PORK SLAUGHTERING, CUTTING, PRESERVING, AND COOKING ON THE FARM TEXT

PORK Slaughtering, Cutting, Preserving, and Cooking on the Farm UNITED STATES FARMERS’ _PREPARED BY_ DEPARTMENT OF BULLETIN SCIENCE AND AGRICULTURE NUMBER 2265 EDUCATION ADMINISTRATION CONTENTS Page Selection and Care of Animal before Slaughter 3 Preparing for Slaughter 4 Slaughter 7 Chilling the Carcass 35 Cutting 36 Freezing and Frozen Storage 53 Further Processing 54 Meat Cookery 62 Precautions 63 Other Publications 64 Issued June 1978 Slightly revised April 1981 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 Pork Slaughtering, Cutting, Preserving, and Cooking on the Farm By H. Russell Cross, _Research Food Technologist_,[1] E. Curtis Green, _Meat Marketing Specialist_,[2] William R. Jones, _Extension Meat Specialist_,[3] Roger L. West, _Associate Professor, Meat Science_,[4] and Anthony W. Kotula, _Chief, Meat Science Research Laboratory_,[1] (Photographs by Donald K. Rough[1] and Terry K. O’Driscoll[5]) [1] Meat Science Research Laboratory, Northeastern Region, SEA-FR, Beltsville, Md. 20705. [2] Standardization Branch, Meat Quality Division, Food Safety and Quality Service, Washington, D.C. 20250. [3] Cooperative Extension Service, Auburn University, Auburn, Ala. 36830. [4] Department of Animal Science, University of Florida, Gainesville, Fla. 32611. [5] Beltsville Agricultural Research Center, Northeastern Region, SEA-FR, Beltsville, Md. 20705 SELECTION AND CARE OF ANIMAL BEFORE SLAUGHTER Several factors should be considered before slaughtering a hog for home consumption. The most important considerations are health, kind of animal (barrow, gilt, sow, or boar), expected meat yield, and care of the animal prior to slaughter. Health You should take care that an unhealthy animal is not selected for slaughter. At the time of selection, look for signs of sickness such as fever, increased breathing rate, and diarrhea. Animals suspected of being unhealthy should be treated by a veterinarian until the animal is returned to a healthy state. Animal Care It is important to exercise proper care of the animal prior to slaughter, if you expect to obtain high quality meat. Pen the animal in a clean, dry place the day before slaughtering. Restrict the animal from feed 24 hours prior to slaughter, but provide access to water at all times. The slaughter of hot, excited animals increases the risk of sickness, injury, and darker meat; therefore, do not run the animal or wrestle with it. Bruises and whip marks cause bloody spots which must be trimmed out. Animal Type and Meat Yield Highest quality pork is produced from young, healthy, well-fed, meaty hogs that weigh from 175 to 240 pounds. The meat-type hog should have full, plump, meaty hams and straight, smooth sides. Fat should be firm, evenly distributed, and not more than 1.6 to 1.7 inches average thickness over the back. The average meat-type hog produces as much pork as a family of two consumes in 10 to 12 months. Heavier, fatter hogs produce less lean and more excess fat. A meat-type hog, when cut and trimmed according to the methods described later, will yield approximately 65 to 70 percent of its carcass weight in ham, picnic shoulder, loin, bacon, and Boston butt. Expected yields of major and minor cuts from a U.S. No. 2 hog are presented in table 1. Table 1._—Percentages of major and minor cuts from a U.S. No. 2 hog, trimmed according to USDA procedures_ ------------------------------------------------------------------- Cuts Percentage of USDA carcass weight ------------------------------------------------------------------- Ham (trimmed) 19 Belly (untrimmed) 18 Collar, fat back, and clear plate 18 Picnic shoulder and Boston butt (trimmed) 17 Loin (trimmed) 17 Feet, tail, and neckbones 5 Spareribs 3 Jowl (untrimmed) 3 ----------- 100 ------------------------------------------------------------------- Four lean cuts[1] 53 Adapted from Smith, King & Carpenter, 1975. [1] Ham, loin, picnic shoulder, and Boston butt. The slaughter of boars is not recommended. Meat from boars has a strong odor during cooking, and an off-flavor. This “sex” odor and flavor is often identified as being “soapy,” and the odor increases as boars approach sexual maturity. If old boars are to be slaughtered, they should be castrated and allowed to heal prior to being slaughtered. PREPARING FOR SLAUGHTER Prior to the day of slaughter, select the slaughter site, accumulate all equipment, prepare for waste disposal, and, if necessary, arrange with a local processor