from FSIS Appendix A.
Temperature control
An important factor in controlling the growth of bacteria is proper temperature control. Did your parents ever yell at you to shut the fridge door? My folks did. Probably more so because it caused the fridge to run and use up electricity. But the reality is that spoilage of food happens more quickly at warmer temperatures. That’s because bacteria like to grow when the conditions are warmer.
When processing meat, you want to keep your proteins as cold as possible throughout the process. This will result in a higher-quality product, as well as a safer product. When you are storing meat for processing, you want to store it as close to the freezing point as possible without freezing it. When processing, you want to keep your meat mixtures cold, but this can be difficult when cutting, grinding, stuffing, and so on because of the time the meat is out of refrigeration, coupled with the added friction that comes with grinding and stuffing.
Several years ago, Dr. Bruce Tompkin presented the results of a study, titled “The significance of time-temperature to growth of foodborne pathogens during refrigeration at 40–50°F.” These results showed that you can safely process pork, chicken, and beef at temperatures above 60 degrees Fahrenheit and still be safe. However, it isn’t ideal for producing a quality product. So, to be safe and to ensure the best results, you should use a digital temperature probe such as the one shown in Figure 2-5.
Photo by David Pluimer
FIGURE 2-5: Temperature probe.
Pathogens of Concern
Food poisoning is nasty and can be scary. The best way to have confidence in the work you are doing is to know the risks, call them by name, and understand the best way to manage the risks. There are a handful of bacteria that can be present in different types of proteins, and there are a handful of ways to mitigate the risk of these bacteria. In the case of raw sausages that require a cook step prior to consumption, cooking will be your final line of defense. A good understanding of each pathogen of concern and its respective Achilles heal will help build confidence in your processes and ultimately help you stay safe!
Salmonella
Salmonella is probably the most commonly known bacteria simply because of its prevalence in undercooked chicken. This is why even to this day, a well-cooked piece of chicken is heated to 160 degrees Fahrenheit. This can give it the consistency of rubber if done too well, but, hey, better safe than sorry. Salmonella is a concern in poultry and to a lesser extent in pork. Salmonella can be controlled by lowering the meat’s pH (acidifying). Cooking to 160 degrees Fahrenheit will also kill it.
Staphylococcus
Staphylococcus, or Staph, may exist on the surface of some meat and poultry, but it is largely introduced into food through human contact. It can be controlled through acidification. A cooking step will also kill it. Your best tools in combatting it are proper hygiene, and cleaning and sanitation of your work area before, during, and after food contact.
Campylobacter
Campylobacter is found in both poultry and pork, though less commonly in the latter. It is controlled by temperature, drying, and acidification.
Listeria monocytogenes
Listeria monocytogenes is commonly found in ready-to-eat food products. It can make healthy people feel like they have the flu, but it can also cause meningitis or even be terminal in elderly people, infants, and pregnant women. This particular bacteria is pretty tough to beat. Your best bet at home is to be thorough with your sanitation.
Clostridium botulinum and C. perfringens
I learned about botulism at a very young age, grocery shopping with my father. It almost became a game where I would look for the cans that had swollen tops. Those were the ones that you knew were bad. I would then turn them in to the customer service desk and feel like a super hero. Botulism is a pretty serious disease caused by the C. botulinum toxin. This toxin thrives in low- to no-oxygen environments (think vacuum bags, smokers, and the inside of a sausage). You can control it with sodium nitrite and acidification (by lowering the pH).
Escherichi coli O157:H7
There are numerous types of Escherichi coli (E. coli) in the world. The big, bad one that causes recalls of food 100 percent of the time is a specific strain of E. coli referred to as O157:H7. This is the stuff that will cause serious illness and potentially death if not treated immediately. E. coli is generally an issue only for beef. Cows, when processed under USDA inspection, undergo prevention measures for O157 to ensure it is not spread if it is present. That said, if you decide to work with beef to make a sausage or an air-dried beef product like bresaola, you may want to take a preventative measure of your own to further ensure you don’t spread it.
1 Pour 6 ounces of distilled vinegar of 5 percent strength into a spray bottle.
2 Pour 4 ounces of distilled water into the spray bottle.
3 Shake to mix.
Lightly mist your beef with the spray and let it rest in the fridge overnight before you continue.
Trichinella
This isn’t a bacteria but it’s gross nonetheless. Trichinella is a small roundworm that is fairly common. Many controls have been put in place on the farming and processing side to reduce the presence of Trichinella in pork, almost to the point of eradication. However, it is still worth getting familiar with this problem, especially if you work with wild game. Trichinella can be controlled by deep freezing your protein first, which requires a long period of time at a deep-freeze temperature. You can also control it by drying.
There is a lot of information to be found through online research on how to manage and control the spread of Trichinosis. The USDA provides some very helpful guidelines that can be viewed online here:
