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Thursday, February 06, 2014

Two Letters Re: The Joy of Canning



From the Survival Blog

I read with interest DDR's article “The Joy of Canning”. Most of her advice is spot-on and an excellent primer for new canners. I commend her for such a comprehensive article for novice canners. However, she includes some potentially dangerous advice that can invite the risk of botulism. For example, she correctly writes, "Vegetables and meats are considered low-acid and should always be processed in your pressure canner. This is also true of your soups, chilis, and most sauces. I find that it's a good idea, when in doubt, to pressure can just to be safe." Then, she contradicts this advice later in the article when she writes, "By the way, I water bath can my spaghetti sauce, even though it contains onions, peppers, and oil, because tomatoes are so very high in acid."This is INCORRECT. If her spaghetti sauce contains onions and bell peppers, then the food MUST be pressure canned in order to prevent the deadly disease of botulism. The acid in tomatoes does not negate the fact that onions and bell peppers are low-acid and must be pressure canned.

The rule of thumb for canning mixed-ingredient foods is to PROCESS THE FOOD IN ACCORDANCE WITH THE INGREDIENT REQUIRING THE LONGEST PROCESSING TIME. In this particular case, bell peppers canned in quarts require processing for 45 minutes at 10 lbs of pressure (adjusted for altitude). Pressure canning these low-acid ingredients for less time or water-bath canning them invites the risk of botulism.

Even without the addition of low-acid ingredients, sauces made with modern, hybrid tomatoes are often too low-acid to be safely canned in a water-bath. It is recommended that citric acid or another acidifier be added to increase the acidity in order to safely water-bath can. And as I mentioned, if there is anything else added to the sauce (such as bell peppers or onions), then the sauce MUST be processed in accordance with the ingredient requiring the longest processing time.

DDR also mentions canning butter or high-oil items, both of which are items that should not be canned at home. While DDR claims she's never poisoned anyone yet, I'd like to remind her that “past performance does not guarantee future results.” There are some things that home canners shouldn't can at home, even with a pressure canner, and even if those products are available commercially. Commercial canneries have additives, preservatives, and processing controls that are not available to home canners. They also have professional processing equipment that we can't duplicate at home.

The foods not recommended for home-canning include:

·        Foods packed in oil. Canning in oil is not recommended because oil coats and insulates botulism spores and creates an anaerobic micro-environment, which allows the spores to survive high heat. To kill botulism spores encased in oil would require pressure canning at such high temperatures and for so long that the food itself would be destroyed. (A small amount of oil, for example used in sautéing before canning, is acceptable.)

·        Highly viscous foods. Items such as refried beans, peanut butter, pumpkin purée, or squash purée should not be home-canned. (Cooked cubed pumpkin can be canned at home, but cubed squash will compress during heating and become too thick; it should not be home-canned).

·        Lard. It is too dense and too fatty to safely can at home.

·        Pickled eggs. They are too dense to safely can at home. There are no tested recipes for canning pickled eggs.

·        Dairy products. Soups (or other foods) made with cream, milk, butter, or other dairy products are not recommended for home-canning. Like oil, dairy products are low-acid and support an environment which fosters botulism growth at room temperature. The fat in dairy products can protect botulism spores and toxins from heat during the canning process. When milk is over-heated, the milk proteins drop out of suspension and separate. The amount of heat that would need to be used to kill botulism is so extreme that the food would be rendered inedible. For this reason, canning milk or canning butter is not recommended as a safe procedure for home canners.

·        Cornstarch. Cornstarch is a thickener that breaks down during processing; more importantly, it retards heat penetration. When a thickening agent is needed, use Clear-Jel, which is a modified corn starch formulated for canning. Clear-Jel does not break down in acid food mixtures, and it does not thicken so much that it interferes with the process of heat-killing any pathogens. Please note that processing times listed in published reference books are not sufficient for using any thickeners other than Clear Jel. Unfortunately, this product generally can't be found in grocery stores, but it can be found online.

·        Flour. Some people believe they can make "cakes in a jar" or other foodstuffs that contain flour. This is strongly inadvisable. Home canned flour products , such as breads and doughs, are considered very prone to botulism. No one has yet been able to come up with a reliable recipe and canning direction that doesn't produce botulism some of the time. Flour products are low-acid and "baking" them in a jar is not "canning"; it is not recommended.

The reasons behind the inadvisability of canning these foods are generally due to one of two things: either scientific research has demonstrated that home-canning of such foods is potentially hazardous, or the only way to can them is at such high pressures that the results are unpalatable. In other words, if it's not possible to kill off botulism spores while producing a palatable product, then the food is placed on the "not recommended" list.

