Tag Archives: pressure canning

Get Ready Now for the Summer Harvest

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If you are thinking about joining the trend in our communities to preserve food this summer, start planning and preparing now! Start by checking your equipment and supplies. Proper equipment in good condition is required for safe, high quality home canned food, for example.

If you’ve not yet purchased your needed equipment, there are two types of canners to consider: boiling water canners and pressure canners. A boiling water canner is used for canning acid or acidified foods like most fruits, most pickles, jams and jellies. Boiling water canners cost about $30-$100, or can be assembled yourself with a large stock pot, secure lid, and rack to keep jars off the bottom of the pot.

A pressure canner is essential for canning low acid foods such as vegetables, meats, fish, and poultry. Temperatures inside pressure canners reach higher than boiling water canners (for example, 240°F and above as compared to about 212°F). This is necessary to follow the tested processes available to be sure and kill the toxin–producing spores of the bacteria Clostridium botulinum.  If not killed, these spores can grow out and produce a deadly toxin (poison) in room-temperature stored jars of the low-acid foods mentioned.

You have two choices for type pressure canner: a dial gauge canner or a weighted gauge canner. Most steps in managing the pressure canning process are the same, but the two styles have different types of gauges to indicate the pressure inside the canner. Expect to spend $100-$150 or more on a pressure canner.

If you use a dial gauge canner, then it’s important to have the gauge tested for accuracy before each canner season or if you drop or damage your gauge. It isn’t as easy as it used to be to get gauges tested. Try a local hardware store or your local Cooperative Extension agent, even though not all still provide this service. For either type of canner, check that the rubber gasket is flexible and soft, and if it is brittle, sticky, or cracked then replace it with a new gasket. Also check that any openings, like vent ports, are completely clean and open.

You’ll also need jars, lids, and ring bands for canning. When getting started, new jars are a worthwhile investment (versus purchasing used jars from a yard sale or flea market) because very old jars may break under pressure and heat. Mason-type jars of standard sizes (e.g., half-pint, pint, and quart) for the tested processes available from science-based sources such as USDA and your land-grant university are recommended. Make sure those jars are manufactured and sold for canning purposes; not all glass and Mason-style jars are tempered to prevent breakage with the extreme heat and temperature swings during canning. When you actually get to canning your harvest, be sure to follow manufacturers’ advice for preparing your jars and lids. In addition to standard cooking utensils like cutting boards and bowls, a jar funnel, jar lifter, lid wand, headspace tool, and bubble-freer are items that you will want to have handy for canning.

If you are freezing your harvest, be sure to use packaging such as plastic bags or rigid containers that are intended for freezer storage of foods.  Not all plastics are the same, and you want materials that will hold up to freezer temperatures as well as protect your goodies from damaging air and mixtures of odors.

Growing your own? You may be lucky enough to have previously started keeping garden records so you remember the name of that great tomato or pepper variety you have liked this past year. If not, think about planning to keep records this year. A garden journal might include variety, seed source, date planted, date harvested, notes on how it grew and resisted disease, and your personal evaluation of the crop.

A final must is reliable, up-to-date canning and other food preservation instructsetp5ions. Specific kitchen equipment or ingredients could be needed to follow directions as they are written for food preservation. And in the case of canning especially, very significant food safety risks by following unsound recommendations. Reliable, up-to-date canning instructions are available at the NCHFP website, the USDA Complete Guide to Home Canning, So Easy to Preserve, or the county or local area Extension office in your state.

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This entry contains information from Keep A Garden Record Book—Thomas Jefferson Did by Wayne McLaurin.

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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.

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!

Preserving Potatoes

potatoes

Not known for their fragility, potatoes are a robust, starchy tuber in the nightshade family (along with fellow Solanaceae family members tomatoes, eggplants, and peppers). Potatoes pack a nutritional punch, weighing in with substantial amounts of potassium, fiber, protein, vitamin C, Vitamin B-6, Magnesium, and a lesser but still notable amount of Iron.

It’s easy enough to store fresh white potatoes for up to 2 months in a cupboard kept at 50-70°F (sweet potatoes last only 2-3 weeks). But what if you want them to last even longer?

Interestingly, storing white potatoes in a refrigerator is likely to diminish their quality and they are expected to last only 1-2 weeks there. Alternatively, you could cook and mash them, stuff them, or scallop them for freezer storage, but again, they will retain best quality only for a few weeks in the freezer.

Drying is an option for making potatoes last longer. Wash, peel, then cut potatoes into 1/4-inch thick shoestring strips, or cut into 1/8-inch thick slices. Steam blanch the prepared pieces for 6-8 minutes or water blanch them for 5-6 minutes. Plan for a drying time of 8-12 hours in a dehydrator and up to twice as long in an oven, depending on circulation. If you dry sweet potatoes and want to rehydrate them for a recipe, combine each cup of dried pieces with 1-1/2 cups water and let them soak for 30 minutes.

As for canning potatoes, our recommendation is to peel potatoes before canning. That style of preparation is how the research was carried out to determine the recommended processing, and in order to know that the peeling does or does not make a difference, research would need to be done with unpeeled potatoes. Different assumptions might be needed in assessing just how many spores of C. botulinum or other bacteria might be present at the start of the process and what amount of heat might be needed to meet standards for the risk of possible survivors. We do not know of research of canning potatoes with peels left on, so we recommend the preparation steps provided with the process recommendation, especially because there is a possibility that the deviation could result in a less safe situation. Also due to safety concerns, it is important to use potatoes that are only 1 to 2 inches in diameter if you are canning them whole.  These are sometimes described as “new” potatoes; the idea is to use less mature, smaller potatoes which tend to be less starchy than older, “grown-up” potatoes.

White potatoes for canning should be the “waxy” or “boiling” kind.  Different types of potatoes have different amounts and types of starches and they react to heating differently.  You want a potato that keeps its shape and texture well after a lot of heating, and not one that falls apart, becomes “fluffy” after cooking, and is better for mashing. Most red-skin potatoes are of lower starch than baking potatoes  and work well for canning. Many white round potatoes with thin skins fall into this category with red-skin potatoes too. Russets are not good for canning but are  good for baking (they have a high starch content).  Yukon Gold may not be the best potatoes for canning.  While they seem good for boiling, they do tend to fall apart when overcooked.  From what we have read, there is a wide variety in the types and amounts of starches in blue potatoes, so not all blues are the same, just like not all white potatoes are the same in these characteristics.

Sweet potatoes can be slightly larger, but medium-sized potatoes should be cut to fit in the jar in uniform-sized pieces. Note that the sweet potato pressure canning process time is significantly longer than for white potatoes.

Sweet potatoes can have a sugar syrup for canning, if you like that style. But otherwise, all potatoes — white or sweet — should have fresh, boiling water prepared to pour over the preheated potatoes.  Do not use the cooking liquid.  That cooking water contains a lot of starch that comes out of the potatoes and the process time was determined using fresh boiling water to cover.  The added starch can create  a safety problem by slowing down heating of the potatoes in the canner, and it also creates a very unappealing pack with possible masses of gelled or congealed starches around the potatoes.  If you have spoilage, this makes it very hard to see the signs of some spoilage.