or meat market for chilling and cutting the carcass. If you plan to have the carcass chilled and cut up, make arrangements concerning the time and day on which the carcass can be accepted, the charges, and specific instructions for chilling, cutting, and wrapping. Site Selection Slaughter site selection is extremely important. The amount of space and equipment needed will depend on the method (scalding or skinning) used. If the carcass is to be scalded, be sure that a site is selected where a fire can be built, and clean, running water is available. If a tree is to be used to suspend the carcass, select a healthy limb, 6 to 8 inches in diameter and 8 to 10 feet from the ground. This will ensure that the limb will not break from the weight of the carcass, and the carcass can be fully extended above the ground for viscera removal and splitting. If the animal is to be slaughtered in a building, be sure that a strong beam 8 to 10 feet from the floor is available. The floor should be clean and, preferably, concrete. After selection of the slaughter site, clean up the area to ensure that leaves and dirt are not blown on the carcass during slaughter. If the site has a wooden or concrete floor, wash the floor and all equipment with plenty of soap and water. Be sure to rinse thoroughly because sanitizers discolor the meat and may cause off-flavors. If animals are to be slaughtered outdoors, use straw to cover the area where the carcass will be suspended and eviscerated. The weather on the day of slaughter should also be considered. During hot weather, the animal should be slaughtered during the cooler early morning or late evening hours. Since an inexperienced person will take 2 to 3 hours to complete the slaughter operation, care should be taken to avoid long exposure of the carcass to high temperatures. During cold weather of less than 30° F, the animal can be slaughtered at any time, because spoilage bacteria do not grow rapidly at cold temperatures. During periods of extremely cold weather, avoid letting the carcass freeze immediately after slaughter because the meat will be less tender than if it is permitted to chill without freezing. Slaughter during high winds may result in dirt and other contaminants being blown onto the carcass. Waste Disposal All waste products should be disposed of in a sanitary manner. If the animal is to be slaughtered in the open, select a site with good drainage so that blood and water can drain away from the carcass. Do not allow blood and water to pollute nearby streams or other water supplies. Disposal of viscera and hair is often a problem. Arrange to have a local processor or rendering plant pick up these wastes. If this is not possible, bury them so that dogs and other animals cannot dig them up. Hair can be burned. Slaughter Equipment Elaborate and expensive equipment is not necessary but certain items are essential (fig. 1). The amount of equipment will depend on the slaughter procedure used. If the carcass is to be scalded rather than skinned, additional equipment will be needed (items 16 to 23). The following slaughter equipment is recommended: 1. .22 caliber rifle with long or long rifle cartridges 2. Sharp skinning knife and steel 3. Boning knife 4. Block and tackle or chain hoist—should be strong enough to hold weight of pig to be slaughtered 5. Chocks—concrete blocks work well 6. Meat saw 7. Oil or water stone 8. Ample cold water for washing hands, equipment, carcass and byproducts 9. Tree with strong limb, beam or tripod 8 to 10 feet high, or tractor with hydraulic lift 10. Spreader (gambrel or metal pipe) 11. Buckets (2 or 3) 12. Ice or cold water 13. Straw for placing under animal during evisceration and splitting 14. Clean cloths or plastic for protection of meat during transport 15. Clean string 16. Scalding barrel 17. Pot or barrel for heating water 18. Bell scrapers (1 or 2)—these are not necessary but helpful 19. Plywood or other solid material for scalding platform 20. Thermometer which registers up to 200° F 21. Dry wood for fire 22. Hog or hay hook 23. Propane torch or blow torch [Illustration: Slaughter equipment displayed] Figure 1.