CHAPTER XIIOLEO OIL AND STEARINE.

Fats — Origin of Butterine — Oleo Oil — Oleo Fats — Selection and Care — Cleanliness and Collection — Chilling Fat — Cooling Water — Melting — Settling the Oil — Clarifiers — Scrap Vat — Seeding or Graining Oil — Press Room — Collecting Oil — Oil Receivers — Temperature of Oil Drawn to Tierce — Stearine — Oil House Yields — Grading Fats — Tests on Oil Fats — Butcher Fats — Mutton Fat — Oil Selection — Oil House Operation.

—The largest item of value in slaughtered cattle is the beef. As already stated, the second largest item is hides. The third item in value is fats. It has been one of the world’s staple articles of trade for centuries and is made use of in the manufacture of many kinds of articles for man’s use, from those of comfort to those of destruction, perhaps only displaced in its multitude of uses by the one raw product, coal tar.

—Prior to the Franco-Prussian war, or in 1871, fats were used almost exclusively for soap making and other manufacturing purposes, comparatively little of it being used for food purposes. During the siege of Paris a reward was offered to anyone who would find a substitute for butter. A French scientist reasoned as follows: Careful observation teaches that a cow that is fat and in good health makes better butter and more butter than one of the same quality that is poor and emaciated, hence it must follow the cream of the milk, or the “butter-fat,” is in reality nothing more or less than Nature’s surplus fat in the animal, and that in all cattle that are fed each day more than the requirements to build up the broken-down tissues a surplus fat is deposited.This fat, the chemist decided, was as much a natural butter as though it had been skimmed from milk, and starting on this theory originated the manufacture of oleomargarine.

—The creating of this industry has meant millions of dollars to this country in returns that have been made from the sale of fats prepared into oil for manufacturing oleomargarine instead of being melted into tallow for soap making and other purposes.

—Oleo oil is the name of one of the principal ingredients used in making oleomargarine, or imitation butter. The fat is put through a hasher, which thoroughly disintegrates it, cutting the tissue so that the oil is made free when heated.

—The fats used for the manufacture of oleo oil are usually all the fats removed when the animal is slaughtered, including the “caul” fat or that fat surrounding the “omentum”; the ruffle fat, which is that fat surrounding the intestines, and to which the “runners” or round gut is attached; the heart casing, and fats attached.

—It is reasonable to suppose that all of these fats are of the same quality, but in the handling of this, during the course of slaughtering and treatment thereof, some of it necessarily becomes unfit for oleo oil purposes, and is used in tallow. The amount used for tallow is regulated by the care and intelligence of the men in charge, and if properly handled a very small percentage of the fat in the animal should find its way to the tank house, as it nets much better results when put into oleo oil, as will be noted from the tests hereafter submitted.

—The fats, as rapidly as removed from the animal, should be taken quickly in clean utensils and washed in medium temperature water to remove any blood present. Thorough chilling of the fat is a very essential feature in making oleo oil. In order that this may be done it is necessary that the fat be cut in small pieces, so that the cold water can get at every part of it. A machine illustrated inFig. 53is used for cutting the fat before passing it into the cold water. The water is circulated by the use of a pump and distributed over the fats from a perforated pipe.

—The fat, while chilling, should be allowed to remain in cold water for about five hours, or until it has become thoroughly chilled. Precaution should be taken to see that no fat goes to the hasher, or melting kettle, until it is thoroughly chilled. Failure to do this is not particularly noticeable in the oleo oil when made, but soon afterward results in a deterioration of the oil. It is never objectionable to hold the fat from twelve to twenty hours, if necessary, in the cold water, although five hours is sufficient. The constant submergence of the fat by mechanical means or by hand is of prime importance.

FIG. 53.—OLEO FAT CUTTER.

The fats are ladled or forked from the chilling vat and placed on a table to drain. The dryer the fat the better, but it must not lay unduly long to drain. From this table they are passed through an Enterprise steam jacketed hasher for grinding. Steam is kept on the jacket to assist in rapidity in passing it through the hasher.

—The chilling or cooling of water is accomplished in two ways, by the introduction of ice or the cooling of the water or by submerging pipes in the tanks, and circulating chilled brine or ammonia gas through the pipes, same being a part of the refrigerating system. In the latter case the pipes should be covered by a removable screen to prevent fats attaching to the pipes.

