Mastering the Craft of Making Sausage (9 page)

• Most sausage is cooked until it is safe to eat, but just barely safe.

Reading this chapter will not qualify a person to become a public health specialist, and it does not cover all the health hazards related to food, but it will provide the basic information that a sausage maker needs know.

Some of the following information may cause concern because it deals with potential health problems related to food. I hope that it will be reassuring for me to mention that in all of the years that I have made sausage and smoked food, not once has the product spoiled during processing, and not once has a product caused food poisoning or any other health-related problem. If safe food-handling guidelines are practiced, sausage making poses no more of a health risk than common cooking.

Trichinosis

The parasitic disease known as trichinosis is most often associated with eating undercooked pork. A little less than 1 percent of hogs in the United States are infected, and one of the main causes of the disease is that pigs are sometimes fed uncooked garbage containing raw pork scraps. Well-informed hunters usually know that bear meat can also harbor these nasty little larvae. Trichinae may be present in the meat of any warm-blooded omnivorous animal, and they exist even in the meat of some carnivorous animals and warm-blooded marine animals such as the seal.

The larvae in consumed meat will mature into adult roundworms in the small intestine of the host animal—or human host. Some of the females will bore a hole in the small intestine of the host and deposit eggs. The resulting larvae enter the bloodstream and burrow into the tissue of various voluntary muscles. The host, as a defense mechanism, forms a coating around each larva. This coating, with the roundworm larva inside, is known as a cyst. In time, the cysts usually become calcified on the outside. The larvae, inside the cysts, remain in the muscles in a dormant condition. If the raw or undercooked flesh of this animal is eaten, the cycle repeats itself.

The cysts, each containing a coiled larva, are about
¹
⁄50 inch (0.51 mm) long. That is about half the length of the comma in this sentence, more or less. Therefore, they are essentially invisible to the naked eye. The U. S. INSPECTED AND PASSED stamp means nothing as far as trichinosis is concerned: The inspection does not include microscopic inspection of the flesh of each hog. Furthermore, even if the flesh of each animal were to be inspected by microscope, cysts may be overlooked.

A drug has been developed to treat trichinosis, but it is much better to avoid contracting the disease in the first place. Intestinal disorders followed by chronic muscular pain are two of the many possible symptoms. This is the bad news. The good news is that it is very easy to kill trichinae before they cause problems. There is no danger in eating pork that has been treated by cooking it properly or by freezing it according to USDA (United States Department of Agriculture) instructions that are described below.

The common way to protect positively against trichinosis is to heat all meat (from susceptible animals) to a
minimum
internal temperature of 137° F (58.4° C)
throughout.
To be even safer, commercially produced “fully cooked” meats, such as hams and sausages, are usually heated to a minimum internal temperature of between 152° and 154° F (between 67° and 68° C). When we cook pork in the oven or in a frying pan, the internal temperature usually climbs even higher than this.

Another way to kill trichinae in pork is to freeze it according to USDA regulations. Any one of the following USDA approved freezing procedures will definitely kill all the trichinae in pork:

• -20° F (-28.9° C) for 12 days

• -10° F (-23.4° C) for 20 days

• 5° F (-15° C) for 30 days

You may freeze the pork in your home freezer if your freezer temperature is cold enough, but most home freezers will not get that cold. Another consideration is that there are specifications on the thickness and stacking of the meat. Finally, if it is done according to USDA regulations, the temperature of the freezer must be accurately measured and monitored.

It is easier and safer to ask your butcher if he or she can order some
Certified Pork.
Certified Pork has been frozen according to the USDA regulations, and it will not cause trichinosis even if it is eaten raw.

Chain grocery stores may not be able to provide you with Certified Pork unless it is on the list of items for which the butchers can make a special order. However, local meat distributors or meat packers might be able to supply it, especially if they supply local sausage makers. An independently owned grocery store or butcher shop is another possible source. The most commonly available cut of Certified Pork is pork shoulder (Boston butt), and it is usually sold by the carton; one carton contains several frozen shoulders. Be sure that it has some kind of tag, label, or stamp that reads CERTIFIED PORK.

There is only one case where Certified Pork, or the equivalent,
must
be used: when the finished, ready-to-eat product contains uncooked pork. Examples of this are some varieties of fermented sausages. For all other products, use a meat thermometer to make sure that the pork is fully cooked.

Note that in the above discussions of freezing meat to kill trichinae, I used the word
pork.
Strains of trichinae found in some wild animals (especially those that live in cold or arctic climates) may be more resistant to freezing temperatures than the strains found in the domesticated swine. It is risky, therefore, to use the USDA freezing method to kill trichinae in the meat of susceptible
wild
animals such as bear. Kill the trichinae by making sure that the meat is heated to
at least 137° F (58.4° C) throughout.
Better yet—heat it to 160° F (71.1° C).

If you intend to process bear meat, you may be interested in the results of a study by a Montana State University researcher. The study was conducted from 1984 through 1989, and it consisted of inspecting the meat from 275 bears.
Bears infested with trichinae accounted for 15.6 percent of the total inspected.
In another study, this time by the University of Washington, it was reported that trichinae in bear meat might survive the USDA freezing regulations applied to pork. Be safe:
Cook
meat from potentially infested wild animals; don’t depend on freezing to kill those insidious roundworm larvae.

You should never put raw or undercooked meat from susceptible animals in your mouth, even though you intend to just taste it and spit it out. Furthermore, always wash the cutting board and knives with hot water and dish detergent if they have been exposed to such meat.

Tularemia

Tularemia (also known as rabbit fever) is a disease of rodents. It is caused by a bacterium that can be transmitted to other animals and humans. If humans contract this disease, it is most often due to handling infected animals or eating the undercooked flesh of infected animals. Tick bites, or bites from bloodsucking flies, can also cause tularemia infection.

