TRIMMING PULP, AND TOMATO SOUP CHAPTER VIII. A DISCUSSION OF PRESERVATIVE AND NON-PRESERVATIVE CATSUPS; AND THE MOST FREQUENT CAUSE OF INFERIORITY 73 Unfavorable publicity on preservatives—“natural” preservatives—proper acidity—processing catsups—advantage of benzoate catsups—causes of poor color and flavor—advantage of direct conversion of tomatoes into catsup—thickness—spicing and sweetness—“black neck”—general attractiveness. CHAPTER IX. A DISCUSSION OF THE INGREDIENTS OF CATSUP; WHEN AND HOW THEY SHOULD BE ADDED; AND THE AMOUNTS OF EACH PER 100 GALLONS OF FINISHED CATSUP 80 Measuring the volume of tomato juice—amount of tomatoes—keeping batches uniform—use of spices in a sack—use of spices direct and when to add them—use of spices in two batches—what is extracted—storing spices—quality of flavor—use of essential oils—how to add essential oils—paprika—quantities of spices and oils per batch—essential oils economical—adulteration of ground spices—onions and garlic—sugars—sugar syrups—use of sugar in large quantities—salt—vinegar—transference of vinegar—adding the vinegar—acidity—testing finishing point—holding batches—making catsup from pulp—use of benzoate of soda. CHAPTER X. FINISHING, BOTTLING, STERILIZING, AND STORING THE CATSUP 97 The receiving tank and finisher—filling and sealing—washing the filled bottles—processing—advantages of omitting processing—process method—time and temperature—temperature controlling and recording devices—non-process method—which method is the better?—labeling and casing—stacking catsup to avoid “black neck”—packing gallons and No. 10’s. CHAPTER XI. THE MANUFACTURE OF CHILI SAUCE AND THE PULPING OF TOMATO TRIMMINGS 107 Grading the tomatoes—method of handling tomatoes—amount of tomatoes and onions—spices—salt, sugar and vinegar—testing finishing point—filling, sealing and sterilizing—microscopical counts—pulping the trimmings—government attitude on trimming pulp—method of handling tomatoes when trimmings are pulped. CHAPTER XII. THE MANUFACTURE OF TOMATO SOUP 112 Convenience and economy of canned soup—factors upon which success depends—unpalatability—proper sweetness—gradual souring of pulp—sampling—proper acidity—price and quality—microscopical counts—beginning the cook and adding soda—butter, onions, and spices—sugar and salt—testing thickness before adding flour—adding flour—filling and processing—shaking and labeling. CHAPTER I OBTAINING GOOD TOMATO STOCK Value of Good Tomato Stock Obtaining a good quality of tomatoes at a price which is not prohibitive is a problem which in many localities is becoming more difficult to canners and catsup makers each year. Every experienced manufacturer knows that regardless of the expertness with which he may work up his tomatoes into the finished product, he cannot expect to get good quality unless he has good stock to begin with. It is true that by using intelligence and extreme care in the manufacturing processes one manufacturer will make better pulp or catsup from tomatoes of fair quality than another man can get from the best quality of stock. This same care and intelligence applied, however, in working up high quality tomatoes will probably show a greater difference in the finished products than was apparent in the tomatoes from which these products were made; in other words, the goodness of good tomatoes becomes accentuated by the manufacturing process. In order to insure as large a proportion as possible of good quality stock, as well as a good yield per acre in tonnage, manufacturers are each year realizing the necessity of closer co-operation with the farmer. Where in growing tomatoes under contract it was formerly largely up to the farmer to buy his seed and raise his plants and set them out, it is now the usual custom to supply the farmer with seed of the desired variety and of high germination test, and in many cases to go a step farther and supply him with plants six to eight inches high, ready for setting out in the field. Unquestionably, the best results are secured by growing the plants for the farmer. The average farmer does not go about the raising of his plants in an intelligent way, and he will not devote the time to the plant-raising business that it should have. Plant Raising Most packers are agreed that the best plant is raised by starting the seeds in rows in hot beds, transplanting to cold frames when they are two to four inches high to harden them and make them stocky, and again transplanting to the field when the plants are six to eight inches high. This method produces a dark green, bushy, thick-stemmed plant of high vitality, which is so essential to a good yield. What a contrast to the average plant raised by the farmer—the seed often broadcasted, either in a hot bed or in a spot in the garden where the soil has not been specially prepared for plant raising, and when the plants, a large number of which are thin, pale green, and spindly looking, attain a height of anywhere from six inches to a foot they are all set out in the field and allowed to struggle along as best they can. When one looks at the kind of plants that are so often set out he can see at least one reason why yields of from three to seven tons per acre are so often obtained from ground which should yield twice that much, and why the plants are easy victims to blight and other diseases. A prominent canner recently told me that by raising the plants for his farmers he had increased the average yield 4 tons per acre. Use of Fertilizer So many articles have been written on tomato culture for canning plants by experienced horticulturists that the subject will not be dealt with extensively here. In these articles emphasis is usually laid on the desirability of the use of commercial fertilizer, not only to increase the yield, but to hasten the maturing of the crop so that a large proportion of it can be harvested before frost. My experience testifies to the wisdom of this in practically all cases, and with late maturing varieties such as the Stone tomato, in regions subject to early frost, and especially where planted on low ground, it is absolutely essential that fertilizer be used if a good percentage of the crop is to be harvested. Methods in East and West In the Tri-States—that is, Delaware, Maryland, and New Jersey—quite a different situation exists from that in the middle west or far west. The western packer has practically all of his tomatoes grown under contract, while the Tri-State packer, although he tries to contract as much acreage or tonnage as possible at a reasonable figure, is up against the competitive buying of the open market for a large proportion of his raw stock, as there are always a large number of farmers who are willing to gamble that the coming