FIG. 54.—KETTLE FOR MELTING FATS FOR OLEO OIL.

—The fat when hashed is passed to an open top water jacketed kettle of the type shown in the illustration,Fig. 54.

Just previous to beginning to hash the fat into the kettle the stirrer is placed in motion. The water in the jacket is heated up to a temperature of about 180° F.

When the kettle is partially filled and as the fat accumulates, it will collect and hang to the stirring gear. To meet this condition the stirring gear is arranged to rise vertically on the shaft by lifting and assistance of the counterweight attached to it. The fat is removed by the use of a paddle, the stirrer lowered and started in motion. The fat is mixed with a large paddle so that the melting oil at the sides and bottom of the kettle is freely intermingled with the partially melted fat.

The mass gradually assumes a murky yellow appearance as the oil is made free. The man in charge of melting uses a bath thermometer constantly and regulates the temperature of the water in the jacket by the admittance of cold water to chill it or steam to warm it so that the temperature of the melting oil does not exceed 156° F. It usually takes 1¹⁄₂ hours to properly melt the contents of a full kettle. When the melting is complete the stirrer is raised out of the oil and allowed to remain raised while the oil is settled.

—When the oil comes to rest about twenty pounds of fine salt is scattered over the surface, thrown in moderate handfuls so as to sprinkle the entire surface. This salt in settling clears the oil by carrying down the floating fibre by mechanical as well as chemical action. The oil usually has a scum on top and this is gently skimmed off and saved as a bottom for the next kettle. After settling about fifteen minutes the oil is run off by gently lowering the hinged pipe, the oil as de-canted is passed to the clarifier.

When the pure oil is run as low as can be conveniently done without carrying off any scrap of settlings, the oil laying on the surface of the water and sediment in the bottom is passed to some receptacle and sent to the pressure tanks. The kettle is well scrubbed, made clean and the skimmed bottoms deposited ready for filling again with hashed fat.

FIG. 55.—SETTLING KETTLE FOR OLEO OILS.

—Each kettle is provided with two clarifying or settling kettles. These are cone-shaped tanks in which the oil from one melting kettle is deposited. The oil is allowed to stand as long as possible in a quiet state and the sediment or fibre collects in the bottom of the cone. This is withdrawn at the bottom at frequent intervals so asto free the oil from sediment and dirt. The temperature of the oil carried in the clarifiers is 140°, kept uniform by use of warm water in the jacket.

After settling the oil about two hours it is drawn to the seeding trucks. Cotton flannel bags are usually put on over the outlet pipe so as to strain the oil and collect any floating pieces of tissue that would otherwise pass to the seeding truck.

—A vessel which requires attention and in which the yield in the oil house can be very materially increased and improved by proper handling is the scrap vat. After the vat is melted and the oil siphoned off, the balance or residue in kettle is drawn out of the bottom into the scrap vat, which is located directly under the melting kettle. This kettle should be kept full of hot water at a temperature of about 130° F., and when the scrap is dropped in the oil will immediately come to the surface; this should be skimmed off promptly, for if it is allowed to lie in the scrap vat a bad flavor will result and it will then have to be sold as an inferior grade of oil; but if skimmed as stated this strong flavored feature may be avoided.

When through melting for the day, the steam should be turned on the scrap vats to bring them up to a temperature of 190° to 200° F. This will release any fat yet remaining in the scrap, which should be skimmed and used for a lower grade of oil, as it will have a strong flavor. The balance of the scrap is then sent to the tank house, where it is cooked under pressure and the remaining oil taken out.

—The oil when settled in the clarifiers is passed to the seeding or graining trucks. The seeding truck plays a very important part in the handling of oleo oil and is one of the points where a great deal of trouble can be developed if not properly watched.

When the oil is drawn into the seeding trucks there should be no signs of any water. If there is any water left in the oil it naturally settles to the bottom of the seeding truck. The oil usually being at a temperature of 120° to 125° F., and it being three and sometimes four days before it is cooled, the heat held in the oil, together with the water and sediment that may be in the bottom, causes a decomposition and the resultis “sour bottoms,” which are very offensive. If any of this sour material has gotten into the press, the stearine will be spotted and out of conditions. The oil will also show it more or less, so that it is absolutely necessary that this particular point be given very close and careful attention.

