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Sausage Safety - Curing & Cooking

Posted: Fri Jan 14, 2011 12:50
by Chuckwagon
Sausage Safety - Curing & Cooking

Rytek Kutas said the first rule of sausage making is, "If it can't be cured... it can't be smoked!" Casing the sausage cuts off oxygen. Anaerobic bacteria do not require oxygen and certain pathogenic bacteria in sausage being smoked certainly present a risk. Meat covered with plastic wrap for "overnight curing" inside a refrigerator presents a risk as well. Most bacteria thrive in the "danger zone" between 40° F. 4° C.) and 140° F. (60° C.). However, two foodborne bacteria, listeria monocytogenes and yersinia enterocolitica can actually grow at refrigerator temperatures!

Smoke also cuts off oxygen. True, the cooking will destroy trichinella spiralis - the parasitic roundworm whose larval form may be present in the flesh of pork or wild game - whose painful infection is known as trichinosis. Cooking will also destroy staphylococcus aureus, salmonella, campylobacter jejuni, shigella, bacillus cereus and other bad bugs, BUT... botulinum spores are another story! They are extremely persistent and will survive heating up to 250°F. (121°C), freezing, smoking, and drying.

An obligate anaerobe cannot grow in the presence of oxygen. Without oxygen, the addition of sodium nitrates or sodium nitrites is necessary to prevent botulism poisoning. It also becomes crucial that meat be removed from the "danger zone" temperature range as quickly as possible during any preparation or cooking process. This includes grinding, mixing, and stuffing sausages, procedures often supported using ice, ice water, or refrigeration and freezing. As bacteria need moisture to multiply and meat is about three-quarters water, it becomes an ideal environment for the growth of bacteria, even when it is mostly dried.

Clostridium Botulinum is a common obligate anaerobic bacterium microorganism found in soil and sea sediments. Although it can only reproduce in an oxygen-free environment, when it does reproduce, it produces the deadliest poison known to man - botulinum toxin. One millionth of a gram ingested means certain death - about 500,000 times more toxic than cyanide. Onset of symptoms can occur quickly and include nausea, stomach pain, double vision, and spreading paralysis, ultimately reaching the heart or respiratory organs. If treatment is given and the dose is low, half of those affected may survive, but recovery may take months or years. Although fatalities occur yearly, especially in countries where home canning is popular, the risk of acquiring botulism is very, very low. However, the lethal consequences of poisoning may make you wish to reconsider the proper addition of sodium nitrate/nitrite in your products to almost eliminate the risk. Worldwide, there are about 1000 cases of botulism each year.

The rod-shaped bacterium was first recognized and isolated in 1896 following the poisoning of several people who had consumed bad ham. It was later discovered that due to the enzyme superoxide dismutase, the bacterium might actually tolerate very small traces of oxygen. Once again, botulinum spores are extremely persistent and will survive heating up to 250°F. (121°C), freezing, smoking, and drying. Insidiously, they lie in wait for the right conditions to occur and give no foul smell or taste, making it even more treacherous. In non-cooked fermented sausages, the microorganism must be destroyed using a combination of salt, a drop beyond 5.0 pH, and a minimum drop in Aw water activity to 0.97 or less.

Additionally, placing fresh vegetables or un-sterilized (garden fresh) spices into sausage is not recommended as botulinum spores are not uncommon on leafy herbs, peppers, beans, chilies, and corn. Cut off from oxygen by being stuffed into casings and placed in a smoker, the smoking temperatures are ideal for botulinal bacteria growth. The risk using fresh garlic is less, but cases of botulism poisoning have been reported after people have eaten home-canned garlic cloves in oil - the ideal environment for anaerobic bacterial growth!

Be safe sausage grinders! And...
Best wishes, Chuckwagon

[USA] Cure question

Posted: Thu Mar 31, 2011 02:57
by Gray Goat
I understand the need for adding cure to slow cooked or smoked sausages and meats but why is it ok to not have cure on BBQ. If I run in to a stubborn pig or cow I will have butts and briskets on my offset for upwards of twelve hrs. Does it have to do with the higher finishing cook temps?