season will be a good one for playing the open market. In this case the buyer usually cannot be as particular about the quality of the tomatoes he buys as can the packer who has his tomatoes all grown under contract at a specified price, and who can exercise supervision over his farmers. This is particularly true in seasons of short crop, when the grower sells his tomatoes on the market and can afford to be very independent, and buyers are wildly forcing up the price by competitive bidding, and taking whatever they can get. Even if the eastern grower is under contract for his entire crop, if the crop is short, and high prices are prevailing on the market, it is the exceptional grower who will live up to his contract, and often to get an excuse for breaking his contract he will deliver very poor tomatoes right along in the hope that they will be objected to, thus giving him the liberty of disposing of them elsewhere. The eastern packer, however, is blessed with a longer season in which to operate. While in the west there are seldom enough tomatoes to justify a run at the factory before August 15th, the Tri-States packer starts in on the early crop about the 25th of July, and his crop is not as liable to be severely injured by an early frost as is the western crop. Canning and preserving plants in the west, being scattered rather sparsely over a very large territory, and being farther away from the large centers of population than in the east, the western packer is able to get a large percentage of his tomatoes hauled to the factory by wagon. This is indeed a big advantage, not only in the saving of freight and handling expense, but in the condition of the fruit when delivered to the factory. Probably having been picked not more than twenty-four hours before delivery, the wagon-hauled tomatoes are solid, and because the skin is not broken by repeated handling, thus preventing the growth of molds, they require very little sorting, in fact, no sorting at all in some cases. A load of tomatoes which requires no sorting at all, however, is unusual. If the packer can get his growers to use spring wagons for hauling tomatoes, it is a big advantage, especially if the fruit must be held any length of time at the factory. If the wagon-hauled tomatoes can be worked up quickly the packer gets 100 per cent value for them, which he very seldom does get on shipped tomatoes, which commonly undergo a loss of between 5 and 20 per cent in shipment, depending upon the time involved in shipment, the ripeness of the fruit, the amount of handling it received, the condition of the weather, the kind of crate in which the fruit is packed, and the amount of ventilation it received in transit. Shipping Tomatoes Shipment by water, although slow, has the advantage of smoothness of transit, and the crates or baskets of tomatoes are not subjected to the frequent joltings of rail shipments, and it is to be remembered that every jolt makes the tomatoes settle to a certain extent in the crates and mashes the tomatoes in the bottom layers. The best car for rail shipments is the slatted car or stock car, which permits of better circulation than any of the other types. A box car should never be used, as it allows the fruit to heat very badly, and there is no circulation of air. The crates in the slatted cars should be so stacked as to allow as much circulation of air through the car as possible. However, care must be taken that the crates are so stacked that they will not shift. A small air space can always be left at the end of every other row on each side without endangering the stability of the crates, and a large air space can be left at the top. Tomato Crates One advantage in the use of the basket over the crate in shipments is the advantage of better circulation of air through the piled baskets of fruit, due to the conical shape of the basket. Good ventilation is thus supplied without danger of the baskets shifting during shipment. The ⅝-bushel basket is used almost universally in the east, while in the west the crate holding a bushel is the common container. The construction of the crate is a more important item than is often thought. The most important point, of course, is strength in construction, and the use of a wood which will not warp easily by alternate soaking and drying out, allowing the nails to become loose and the bottoms to begin to fall out of the crates after a half season’s use. The slats of the crates should have rounded, smooth edges so as not to cut the surface of the tomatoes when they are jolted and weighted down during shipment. The slats should be only close enough together to hold the small tomatoes, so as to permit of as much air circulation as possible. This particularly applies to the bottom of the crates, which become soggy and musty after a little use, and the openings soon become clogged up with tomato substance. It is important to turn a steam hose over the bottoms of such crates to clean them out before returning to the point of shipment. If the empty crates pass along on a chain belt after dumping, this steaming can be accomplished easily. Accumulated decaying tomato substance in the bottom slats not only rots out the crates, but contaminates otherwise good tomatoes every time the crate is used. The crate should also be as shallow as will permit of easy handling, so as to distribute the weight of the tomatoes over as much surface as possible. A shallow, broad crate is preferable to a deep, narrow one. Degrees of Ripeness for Shipping The proper degree of ripeness for tomatoes to be shipped depends, of course, upon the length of time it will take for them to arrive at their destination. Dead-ripe tomatoes will stand very little handling and shipping, particularly if the weather is warm and damp, as it so frequently is during tomato season. It is important, too, not to have the tomatoes delivered to the shipping station too underripe, as they are very apt to rot before they become red enough to cook up into a product of good color. That the employee in charge of receiving tomatoes at the shipping point should be a man of experience and good judgment as well as tact in dealing with the farmers, is apparent. So much depends upon the control he exercises over the farmers in getting them to pick their fruit at the proper degree of ripeness. If he falters, is uncertain, and changes his mind a few times, he is lost, as the farmers soon lose confidence in his judgment. It is always difficult to impress upon the farmer the fact that tomatoes gain in weight during the ripening process, and the riper they have their tomatoes the more they get in dollars when they drive up on the scales. This argument cannot be advanced when the tomatoes are bought by