FIG. 56.—OLEO SEEDING TRUCK.

—It has for many years been considered necessary to line the seeding truck with galvanized iron, in fact many of the large melters today are using this style of truck. The seeding truck, however, which gives the best results is a wooden truck (seeFig. 56) without any lining, made of basswood, or whitewood, which are odorless, and can be readily cleaned and kept sweet. The objections to a truck lined with galvanized iron might be summarized as follows:

In the first place, considerable salt is used in the material, more or less of which is left in the oil. When the melted fat is drawn off into the seeding trucks and is left to stand for three or four days, this salt attacks the iron, and if not watched very carefully small pin-holes will be eaten through the iron, the result being that the galvanized iron pan will leak into the wooden box proper. Again, every time the seeding trucks are emptied, they are thoroughly washed and steamed out andmore or less of this water for washing finds its way in between the lining and the wooden box. When the seeding truck is filled with oil, the weight of the oil causes this water, which is held between the iron and the wood, to ooze into the oil, causing “sour bottoms.” This particular point has caused the loss of a great many thousands of dollars in the manufacture of this product, even though it is apparently a very unimportant matter.

—In using wooden seeding trucks, attention is called to a very important item to be considered, and if not carefully looked after the results will be unsatisfactory. The oil is drawn into seeding trucks at a temperature of about 120° to 125° F., which will shrink wood very rapidly, therefore the trucks should be made out of thoroughly kiln-dried lumber, which should beextrakiln-dried. The bottom and sides of the truck are bolted together with a bolt running through them and one on either end, so that any shrinkage of the wood can be taken up. The same is true of the sides of the truck. In each of the joints, after they are perfectly made, a strand of wicking should be put in between the edges, so that when it is drawn down it forms a perfect packing. As is well understood, the shrinkage of wood is mostly crosswise of the grain, there being very little lengthwise; thus it will be seen that the wood in these trucks, both at the sides and at the ends, must be put in so that it will all shrink uniformly. The bottom of the truck will naturally shrink sidewise and if the bolts are drawn up it stops the opening, while if the sides of the truck shrink, the bottom bolts can be drawn up, readily stopping the leak. The ends of the truck must have the grain running up and down instead of crosswise, for if the bottom of the truck joins sidewise and the end pieces are running crosswise of this grain, it will be impossible to draw the bottom up tight, on account of the lack of shrinkage of the ends where the grain runs lengthwise of the end.

FIG. 57.—KNUCKLE TYPE OLEO OIL PRESS.

—The room into which the seeding trucks with their contents are run should be held at a temperature of 75° to 90° F. The material in the seeding trucks, which is now called “stock” should be pressed at a temperature of from 78° to 84° F., according to its quality, as well as to the percentage of stearine which it is desirable to make. The lower the temperature at which the oil is pressed the more stearine will be retained in the cloths. After the stock is chilled to above temperature it will be found that a granulation has taken effect and oil will be observed on the top, whereas the heavier and granulated parts of the fat will be at the bottom. This should be thoroughly mixed up before it is sent to the press, either by use of a dipper or mechanically, care being used not to disturb the bottom of the cooler. If there is any moisture in the bottom of the truck it would spoil the stock by mixing it. Whereas, if it is not agitated, when the stock is removed, the bottom can be examined, and, if it isgood, it can be used; otherwise it should be sent to the tallow tanks. After the stock is thoroughly broken up or mixed it is ready for the press, it first being wrapped in cloths.

The cloth used in connection with this press is a medium weight piece of cotton canvas, which is cut in the proper sized pieces, about eighteen inches square. The cloth is first put on the “former” which is filled with a dipper full of stock; the attendant wraps it up carefully and the man filling the press as it comes around in the wheel, takes the wrapped stock and lays it on the plate, using eight bags of stock on each plate in the press, generally using sixty steel plates for each press. When the press is full the power is turned on. The slow speed should be used almost exclusively after the press is started in order to give the oil sufficient time to strain through the canvass.

FIG. 58.—OLEO OIL RECEIVER.

—The oil from the press should run to a receiving tank, as many being used as is necessary to keep the different grades of oil separated. Where oil is being made in large quantities it is always advisable to have the receiving tank hold sixty tierces, or a car load of oil, for if smaller receivers are used the oil is likely to be irregular.

