Category Archives: Food Safety

Pop Quiz: What Time Is It?

dial=gauge pressure cannerDial Gauge Testing Time! As the temperatures warm (or not so much) let that be a reminder it’s the time of year again to get your pressure canner dial gauge tested. Dial gauges need to be tested for accuracy before each canning season or after dropping or banging it.

The manufacturer of your pressure canner is best able to provide you with instruction for inspection/gauge testing. Some companies require that you mail it in to them. You may also ask at a local hardware store or contact your local Cooperative Extension office, as some of them will do gauge testing for some brands of dial gauge pressure canners if they have an agent at that location who is trained to do so. Select your state from the drop-down list on this search tool to locate your county office:  Find Your Local Extension Office.

Also as part of an annual “check-up”, make sure all parts of your pressure canner are in good condition.  If your canner has a rubber gasket, make sure it is flexible and soft, not brittle, sticky or cracked. Check the openings on any small pipes or vent ports to be sure they are clean and clear of any debris.

If you don’t have a pressure canner and are thinking about getting one, then make sure you select a pressure canner that is capable of holding at least 4 quart-size jars upright, on the rack, with a lid that secures airtight. If it is smaller than that, we do not recommend it for home canning using USDA canning procedures.

Whether your pressure canner has not yet been used this season or is new out of the box, it is a good idea to make sure it is working properly before preparing a canner load of jars.  Put several inches of water in your pressure canner, and pressurize it as if canning.  Make sure it gets to the pressure needed and can be maintained there without leaking.  This is a good time to practice de-pressurizing the canner as if it had jars in it and then go through the steps for opening your canner as desired.  Read step-by-step procedures for using pressure canners on the NCHFP website.

IMG_1027This blog post contains a revision of Can Your Vegetables Safely by Dr. Elizabeth Andress.

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Simply Soup

tomato vegetable soupThis cold, long winter will be a memorable one for many. Hopefully you made use of your reserve of fresh and preserved foods, but you may have made your way through it all! If you are already thinking about preparing for next year, then you may like the idea of canning soup to bring delicious and nutritious warmth during the coldest days.

Different from the vast majority of USDA canning recommendations, our recommendation for IMG_1071Canning Soup allows you to have some choice of vegetables, dried beans or peas, meat, poultry, or seafood. However, that does NOT mean that it is safe to can just any combination and proportions of ingredients, sorry!  For your safety, please regard these key precautions before before getting out your pressure canner (and yes, a pressure canner is required for canning soup):

  • Our recommendation for canning soup does NOT allow you to include noodles or other pasta, rice, flour, cream, milk or other thickening or dairy ingredients.
  • The procedure for canning soup says “Each vegetable should be selected, washed, prepared and cooked as you would for canning a ‘hot pack’ according to USDA directions”, which means that there must be a canning recommendation for each added ingredient. As examples, for this reason we cannot recommend adding cabbage nor cured meats like cured ham to canned soup.
  • It is also very important when canning soup that you “Fill jars halfway with solid mixture.” The reason behind filling the jar 1/2 with solids and 1/2 with liquid is to ensure the safety of the product. Our recommendation for canning soup may have a substantial amount of variability based on which vegetables and/or meats are selected and in what proportions. The 1:1 liquid to solid ratio ensures that a certain rate of heating occurs so Soup filled jars half and halfthat the dangerous bacterial spores of botulinum will be destroyed no matter which ingredients (that are noted in the recommendation as acceptable) you select and prepare as directed. Heat transfers more easily and quickly through liquid than through solids and dense mixtures, so a new canning process time would have to be determined through product testing if you were to increase the solid to liquid ratio.

If you choose to follow canning recommendations from another source, then you are choosing to trust their product testing of their recipe, procedure, and process time — they are responsible for their own product testing and you could certainly contact them if you have questions about their recommendations.

Our canning VegSoup1recommendations are meant to be followed exactly as written, and we unfortunately cannot provide individual testing of homemade recipes. If you are still wondering if you can can your favorite homemade soup recipe at home, please read our Burning Issue: Canning Homemade Soups.  Remember too that once you can soup as recommended, you can add your choice of ingredients AFTER you open the jars and re-heat the soup for serving!

Tips for Gifting your Home-Canned Goodies

Giving home-preserved gifts adds a personal touch, but you do take on the added responsibility of vouching for the safety of the foods you give. As tempting as it may be to impress your recipients with a brand new, never-before-tasted canned creation, your first measure of safety is to use tested recommendations from reliable sources. Instead of experimenting with recipes, get creative with the way you package your home-preserved gifts.

If you use an attractive canning jar of a unique size (12 oz., for example) and you can’t find canning recommendations for that size jar, be sure to use the next biggest size jar that does have canning recommendations (so in the example of the 12 oz. jar, follow the process time listed for pint size jars). Otherwise the product might be under-processed and risk spoilage or causing sickness. Also, be aware that there are lovely jars out in the market place that are NOT recommended for canning. Some jars are intended for other uses, and even if they look like canning jars they may not be tempered to withstand the intense heat of canning or temperature changes that occur in taking jars in and out of canners. (These jars might work well to gift beautiful dried fruits, however!) Our canning recommendations are for use with Mason-type home-canning jars and two-piece lid systems.

Decorative labels are available from jar manufacturers and other companies. As you label your precious products, remember to include the creation date, and consider telling your recipient how long the product will stay “good” (usually one year for best quality with most home-canned foods). If you have room, also include the ingredients (especially if the product contains allergens) and storage instructions like “Store in a cool, dry place and refrigerate after opening.”