—Equipment for slaughter. Be sure that all equipment that will come in contact with meat is thoroughly cleaned. Blood and other materials that get on the outer garments of workers during slaughter should not be transferred to the carcass after it is washed. Additional equipment needed for cutting the carcass is listed in the section, “Cutting.” SLAUGHTER Stunning The animal should be killed as quickly and humanely as possible. In most slaughter plants, hogs are immobilized either by electrical stunning or carbon dioxide gas suffocation. On the farm a hog can be stunned by striking it one sharp blow with a mechanical stunner or by shooting it in the forehead midway between and slightly above the eyes. The first attempt should be successful (fig. 2). Improperly placed bullets could cause the animal much pain and injure helpers or other livestock. Animals that become excited during stunning will not bleed as well as those less excited. _As always the case whenever using firearms, exercise all appropriate safety precautions_. [Illustration: Rifle muzzle pointed at forehead of hog] Figure 2.—Stunning. Bleeding Bleeding is a very important part of the slaughtering operation. The animal should be bled within 2 minutes after it is down because the blood pressure may increase and thus break the capillaries and cause an unattractive condition in the meat called “blood splash.” Although meat with this condition is safe for consumption, it is quite unpleasant in appearance. After stunning the animal, place it on its back, perfectly straight with the head close to the ground. A helper can stand over the animal and hold its front legs. Locate the tip of the breastbone, along the midline (fig. 3). A 6-inch sticking knife sharpened on both sides of the tip is best. However, a regular boning or skinning knife can be used. Hold the knife at a 35 to 40-degree angle, thrust it under the breastbone with the point aimed toward the tail and then give an upward thrust (dip the point) to sever the carotid artery (figs. 4 & 5). No twisting or cross-cutting of the knife is necessary. If the hog does not bleed, insert the knife a little deeper a second time and there should be little difficulty getting a good stick. To avoid a “shoulder stick” do not insert the knife too far to either side. The bloody tissue resulting from a shoulder stick will subsequently require trimming. Care should also be taken to make certain that the hog does not kick you or the knife. [Illustration: Man placing finger on tip of breastbone] Figure 3.—Locating breastbone. [Illustration: Side view drawing of supine hog with knife inserted] Figure 4.—Sticking (bleeding). [Illustration: Photo showing positions of workers during sticking] Figure 5.—Positions for sticking. Hair or Skin Removal Once the animal is bled, the hair can be removed by scalding the animal in hot water and scraping; or the skin and hair can be removed by skinning. Traditionally, hogs have been scalded and scraped, and the skin is left intact. Both procedures will be discussed because many people now find the skinning method to be easier, to require less equipment, and to result in an equally acceptable final product. _Scalding and Scraping Method:_ For scalding, the most important consideration is maintaining an adequate supply of properly heated water. Approximately 50 gallons of near boiling water will be needed for each pig. This water should be ready (boiling) before the animal is stunned and bled. After the hot water is placed in the scalding barrel, it can be adjusted to the proper temperature for scalding by adding cold water. The animal can be scalded by several methods. The easiest method is to have two barrels, one for heating the water and one for use as a scalding vat. Fifty-five gallon barrels will be large enough for most hogs. The scalding barrel can be buried in the ground at a slight angle; thus movement of the hog in and out of the barrel is easier (fig. 6). Be sure the angle of the barrel is not too flat or the barrel will not hold enough water to cover the carcass. Another method for scalding is to have a scalding vat or a barrel under which a fire can be built. This method requires more construction, and the temperature of the water is difficult to control. [Illustration: Partially buried barrel adjacent to a plywood board] Figure 6.