The quality of oil varies, as does the quality of cattle; for instance, choice native cattle, which are very fat, make a finer, better oil than western cattle which are not in as good condition,and as the killing is always liable to run irregular, if the oil is not assembled in large quantities, it is often perceptible, and a manufacturer soon acquires the reputation of making irregular oil. When that reputation is once established buyers scrutinize closely before making purchases.

—The receivers of the oil should be either jacketed or have a boat bottom; that is, one vat placed inside of the other (seeFig. 58), so that the temperature of the oil in the receivers may be regulated, but under no conditions should steam pipes be submerged in oleo oil; all heating should be done by contact surfaces with hot water. In having the vat made with a boat bottom it is simply necessary to fill up the space with water and turn on steam, holding the water at the desired temperature.

—The oil in the receiver, when ready to be tierced, should be raised to a temperature of from 116° to 118° F., and then drawn off, the tierces being filled through a side bung hole. After the tierce is filled it should be rolled away and left undisturbed in a temperature of 50° F. for at least four days. The oil thus handled will show a granulation, which is very desirable. If the oil is not allowed to stand until it has thoroughly granulated, or “seeded” it will come out smooth or pasty, and pasty oil is very objectionable to the purchaser. If the oil is not drawn off at this temperature it will be found difficult to have it seed properly, as it chills too quickly for a good granulation to take effect. It is not wise to draw the oil into a temperature lower than 50° F. After the oil has been seeded it can be kept in any storage that is available below 60° F., but it must be put into the refrigerating temperature for the first three or four days, and not at any time carried at a temperature below 45°.

—Stearine is the product left in the cloths after pressing the stock. This product is used for many purposes, but largely for the manufacture of compound lard on account of its hardness. (Ordinary tallow will run 41¹⁄₂ to 43; oleo oil runs 40 to 42; oleo stearine should run 50 to 52, titer.)

After the oil is thoroughly pressed out, the press is opened and the stearine taken out of the cloths. The stearine should be thrown into a bin where there is an abundant circulationof pure air, in order to thoroughly cool, for if it is put into the package too warm, a mold will form which deteriorates it and reduces its value. After it is thoroughly chilled it is put into packages, compressed by a machine as shown, which saves labor and puts more material into the package; or pounding it with a maul as it is deposited in the tierces.

FIG. 59.—STEARINE PACKER.

—Stearine, after being put in packages,can be held for thirty days in ordinary storage. If held longer than that, it should be put into a room kept at a temperature of from 40° to 45° F. and which is perfectly dry. Stearine, generally speaking, is a very unsatisfactory article to carry any length of time, for, in pressing, any moisture which may be in the stock is left in the stearine, and if carried for some time this moisture produces a discoloration, which is known to the trade as “spotted stearine.” It also causes a moldy or musty smell, which injures it for edible purposes, and while it is often carried for months for an anticipated rise in the market, it is quite as often regretted that it was not sold when it was in good condition for the market.

—Stearine is always packed in slack packages, the regular package being 34 inches high, 90 inches in circumference at the bilge and 23⁵⁄₈ inches across the head with eight patented hoops. Oleo oil is always put into a special tierce which is 34 inches high, 81 inches in circumference at bilge and 21 inches across heads, with six iron hoops.

—The yields of oleo oil and stearine from stock are regulated largely by the prices of the different articles, as, for instance, when oil is low and stearine is high it is advisable to press the stock at a lower temperature, making all the stearine possible. Reverse the conditions and it is advisable to press the stock at a high temperature, making all the oil possible, hence the general yield of oil in stearine is largely regulated by the price of the two.

—As the different kinds of fat have more or less different flavors, it is wise to make careful selections in order to get the best results, it being impossible to make a grade of all No. 1 oil, 10 or 15 per cent of the total being No. 2. The balance of the product, eliminating the 10 or 15 per cent should be strictly No. 1 oil, but if the whole output is made into one grade, it would not be acceptable as No. 1. Hence it will be seen that it is the better part of wisdom to make two and sometimes three grades of this product, as indicated above.