If you didn’t already do your canning for gift-giving, then here are a few festive ideas using seasonal ingredients:

Spiced Apple Rings, Apple Butter, Sweet Apple Relish

Citrus Marmalade

Chutneys

Cranberry Sauce, Cranberry Marmalade, Cranberry Conserve

Flavored Vinegars

There are also a few popular holiday gifts that are NOT recommended for home-canning. Don’t risk the health of your loved ones — try the alternative suggestions instead:

Herbed Oil Infusions (try Flavored Vinegar instead –you don’t even need to can it!)

Canned Breads (instead, package dry ingredients and make a tag with baking instructions)

Canned Chocolate/Fudge Sauce (make this Freezer Chocolate Fudge Sauce instead)

This entry was inspired by Resources for Home Food Preservation Gifts by Brian A. Nummer. For more canning-related gift ideas, see Looking for a Gift that Keeps Giving? Try a Dehydrator! and Holiday Gifts for the Home Food Preserver .

 

Can I Can in a Multi-Cooker?

cartoon cookerYou may have seen advertisements for electric multi-cooker appliances now containing “canning” or “steam canning” buttons on their front panels. Before you make a purchase, we want you to be aware that we do not recommend our canning processes for use in electric multi-cookers at this time.  We do not know if proper thermal process development work has been done in order to support the canning advice that is distributed with these multi-cooker appliances. The way the USDA, National Center for Home Food Preservation and University of Georgia process development work has been done would not yield results expected to be transferable to these electric cookers.

Our process directions for low-acid foods, for example, were developed for stovetop pressure canners which hold four or more quart-size jars standing upright. Even if there are referrals to the National Center for HFP in the instructions for canning in the manufacturer’s directions, we do not currently support the use of the USDA canning processes in electric, multi-cooker appliances. If you are canning low-acid foods and the proper amount of heat is not delivered to all parts of the food in the jars during the process, then the risk is botulism food poisoning in under-processed foods.cartoon pressure canner

Some of the major reasons we cannot recommend using electric multi-cookers for canning:

  1. No USDA thermal process work has been done with jars inside an electric pressure cooker of any kind. Thermal process canning work relates the temperatures in the jars to the temperature inside the canner throughout the processing. It is not the temperature or pressure in just the canner that matters, but ultimately the temperature and heat distribution inside the jars is most important for the destruction of microorganism in the food product. The position of jars in the canner and flow of steam around them also impacts the temperature in the jars.  For example, there would be expected differences in jars piled together on their sides from those standing upright.
  2. What matters is temperature, not pressure.  Even if a manufacturer says its cooker reaches the pressure required for canning, that does not prove the food in the jars is heated throughout at the same rate as in the canner used for process development.  What is important is what temperature relates to the pressure reached in that cooker, and what the temperatures are throughout the whole canner environment.  And does the temperature stay at the minimum required the whole process time? If air is mixed in the steam, the temperature is lower than the same pressure of pure steam. (That’s why a proper venting process is so important in pressure canning – to obtain as pure a steam environment inside the canner as possible.) How does the user adjust for altitude changes if the cooker is set to reach only one pressure? If the pressure actually obtained reaches a desired temperature, can the user actually verify the pressure reaches the stated description and stays there throughout the continuous process time? We do not know of ways in which these questions have been answered.  (And unfortunately we do not have a budget to be able to buy and use all of the versions in the marketplace.  We have been able to read some user manuals that do not answer these questions, however.)
  3. In order to ensure the safety of the final product, the temperature in the canner must stay at minimum throughout the process time, so do power surges or drops with an electric canner cause the temperature to drop too low?  How will you know if that happens?
  4. USDA process times rely on a combination of heat from the time the canner is coming to pressure, during the actual process time, and then during the early stages of cooling the canner and jars. Even after the heat is turned off under the canner, at the end of the recommended process time, the food remains at high enough temperatures for another period of time that can still contribute to killing of bacteria. This retained heat while the canner has to cool naturally to 0 pounds pressure before opening is used to advantage in calculating the total sterilizing value of the process to preserve some food quality. There is no way at this point in time to know exactly the percentage of contribution for each of the canning recommendations. Therefore, we emphasize that the canner size and steps in managing the pressure canning process from start to finish (heat up to cool down) are important to maintain. For example, if anything is done to shorten the cooling period, including using a very small cooker or force-cooling the canner, then the food could cool down more quickly than expected, and be under-processed. (This is one reason we recommend using only pressure canners that hold four or more filled quart-size jars, upright on a rack, with the lid fastened in place. It is a way to help judge that the cool down period will not be too short.) Bacteria are not killed in the food only during the process time; the time it takes the canner to come up to pressure, the process time, and the cool-down time all matter.

Please note: This statement about electric cookers does NOT include the Ball Automatic Home Canner for acid foods only, which is electric, but (1) is not a “multi-cooker”, but a dedicated canner, (2) comes with its own instructions and pre-set canning options for specific food preparations, and (3) has had thermal process development done specific to that canner to support the recommendations with it.

Editor’s Note (February 12, 2015 ): We are aware that Jarden Home Brands will be releasing a new electric boiling water canner, multi-cooker appliance. More information will come as we learn about this new device.

For more information about canning in pressure cookers, please read “Burning Issue: Canning in Pressure Cookers”: http://nchfp.uga.edu/publications/nchfp/factsheets/pressurecookers.html