Posted: Thu Mar 31, 2011 05:24
by Chuckwagon
Gray Goat:
Are you still wiping your hands on your beard?
You are correct. In short, the answer is "higher cooking temperatures". Even if some bacteria multiply initially under the conditions of long cooking periods, most are likely to be destroyed as cooking temperatures surpass 150°; F. (66°;C.). The USDA /FSIS (Food Safety Inspection Service) recommends that all meats be cooked to at least 160°; F. This really raises particularly painful perplexity because most wranglers I know, prefer their beefsteak cooked medium-rare... and that`s only 130°; F. (54°;C.). Shucks pard, I used to eat a steer just because it strayed too close to the campfire!

Consider the cooking temperature of your offset smoker. The chamber is probably 200 - 225°;F. (93- 107°;C.). Roasted BBQ`ed pork, falling off the bone, has been cooked to about 190°;F. (This is BBQ`ing not grilling). Now consider, the temperature at which the parasite trichinella spirallis is destroyed ... 138°;F. (59°;C.). Then at about 150°;F. (66°;C.) or thereabouts, a host of bacterial bad guys are destroyed, including listeria monocytogenes, cyclospora cayetanensis, campylobacter jejuni, escherichia coli 0157:H7, (e-coli), salmonella, staphylococcus aureus and clostridium perfringens as well as others.
Because cased, smoked-cooked, and air-dried sausages are all prepared below 150°;F. or even not cooked at all (dry-cured), they MUST be treated with sodium nitrate/nitrite cures as there simply is not enough heat present to destroy bacteria and other microorganisms.
The most commonly recognized foodborne infections are those caused by the bacteria species campylobacter, salmonella, and E.coli, along with a group of viruses called calicivirus also known as the Norwalk and Norwalk-like viruses. Campylobacter remains the most common bacterial cause of diarrheal illness in the world and incredibly, most raw poultry meat has campylobacter on it. Salmonella is also a bacterium widespread in the intestines of birds, reptiles, and mammals. Its infection, known as samonellosis, typically includes fever, diarrhea, and abdominal cramps. E.coli 0157:H7 is a bacterial pathogen infecting cattle and other similar animals. Human illness typically follows consumption of food or water that has been contaminated with microscopic amounts of animal feces.

Again, our first line of defense is the application of extreme temperatures applied to meat either being cooked or frozen. As sausage is prepared, it is essential to work with only small batches at a time outside the refrigerator. Very often, meat is partially frozen before it is put through a grinder and bacteria at this temperature remain mostly inactive. In the grinder, ice chips are sometimes added to keep the temperature down as the friction of grinding actually warms the meat. Out of the refrigerator, most bacteria begin to wake up as the temperature rises above 40°F. (4.4°C.). At 50°F. (10°C.), it is safe to work with the meat only temporarily before it goes back into the refrigerator. At this point, salt in the amount of 2.5% - 3% is frequently added to partially restrict pathogenic and spoilage bacteria growth, as beneficial bacteria go to work producing protective acidity within time. Most bacteria thrive at the temperature of our bodies (98.6°F. / 36.6°C.). As temperatures rise much above the "danger zone", their growth becomes restricted until around 140°F. (60°C.), they begin to die. Yet, strains such as Clostridium botulinum, may survive heating up to 250°F. (121°C) by producing heat-resistant, isolating envelopes called spores - nature`s way of protecting the organism by sheltering the bacteria from other unsympathetic environmental conditions.
Most bacterial microbes need to multiply before enough are present in food to cause disease. The way food is handled after it is contaminated can also make a difference in whether or not an outbreak occurs. Given warm moist conditions and an ample supply of nutrients, merely one reproducing bacterium dividing itself every half hour can produce 17 million progeny in only 12 hours! As a result, lightly contaminated food left out overnight can be highly infectious by the next day. If the food were refrigerated promptly, the bacteria would not multiply at all. In general, freezing prevents nearly all bacteria from growing but merely preserves them in a state of "suspended animation". However, this general rule has a few surprising exceptions. Two foodborne bacteria, listeria monocytogenes and yersinia enterocolitica can actually grow at refrigerator temperatures!

Best Wishes,