Of all the oleo oil made in this country, 75 to 90 per cent is shipped to Holland, where it is made into butterine and distributed throughout the continent and England. The requirementsof these consumers seem to have changed within the last few years, and the melters of oleo oil strive to get the oils in the condition to best suit the Hollanders’ demands. What they seem to require is, first of all, a very neutral oil, or in other words an oil with as little flavor and smell as possible, whereas only a few years ago just the opposite was the case, and the whole endeavor at that time was to get an oil with as much flavor as could be made. In grading the fats a neutral or No. 1 oil is obtained from the following parts:

For a No. 2, or second grade, which, though it may realize nearly as high a price as the first oil, is an oil of high flavor, the following parts are used:

A third grade of oleo oil, which will be quite inferior to either of the other two named, but for which at times there is a good demand, often netting more than the same product would, if made into rendered tallow, is made from the following trimmings:

If fat is graded as above suggested, and handled properly in the different departments in the oleo house, satisfactory grades of oil should be made.

—The following are tests showing the pounds and percentages of yield of different kinds of fat when made into oleo oil. The tables, as will be noted, only show the percentages of fat in oleo stock, this consisting of the oil and stearine before pressing.

TEST NO. 1.Caul fat run to No. 1 oleo oil:Hot weight from beds (dry)1,505 lbs.Chilled twenty hours, net weight1,937 lbs.Gain from hot weight28.70% = 432 lbs.Weight of chilled fat to oil house1,937 lbs.Thisfat, hashed into melting kettle, cooked one hour and five minutes, settled one hour, drawn into receiver, settled two hours, and drawn into coolers, gives following:Yield of oleo stock1,238 lbs. ={82.26% from hot weight63.91% from chilled weightRuffle fat run to No. 1 oleo oil:Hot weight from beds (dry)1,518 lbs.Chilled twenty hours, net weight1,735 lbs.Gain from hot weight14.29% = 217 lbs.Weight chilled fat to oil house1,735 lbs.Thisfat, hashed into melting kettle and cooked one hour then settled one hour fifteen minutes, after which drawn into receiver and again settled for two hours, and drawn into cooler, gives following:Yield of oleo stock1,018 lbs. ={67.06% from hot weight58.67% from chilled weight

TEST NO. 1.

Caul fat run to No. 1 oleo oil:

Hot weight from beds (dry)1,505 lbs.

Chilled twenty hours, net weight1,937 lbs.

Gain from hot weight28.70% = 432 lbs.

Weight of chilled fat to oil house1,937 lbs.

Thisfat, hashed into melting kettle, cooked one hour and five minutes, settled one hour, drawn into receiver, settled two hours, and drawn into coolers, gives following:

Ruffle fat run to No. 1 oleo oil:

Hot weight from beds (dry)1,518 lbs.

Chilled twenty hours, net weight1,735 lbs.

Gain from hot weight14.29% = 217 lbs.

Weight chilled fat to oil house1,735 lbs.

Thisfat, hashed into melting kettle and cooked one hour then settled one hour fifteen minutes, after which drawn into receiver and again settled for two hours, and drawn into cooler, gives following:

The second test is similar, except that it is made on the “peck and reed” fat, which is used in a No. 1 oil.

In the third test chipped fat is used for No. 1 oleo. This is a fat which is cut off the middle gut, when fatted.

Test No. 4 is made on the gut end fat, which consists of miscellaneous trimmings from the gut, ends, etc.

No. 5 was a test to determine the value and yield of caul and ruffle fat from 165 cattle.

