b. The Smoking Process. Smoke is produced by the combustion of slow
burning material, principally hardwood sawdust, which will produce a considerable
volume of smoke and combustion products that impart the desirable color and flavor to
the meat. Softwood sawdust contains resins and materials that impart undesirable
flavors. Sawdust is burned by means of an automatic stoker and the resulting smoke is
driven into the smokehouse by means of a fan. The amount of smoke produced can be
controlled by the speed of the stoker and the fan.
c. Heat. Heat is applied in the smoking process to remove excess moisture,
facilitate handling, promote absorption of combustion products, and inhibit bacterial
growth on the surface of the meat. Burning sawdust produces very little heat; therefore,
heat must be provided by steam coils or hot air ducts. There is no definite standard
time or temperature for smoking meat. Commercial smoke means almost anything from
6 to 36 hours of smoking at temperatures from 100 to 160F. Time and temperature
requirements for military procurement are stated in contractual documents.
a. Characteristic Aroma and Souring. Fresh, cured, and smoked meats, if
sound and wholesome, have a distinct and characteristic aroma. Any variation from the
characteristic aroma is indicative of deteriorative changes in the physical and chemical
makeup of the meat. Such changes are due to enzymatic action and the growth of
microorganisms that split protein substances and produce end-products whose odors
differ from those of wholesome meat. Souring can occur in all phases and degrees of
meat degeneration, particularly that which develops within the meat as distinct from
(1) Source of souring. The source of the microorganisms producing meat
souring has long been a subject for controversy and debate. For a considerable time, it
was thought that they were introduced into the meat through the medium of unsterile
equipment, such as thermometers, pumping needles, meat hooks, unclean benches,
vats, tierces, workers' hands and clothing, or unsterile pickle and curing agents. It is
beyond controversy that surface contamination of meats is productive of surface
spoilage.
(2) Temperature requirements. However, it is now the general opinion that
some of the microorganisms that produce spoilage are in the meat at the time of
slaughter. Souring is in an inverse ratio to the rapidity and completeness with which the
microorganisms are brought under control. Rapid chilling of cuts, reduction of
temperatures throughout the meat to 35F within a short period of time, and the
maintenance of proper temperature throughout the curing process are the best
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