There will always be people who think the rules don't apply to them, or believe they're special enough to refute the science behind safe canning. This is the kind of sloppy canning techniques I continuously warn about. Remember, past performance ("Granny always did it!") does not guarantee future results. Canning is a highly developed science, and to assume the rules don't apply to you is asking for trouble. Be safe. - Patrice Lewis

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DearXXXX,

Thank you for all the great information that “Survival Blog” provides, and my compliments to DDR for all the information provided in "The Joy of Canning"! I'd like to expand on this work to describe what I call "Canning Marathons"-- 12 to 14 hour days spent producing 40 to 80 jars of home canned produce. Just for reference, I'm part of a family heritage that has grown and put up their own food for many generations.

Canning marathons are needed for serious ”preppers” or anyone that is dedicated to growing, processing, and preserving their own food. The following information doesn't count all the other homegrown food that is dehydrated, frozen, grains, dry beans, fresh produce, and more that is needed for a year's food supply.

The first step for a year's family food preservation is to grasp the enormity of this endeavor. To simplify the math, figure a 350-day year, a one-pint (16 ounce) canning jar equals a 12 ounce store-bought can (what most people are familiar with), and the contents of a one-pint jar equals one pound of garden produce or meat to be canned. Yes, I realize that's not totally accurate, but it simplifies the math. So, if your family uses (or wants to use) two cans of fruit/vegetables/sauce/canned meat per day for the entire year, you will need 700 pints or 350 quarts of home-canned food per year. It also means about 700 pounds of food ready to be put into jars. If you use four cans per day (for a big family), then double the numbers.

My family of five puts up an average of 700 jars of produce in various sizes of jars each year.. We also want to have at least one-half to one full year's worth of canned food on hand, in case of a year of low garden production or TEOTWAWKI-type events. So that means that at the beginning of the canning season, we should have 350 to 700 canning jars that are still filled with the previous season's harvest. While planning a garden, we take into account how many canning jars are still full in the spring. If we have lots of canned tomatoes, we grow fewer tomato plants. If our canned tomato supply is low, we grow extra tomato plants. Therefore, we have 1000 to 1400 jars filled and neatly stored in a large, walk-in pantry.

Obviously, dating and rotating the jars is extremely important. If my family, on average, cans 50 to 70 jars of produce per marathon, it takes 10 to 14 long, canning marathons to produce the 700 jars needed.

My suggestions for canning marathons are:

* Have a good quantity of the necessary equipment-- at least two or three pressure canners and/or two or three hot water bath canners, a large number of two-, three-, or four-gallon kettles/pots, (I use only stainless steel kettles), several 5-gallon pails for compostable waste, baskets of produce, numerous sharp knives (I have a dozen Chicago Cutlery steak knives and others for use), commercial-size stirring spoons, and large ladles (for the large kettles).

* Additional burners (beyond the four on an average kitchen stove) are needed. I add two Coleman camp stoves to give me an additional four burners. Propane burners are the easiest to use because they have immediate temperature control. It is far easier to find the "sweet spot" quantity of heat, to maintain an almost exact amount of pressure in a pressure canner, when using gas burners rather than electric ones. I process everything at 12 pounds of pressure. That way, it gives me a little extra time to adjust the burner heat if the pressure goes up or down since it's impossible to have your eyes on the pressure gauge every minute whilling getting the huge amount of other processing work done.

A minimum of two pressure canners are needed to can any quantity of jars because of the long times it takes to heat, process, and cool down each batch ,even when I work alone. If two or three people are working together efficiently, they can keep three pressure canners busy--one being filled, one processing, and one cooling. With some overlap all of this is repeated over and over again until all the available produce is canned. Don't forget that there is alot of produce prep work, jar washing, kettle washing, and clean up to be done, too.

The double decker pressure canners are extremely valuable for processing pint jars. They can hold 18 pints at one time. With two double decker pressure canners, it only requires two batches of jars in each of the two pressure canners to produce 72 pints of produce; that's an easy half marathon day.

The only big disagreement I have with what DDR wrote is the need to 'sterilize' the jars before filling. The jars certainly need to be clean, but they are not truly sterilized until they go thru the pressure canning process. Using precious time and the limited number of stove burners to heat the canning jars will greatly slow down the number of jars that can be processed during the canning marathon. As DDR wrote, you should never put cold jars into hot water or hot jars into cold water, so heating the jars does have a value for hot packing. I've never broken a cold jar from pouring hot liquid into it, but I've broken several jars by putting a cold pack jar into hot water-- the bottom breaks out. Therefore, I always put cold pack jars into water than is no hotter than 'warm”.

I take the rings off the jars after they are sealed, as the lids and rings have the potential to rust or stick together, making the jar harder to open. An additional value is that the rings will last for many years longer if they are removed, completely air dried, and stored in a dry place.

Hope you all enjoy your ”canning marathons” as much as I do! Seeing an entire counter top covered with processed and sealed canning jars after a day's hard work still gives me a thrill!!! - Mountain Firekeeper

 

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