TEST NO. 2.Peek and reed fat to oleo oil:Hot weight from trimming bench (dry)1,082 lbs.Through small wash vat to wash (weight from water)1,211 lbs.Gain in washing from hot weight11.92% = 129 lbs.Weight to chill vat1,211 lbs.Chilled sixteen hours, weight1,255 lbs.Gain from washed weight44 lbs.Gain in chilling from hot weight15.90% = 172 lbs.Weight chilled fat to oil house1,255 lbs.Handled in the usual way gives following:Yield of oleo stock727 lbs. ={67.19% from hot weight60.03% from washed weight57.93% from chilled weightTEST NO. 3.Chip fat to No. 1 oleo oil:Hot weight from trimming bench (dry)1,500 lbs.Through small vat to wash (weight from water)1,639 lbs.Gain in washing from hot weight9.26% = 139 lbs.Weight to chill vat1,639 lbs.Chilled eighteen hours, weight1,760 lbs.Gain from washed weight7.38% = 121 lbs.Gain in chilling from hot weights17.33% = 260 lbs.Weight chilled fat to oil house1,760 lbs.Handled in the usual way, gives following:Yield in oleo stock981 lbs. ={65.40% from hot weight59.85% from washed weight55.74% from chilled weightTEST NO. 4.No. 1 gut end fat to oleo oil:Net weight from trimming bench (dry)1,347 lbs.Through small vat to wash (weight from water)1,514 lbs.Gain from hot to washed weight12.40% = 167 lbs.Weight to chill vat1,514 lbs.Chilled twenty hours, weight1,532 lbs.Gain from washed weight1.19% = 18 lbs.Gain to chilled from hot weight13.73% = 185 lbs.Weight of chilled fat to oil house1,532 lbs.Handled in usual way gives following:Yield of oleo stock827 lbs. ={61.39% from hot weight54.62% from washed weight53.98% from chilled weightTEST NO. 5.Test on caul and ruffle fat:Total weight5,252 lbs., av. wt. per head, 32 lbs.Yield “A” oleo oil52.38%=2,751lbs. at$8.15per cwt.$224.21Yield No. 1 stearine22.92%=1,204lbs. at8.65per cwt.104.14Yield skimmings to No.3 oil1.71%=90lbs. at6.40per cwt.5.7677.01%Yield scrap to tank421lbs.Yield tallow19.24%=81lbs., at$ 4.60per cwt.3.73Yield tankage (dry)3.80%=16lbs., at$17.50per ton.14$337.98Value per cwt. of fat$6.43Value per head of fat2.05

TEST NO. 2.

Peek and reed fat to oleo oil:

Hot weight from trimming bench (dry)1,082 lbs.

Through small wash vat to wash (weight from water)1,211 lbs.

Gain in washing from hot weight11.92% = 129 lbs.

Weight to chill vat1,211 lbs.

Chilled sixteen hours, weight1,255 lbs.

Gain from washed weight44 lbs.

Gain in chilling from hot weight15.90% = 172 lbs.

Weight chilled fat to oil house1,255 lbs.

Handled in the usual way gives following:

TEST NO. 3.

Chip fat to No. 1 oleo oil:

Hot weight from trimming bench (dry)1,500 lbs.

Through small vat to wash (weight from water)1,639 lbs.

Gain in washing from hot weight9.26% = 139 lbs.

Weight to chill vat1,639 lbs.

Chilled eighteen hours, weight1,760 lbs.

Gain from washed weight7.38% = 121 lbs.

Gain in chilling from hot weights17.33% = 260 lbs.

Weight chilled fat to oil house1,760 lbs.

Handled in the usual way, gives following:

TEST NO. 4.

No. 1 gut end fat to oleo oil:

Net weight from trimming bench (dry)1,347 lbs.

Through small vat to wash (weight from water)1,514 lbs.

Gain from hot to washed weight12.40% = 167 lbs.

Weight to chill vat1,514 lbs.

Chilled twenty hours, weight1,532 lbs.

Gain from washed weight1.19% = 18 lbs.

Gain to chilled from hot weight13.73% = 185 lbs.

Weight of chilled fat to oil house1,532 lbs.

Handled in usual way gives following:

TEST NO. 5.

Test on caul and ruffle fat:

Total weight5,252 lbs., av. wt. per head, 32 lbs.

The prices on oil, stearine and skimmings are the market prices at time test was made, less department expense for 60 cents per 100 pounds. The price on tallow is market price less 40 cents per 100 pounds, department expense.

The following is a test of tripe fat made into No. 1 oleo stock:

TEST NO. 6.Tripe fat to oleo oil:Hot weight from trimming bench (dry)1,639 lbs.Through small vat to wash (weight from water)1,860 lbs.Gain in washing from hot weight13.48% = 231 lbs.Weight to chill vat1,860 lbs.Chilled twenty hours, weight2,009 lbs.Gain from washed weight8.01% = 149 lbs.Gain in chilling from hot weight22.57% = 370 lbs.Weight chilled to oil house2,009 lbs.Handled in the usual way, gives following:Yield in oleo stock,1,070 lbs. ={65.28% from hot weight57.53% from washed weight53.45% from chilled weight

TEST NO. 6.

