Methods of curing
Curing ingredients are applied in dry form or as a solution of curing ingredients in water (pickle or brine). The combination cure is applied in the industry to take advantage on the complementarity of certain dry methods and pickle curing.
Dry curing: Dry salting is primarily used for the manufacture of salted pork from jowls, fat backs, clear plates or very heavy bellies. About 10 kg of salt and 62.5g of nitrite or nitrate is used to cure 100 kg of meat. Initially half of the cure mixture is rubbed over the cut, then remaining ¼ of the cure is overhauled after 1 week, finally rest of ¼ of the cure is overhauled after 3 weeks and then cured for 5 weeks. The cuts have to be turned periodically.
Dry sugar curing: It is applied mainly for hams, picnic shoulders and bellies. A 3.80 kg of salt, 2.30 kg of sugar, 143 g of nitrite is used to cure 100 kg of meat (62.5g of mixture per kg of meat). Half of the cure mixture is initially rubbed over the cut, then remaining ¼ of the cure is overhauled after 1 week, finally rest of ¼ of the cure is overhauled after 2 weeks. The curing has to be carried out for 7 days for each 2.5cm maximum cut thickness. A 6.3kg ham that measures 10 to 15 cm thick dimension requires 28 to 40 days of curing period.
Curing with pickle: Meat cuts intended for curing is dipped in the pickle until cure mix penetrate in the submerged cuts properly. The salt content in a pickle solution is measured with a salinometer, which indicates the specific gravity of the solution. Normally used pickles range from 40 to 100 degrees depending upon the desired saltiness of the final product and the method of curing.
Cover pickle curing: Used mainly for hams, picnic shoulders and bellies. For farm curing and dry storage without refrigeration, prepare a pickle of 75-85 degrees. Place the cuts in a vat, bin or barrel and pour enough solution over the cuts to completely cover them. Place a weight on the uppermost cuts and cure for 9 days per 2.5cm of maximum thickness. For mild curing and subsequent storage under refrigeration, a pickle of 45 degrees and curing for 11-12 days per 2.5 cm of maximum thickness is required.
Stitch pumping: Primarily used for hams and picnic shoulders. In this method, pickle is directly injected into the flesh by artery pumping and single needle or multi- needle stitch pumping to speed up the process and add bulk. A pickle of 75-85 degrees is suitable for farm curing and dry storage without refrigeration. Artery or stitch pumps enough pickle to increase the weight of the cut by 8 to 15 %. The meat is placed in a bin or barrel or on the shelves of a rack and cured for 7 days per 2.5cm of maximum cut thickness. For mild curing and subsequent storage under refrigeration, a pickle of 45 degrees and stitch pumping enough pickle to increase the weight of the cut by 8 to 15 percent and curing for 9 days per 2.5cm of maximum cut thickness is practiced.
Combination curing: Generally used for hams and picnic shoulders. This method shortens the curing time required and reduces the chance of spoilage because the cure process takes place inside and outside the ham. For farm curing and dry storage without refrigeration, a pickle of 75-85 degrees is preferred. Enough solution is artery or stitch pumped to increase the weight of the cut by 8 to 15 %. Meat is placed in a box, bin or barrel and enough curing solution is poured over the cuts to completely cover them. A weight is placed on the upper most cuts and cured for 3 to 5 days per 2.5 cm of maximum cut thickness.
Boneless middles or bellies (streaks) are used and curing operations are carried out at 3-5°C. Injection ratios vary between 10 to 20 % depending on whether immersion forms part of the curing. The final yield should not exceed 110 % of the original weight. Otherwise the bacon will be soft and wet and will not slice well. When immersion is used, the composition of the immersion brine approximates to that of the injection brine. Immersion periods vary between one day and four days. If not immersed, injected pork must be held for at least 12 hours before further processing. The approximate final composition of mild cured bacon should be: salt 2-4%, sodium nitrite approximately 100 mg/kg.
Curing is done at 3-5°C and curing gains vary between 15 to 25 %, the composition of the brine adjusted accordingly. After curing, meats should be cooked as soon as possible, certainly within 24 hours in the case of meat which has been mechanically treated. After cooking, the product is cooled rapidly. Composition of cooked ham should be: salt 2-4 %; sodium nitrite > 30 mg/kg.