Food safety is something that every person who plans to store their own food should learn about first. Not just the techniques to ensure that your food is safe, but also the signs that there may be a problem, as well as the different food borne illnesses and their symptoms. Food borne illnesses are not as uncommon as you might think, and while chances are good that you will never have a problem with the food you preserve, part of the reason that will be so, is the precautions that you will take when canning your food.
Food Safety starts at the Beginning
Food safety and avoiding bacteria starts with cleanliness and fresh food. Everything you use, including your hands should always be washed thoroughly, and produce should be washed and at the peak of ripeness without any spoilage. Sterilizing work surfaces with water and bleach and sterilizing jars and equipment can help to prevent any possibility of bacteria getting into your jars.
The Difference between Water Bath and Pressure Canning
Water bath canning is the method used for high acid foods. When water simmers in a water bath canner it reaches a temperature of 180 degrees, this is sufficient to kill off most bacteria. At a full boil the temperature reaches 212 F that is hot enough to kill off yeasts, molds, and bacteria, but will not kill off spores. High acid foods or those that have a high acid content due to the ingredients added have no more than a 4.5 on the ph scale. This high acid content is enough to keep bacteria and fungus spores from hatching and multiplying to levels that can make you sick. The long and short of this, is that hot, boiling water is enough to kill off active bacteria and the high acid content is enough to prevent further growth of bacteria, making it only safe to preserve high acid foods in a water bath. This includes anything that has been made more acidic, such as adding lemon juice to tomatoes or pickling. The high acid content of the lemon juice and vinegar is enough to keep the food safe with just water bath canning.
Pressure canning is used for low acid foods that cannot inhibit the growth of deadly spores. Pressure canning in an approved pressure canner can bring temperatures up to 250 degrees which is sufficient enough to kill all any food borne bacteria or spore.
Keep in mind that it is important to follow all directions when canning. The safe temperatures must be reached all the way to the middle of the foods being preserved. This means making sure that you maintain that temperature for a specific amount of time. This time will vary depending on the density of the food and the altitude in your area. Altitude can also affect the pounds of pressure you must use to achieve the right temperature. You should also read carefully the types of foods it is safe to can, as well as how dense the food in your jar can be.
Food Borne Illnesses
Most food borne illnesses can make you really sick but will not threaten your life. Many of them are obvious enough that for the watchful person they are easy to identify. It is important to understand however that not all food borne illnesses are this way. Botulism can develop in a jar of food undetected it has no smell and is not apparent. It is also a very serious illness that can kill.
Understanding the different types of illnesses and their signs can give you a second level of protection that can help to ensure that your family stays safe. There are many different types of bacteria, most of those bacteria like salmonella cannot survive heat, and so properly processing should make these illness not a concern. It is also important to keep a close eye on how and where you store your jars, as well as checking seals on the jars to ensure bacteria cannot grow in your food.
Salmonella – Salmonella and other similar bacteria usually cause flu like symptoms that while extremely unpleasant are not life threatening for healthy individuals. Salmonella most frequently comes from meats, but can also be on contaminated fruits and vegetables. The bacteria is easy to kill however with proper heating to the appropriate temperatures.
Clostridium Botulism – Botulism is a serious food borne illness and is one of the most common illnesses found in home canning. There is no smell or sign that botulism is present in food, and only proper canning procedures and cooking can ensure that there is no botulism in your food. Botulism incubates at a wide range of temperatures, but cannot develop if refrigerated below 40 degrees or above 140 degrees. This is why most experts will suggest that you refrigerate any jars that do not seal properly, or that you are uncertain about, and that when you open low acid food jars that you cook it at a full boil for 10 minutes. This 10 minute full boil will kill any botulism that might happen to be present. Botulism is very rare, less than 100 cases of botulism due to home canning are reported every year. Of those 20 percent are fatal. But even with figures like that it is important to ensure that you do everything you can to avoid it.
What about E.Coli and Listeria? – With these two food borne disease in the news a lot of people want to know whether they are a problem for home canning. Both of these bacteria’s much like most of the food borne bacteria can be killed with cooking. They are typically only a problem in unpasteurized or raw foods, so they are not an issue when it comes to canning provided you process foods according to the guidelines.
Keep in mind that bacteria that exists in your kitchen can come in contact with a jar, lid, or even food in the refrigerator, and bacteria once present if not killed can quickly grow making you or your family sick. This is why it is so important to make sure that you follow all the procedures and make sure that your work area is clean and sterilized. Jars should be sterilized as well and lids and rings should be kept in a pot of boiling water until used. Jars should be stored in a cool dry place, and rings should be removed. This makes it easier to see if there is bacteria present.
Keep in mind, forgetting to sterilize a jar or lid, is all that it takes to introduce bacteria to your canning. For this reason you should also always be on the watch of potential spoilage even for high acid foods. Foul smells, mold, bubbling inside the jar, or a lid that bulge are all signs that bacteria may have reached your food. Low acid foods should always be cooked prior to serving, 10 minutes at a full boil will ensure that any bacteria including botulism is killed.