Tripe fat to oleo oil:

Hot weight from trimming bench (dry)1,639 lbs.

Through small vat to wash (weight from water)1,860 lbs.

Gain in washing from hot weight13.48% = 231 lbs.

Weight to chill vat1,860 lbs.

Chilled twenty hours, weight2,009 lbs.

Gain from washed weight8.01% = 149 lbs.

Gain in chilling from hot weight22.57% = 370 lbs.

Weight chilled to oil house2,009 lbs.

Handled in the usual way, gives following:

—Kidney fat yields the largest percentage of stock of any fat in the animal. The fat in this particular part seems to be richer in oil and in the general handling of same it rarely goes into the water to absorb additional weight, as it is generally purchased from the retail butcher after the carcass has been cut up. This in itself is a large branch of the business, in many places melters making a practice of collecting from the butchers their bones, tallow and fat. Thefollowing test will give an idea of the yield of the different products brought from a butcher’s shop, when used in an oleo factory or tank room. The prices quoted are those that were paid at the time tests were made. The percentages, however, are accurate.

STOCK YIELD FROM 649 POUNDS OF KIDNEY AND COD FAT.Stock507 lbs., or 78.12%, at 9¹⁄₂c per lb. =$ 48.16ExpensePkgs., $1.45; labor, $1.27 =2.72Net value$ 45.44Value per 100 lbs., based on weight of fat, $7.00.STOCK YIELD FROM 2,004 POUNDS OF PICKINGS.Stock1,124 lbs., or 56%, at 9¹⁄₂c per lb. =$106.78ExpensePkgs., $3.83; labor, $5.01 =8.84Net value$ 97.94Value per 100 lbs., based on weight of fat, $4.89.TALLOW YIELD FROM 10,787 POUNDS OF BONES.No. 1 tallow1,513 lbs., or 14.02%,at 6¹⁄₂c per lb. =$ 98.34Stock of tankage1,750 lbs., or 16.22%,at $16 per ton =14.00Waste7,524 lbs., or 69.76%.Expense, labor2.25Net value$110.09Value per 100 lbs., based on weight of raw bones, $1.02.SUMMARY.Per100 lbs.Net value kidney and cod fat$7.00Net value pickings4.89Net value bones1.02Net value kidney, cod and pickings combined5.40Net value kidney, cod, pickings and bones combined1.89

STOCK YIELD FROM 649 POUNDS OF KIDNEY AND COD FAT.

STOCK YIELD FROM 2,004 POUNDS OF PICKINGS.

TALLOW YIELD FROM 10,787 POUNDS OF BONES.

SUMMARY.

The above is based on green weights. No deductions for steam power and administrative expenses.

The following is the percentages of products used in above test:

—The following is a test on the scrap from foregoing test after all the oil had been extracted, which was put into a rendering tank and cooked for twelve hours with forty pounds pressure:

TEST ON OLEO SCRAP.

—The fat derived in the killing of sheep is often used to good advantage in making mutton oleo oil. There are times when there is a ready sale for this oil, in which event it is run in the oil house by precisely the same rules as those laid down for the melting of beef tallow. The yields on mutton fat are considerably less, however, than on beef fat. When it is not advisable to put it into mutton oleo, it is nearly always advisable to make a mutton tallow, providing there is sufficient amount of the raw stock on hand to warrant it, as mutton tallow invariably brings a better price than ordinary commercial tallow. Mutton tallow runs considerably higher in titer than ordinary tallow. It is also much whiter and is often used in the manufacture of cosmetics, etc. When made into oil it should be made from mutton fat only. Many lard refiners have discovered that where a complaint was made regarding the quality of their lard it was traceable to their oleo stearine, in which mutton fat had been used, this fat having a tendency to turn the lard rancid much earlier than where beef oleo stearine is used.

—In some establishments where high colored oils disposing toward a yellow tint are produced, they are selected separately in the seeding room and the oil segregated on account of its desirability for domestic butterine.

—The following instructions if complied with will result in a satisfactory operation.

—See that the fat is in good condition, properly trimmed, all pieces of meat, lungs, guts, etc., completely removed, and that the fat is handled promptly, not allowing it to become stale, and sour before it is received.