—Scalding equipment. Slow scald is usually best. Scalding water temperatures between 140° and 145° F are optimal. At these optimal temperatures, 3 to 6 minutes of scalding are required to loosen the hair and scurf (layer of accumulated oil, dirt, and the outer layer of cells on the skin). In the fall when the winter hair is beginning to grow, the hair of most hogs is difficult to remove. Higher water temperatures (146° to 150° F) or longer submersion times are usually required for scalding during this “hard-hair” season. About ¼ cup of rosin, lime, or some other alkaline material added to the scald water to aid in scurf removal results in a whiter skin. On the farm, regulation of water temperature is difficult. Add boiling water to the scalding barrel, then add cool water to adjust to the proper temperature. Begin with the scalding water at 155° to 160° F because it cools rapidly. At these high temperatures, the carcass must be kept in motion and pulled from the barrel several times. This movement prevents overscalding. Overscalding causes the skin to contract around the base of the hair (“setting the hair”) and cooks the skin. If the carcass is overscalded, the hair is extremely difficult to remove. After the proper water temperature has been attained, place the pig in the barrel, head first (fig. 7). Rotate the carcass in the barrel, pulling it in and out of the water occasionally. Check the hair often for ease of removal. The hair slips first over the back and sides, then in the flank regions. When the hair can be pulled easily in the flank regions behind the shoulders, remove the hog from the barrel and place the rear of the hog in the water. [Illustration: Man holding hog in scaling barrel] Figure 7.—Scalding head first. While the rear of the hog is scalding, pull the toe nails and dew claws from the front feet by inserting a hook into the top of the nail and pulling (fig. 8). Scrape as much of the hair on the head as possible, especially around the ears and snout (fig. 9). When the hair slips in the rear flanks, remove the hog from the barrel. Remove the toe nails and dew claws from the rear legs and pull the hair from the tail. [Illustration: Hook removing toe nail] Figure 8.—Removing toe nails. [Illustration: Knife scraping cheek hairs] Figure 9.—Scraping head. Grip the legs with both hands and twist to pull off the hair. Remove the hair in the difficult areas (head, feet, jowl) first, then proceed to the easier areas (back, sides). If you use the bell scraper, tilt the scraper upward on the forward edge and pull the scraper forward, applying as much pressure as possible (fig. 10). [Illustration:Man scraping head of hog in scalding barrel] Figure 10.—Scraping head. Scrape the hot carcass as quickly as possible because the skin tends to “set” as it cools. If patches of hair and scurf are difficult to scrape, cover them with a burlap bag and pour hot water over them. Scraping is made easier by moving the legs or the head in order to stretch the skin, smoothing the wrinkles along the sides. After most of the hair has been removed, pour water over the carcass and continue scraping. Place the scraper flat against the skin and move it in a rotary manner (fig. 11). This procedure aids in removal of scurf and dirt as well as removal of the rest of the hair. If patches of hair cannot be removed with the scraper, use a knife. Some people prefer to use a knife for the entire operation. [Illustration: Man scrapping the side of a hog] Figure 11.—Scraping middle. The carcass is now ready to be suspended. Clean the feet by cutting away the soles of the feet and cutting between and around the toes (fig. 12). Expose the gambrel tendons by cutting through the skin on the backs of the rear legs from dew claws to hock (fig. 13). Cut down each side of the tendons, being careful not to cut the tendons (fig. 14). Insert the spreader or gambrel under both tendons on each leg. Secure the legs to the spreader bar and suspend the carcass (fig. 15). [Illustration: Man holding toes of hog’s feet] Figure 12.—Cleaning feet. [Illustration: Man running knife up back of hog’s hind leg] Figure 13.—Exposing gambrel tendons. [Illustration: Man hold hog leg with thumb between bone and tendon] Figure 14.—Exposing gambrel tendons. [Illustration: Hog suspended with legs tied to spreader] Figure 15.—Suspending the carcass. If available, a propane torch or blowtorch can be used to singe the remaining hair and scurf (fig. 16). Singeing removes most of the hair and allows small, light hairs to be seen. Use caution during singeing to prevent burning the skin. Shave the remaining hair and wash the carcass thoroughly. Continue with evisceration and splitting (pages 24–35). [Illustration: Man holding propane torch near hog’s ear] Figure 16.—Singeing. _Skinning Method:_ The skinning procedure used for pork carcass is similar to that used for beef carcasses. Skinning requires less equipment and can be done faster than scalding and scraping. We have commonly believed that the skin was needed on hams and bacon to assure proper curing; however,