This disease can bring on a high fever, chills, headaches, vomiting, swollen lymph nodes, and various skin problems. Fortunately, it is not a fatal disease, and antibiotics will bring about dramatic recovery.

Wild rabbits are the greatest source of tularemia infection for a person who hunts wild game. If you handle wild rabbits, be sure to wear rubber or plastic gloves with no holes in them; it is believed that these bacteria can penetrate even healthy and uncut human skin.

It is perfectly safe to use wild rabbit to make sausage, but it must be cooked as well as pork: 160° F (71° C).

Food Poisoning

SALMONELLA

Salmonella food poisoning is common. (It is sometimes mistakenly called ptomaine poisoning.) The United States Public Health Service estimates that there are as many as 2,000,000 cases of salmonella food poisoning every year in the United States, and the incidence of this kind of poisoning is increasing. It is rarely fatal, but it can cause death in infants, older people, and people who are in poor health. With a little care by those who handle, prepare, and process food, there is little need to fear this disease.

Salmonella has no connection with salmon. The physician who did most of the initial research on these bacteria was named Dr. Daniel E. Salmon, and the bacteria were named in his honor. There are about 400 kinds of bacteria in the salmonella family, and several of them cause the common salmonella food poisoning.

These salmonella bacteria cause gastrointestinal infection. The symptoms may range from mild intestinal cramps to very severe diarrhea. Symptoms usually begin 6 to 48 hours after eating the contaminated food, and they persist for 4 to 16 hours. The right type of antibiotic for this bacterial infection can provide a very effective cure.

The salmonella organisms that cause food poisoning most often occur in eggs (especially in eggs that have a crack in their shell). It also occurs in poultry, meat, and in other kinds of animal products such as whipped cream, as well as in contaminated water. The bacteria cannot be detected by odor, and they can survive in frozen and dried foods. If salmonella bacteria are present, they will multiply at temperatures between 40° F (4.4° C) and 140° F (60° C). Temperatures that approximate the temperature of the human body are most favorable for their proliferation.

Salt and sugar help to prevent the growth of salmonella and other microorganisms. Salt inhibits spoilage and the proliferation of pathogens by reducing the amount of water available for microbial growth. Sugar inhibits spoilage and the proliferation of pathogens by creating an unfavorable environment. Consequently, if a product is smoked at temperatures between 40° and 140° F (4.4° and 60° C), it should contain a substantial amount of salt and sugar, and it should not be smoked with humid air. Do not smoke sausage or other foods in a water smoker below 140° F (60° C).

To prevent salmonella poisoning:

• Keep all utensils clean, especially the cutting boards. Be sure to wash them after they are exposed to raw meat.

• Avoid cracked eggs, unless they will be heated to an internal temperature of 165° F (74° C).

• Store food at 40° F (4° C) or below.

• Thaw meat in a refrigerator, or use the cold water thawing method. Microwave thawing is safe, but it is not recommended for the thawing of meat that will be used to make sausage.

• Do not let raw meat touch other foods.

• Keep hot foods hot.

• Refrigerate or discard leftovers immediately.

Following these simple precautions from the first stage of processing to the point of consumption will greatly reduce the risk of salmonella poisoning and poisoning from other varieties of bacteria. To reduce the risk to zero is impossible, even if you become a strict vegetarian.

The following are other bacteria that cause food poisoning: staphylococcus aureus, campylobacter, listeria monocytogenes, clostridium perfringens, clostridium botulinum, and Escherichia coli O157. A few of these bacteria can also form toxins if the food is stored between 40° F (4° C) and 130° F (54° C) for an extended time, and these toxins cannot be destroyed by normal cooking. Consequently, proper storage not only helps to prevent spoilage, it helps to prevent food poising from pathogens and the toxins that some of them produce.

Clostridium botulinum and E. coli O157 require additional explanation.

BOTULISM

Botulism
is a word that was coined by Dr. Emile van Ermengem in 1896 when she was investigating the cause of food poisoning related to the eating of German sausages.
Botulus
means sausage in Latin.

Botulism is an often-fatal form of food poisoning caused by clostridium botulinum. Eating improperly canned foods is the common cause. Another cause is eating preserved foods that have been improperly processed and packed in an airtight plastic package or in an airtight casing. Commercially prepared foods rarely cause botulism because of the precautions taken by commercial processors. Foods improperly processed at home, particularly home-canned foods, are the main culprits.

No food-processing procedures in this book will lead to the formation of botulin, the toxin that causes botulism. However, the processing of smoked sausage could result in botulism if the specified nitrite curing powder is not used.

Clostridium botulinum
spores are everywhere. They are in the soil, on fruit and vegetables, and on meat and fish. Consequently, they are also found in the human intestines. The spores themselves are harmless; the poison, called
botulin
, is created only when the spores reproduce. In order for the spores to multiply, several conditions must exist
at the same time
: an airtight environment, a certain temperature range, a favorable chemical environment (non-acidic, for example), and a period of storage favorable for reproduction. The processed food will be free of the toxin if
any one
of these required conditions is eliminated.

None of the processes mentioned in this book specify packing the food in a perfectly airtight container, such as a can or a sealed canning jar. Tightly sealed plastic bags or vacuum packs are suggested for use while cooking, refrigerating, or freezing the product; nevertheless, they are never suggested for storing or processing foods under conditions that might cause spores to reproduce. However, sausage casing that is packed tightly and sealed tightly can approximate an airtight container, so caution is prudent for sausages that will be smoked. The smoking temperature and lengthy smoking time could encourage spore reproduction.

Fortunately, there is a very easy way to make the smoked sausage perfectly safe: Change the chemical composition of the sausage in a way that will positively prevent toxin formation.