—When it is received, don’t pile up in the vats; see that the ice water is in contact with all parts of it and thoroughly chill it. When caul fat is extra heavy, examineall the largest pieces closely and see that they are thoroughly chilled through.

—Arrange to have no ice or cooling pipes in the vat where the fat is received, it being thrown in here to give it a thorough washing. The next vat to which it is thrown, however, should have cooling pipes. The water in the vats into which the fat is washed and chilled must be changed daily.

—Do not begin hashing until the fat is properly cooled. It will take from three to five hours to accomplish this, under ordinary conditions.

—It is wise never to begin hashing until there is fat enough to either finish the day’s work, or at least to keep the house running and to hash a kettle full regularly, as it is impracticable to stop in the middle of the operation of hashing a kettle of fat, for when once commenced it must be completed.

—Use sufficient steam on the hasher jacket to facilitate the cutting, having the material come through as cold as possible. If too much steam is used it partially melts the fat in the hasher and disintegration is not perfect.

—For melting kettles which hold about 1,400 pounds of hashed fat about half an hour should be required to do the hashing. While the capacity of the hasher might be much greater it is well to have the fat partially melted during the course of hashing, so as not to have too large a body of unmelted fat in the melters.

—The time for melting, settling and letting down the stock into the clarifiers from the melting kettles should not exceed two hours and twenty minutes. As soon as hashing is begun, the agitator should be started revolving. When through hashing, the man overseeing the melting, after allowing the agitator to run five or ten minutes, should lift it out of the kettle and clean it off thoroughly with a paddle, and then drop it back into the kettle. If this is not done several times during the course of hashing, unmelted fats will be found in the bottoms when they are ready to drop to scrap vat.

The steam should be turned on in the jacket of the kettle as soon as hashing is started. Keep the steam on until thefat shows a temperature of 140° to 142° F. The steam should then be shut off and the surplus heat in the kettle will run the fat up to 155° F., which should be the maximum melting point for No. 1 melting oil. No. 2, or the flavored oil, may be melted to 158° F. No. 3, or lowest grade of oil, may be melted at 160° F., and in some instances 165° F.

As soon as it is evident that the fat is thoroughly melted the agitator should be stopped and pulled out of the oil, and it should stand at least an hour, the steam being shut off from the jacket, giving it a chance to settle. On this particular process depends the entire result of the making of oleo oil, as the fat being so thoroughly disintegrated in the hasher when it is melted, a great deal of tissue from this fat is held in suspension in the oil and it must have very careful handling in order to get it thoroughly settled out. If it is not all removed from the oil, the latter will turn strong from the decomposition of the tissues.

After the oil has settled throw in about fifteen to twenty pounds of fine salt, scattering it thoroughly over the surface of the oil, the salt having the effect of carrying with it any unsettled tissues which may still remain in the oil. The top of the oil should then be carefully skimmed, for there is a scum floating on the top when it is settled. After this is done the siphon pipe is dropped down into the oil and the oil is taken off very carefully. It is very essential in drawing this with the siphon pipe that as little scrap and water as possible be taken with it. After the oil has been taken off, the bottom valve of the melting kettle is opened, dropping the contents into the scrap vat. The kettle should be thoroughly washed and cleaned before it is used again.

—The oil now in the clarifier should be kept at a temperature of about 140° F. It should be allowed to remain in the clarifying kettle about an hour, and during this time should lose about ten degrees in temperature, perfect settling being possible only by lowering the temperature of the material. While oil is in the clarifier, sprinkle about four pounds of salt over it. As soon as it is settled skim immediately, and again a second time before the oil is drained into seeding truck.

It should be drawn off into the seeding truck at a temperature of 120° to 125° F., care being taken at all times in siphoning the oil from the different kettles to see that no water has gotten into the oil. As it is impossible to draw the oil all out of the different kettles with the siphon, the oil that is left in the bottom of the kettle each time should be taken back and put into the melting kettle and allowed to run through with the next melting of fat.

—Be particular to have the kettles washed each time after being emptied and see that they are kept at proper heat to receive each lot of fat when ready.

—See that all water, siphon pipes, and drawing-off pipes to the seeders be thoroughly scalded and steamed out before drawing, as there is invariably an accumulation in these pipes, which, if allowed to go uncared for, will turn rancid and injure the quality of the oil.

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