Avoid Common Canning Mistakes - PVP24

Show Notes

It is wonderful to see that canning has continued to be popular after all the doomsday canning driven by the economic collapse of 2008

Canning is simple and straightforward but there is an abundance of less than stellar information roaming about that can lead to spoiled food, short shelf life, bad seals, broken jars, wasted food, and wasted time--and illness or death.

Remember: always remove rings (bands) to store your home canned goods. And don't stack the jars either...jars stacked only for the photo!


Be sure to use current recipes. Check the safe canning guidance with the USDA and university extension(s). Be sure that you understand the recipe(s) and the equipment that you are using. Simply having a mason jar seal isn't assurance that the food is shelf stable and safe to eat after storage. So, please proceed safely and as always at your own risk. Botulism is a real risk! Improperly canned food is the perfect environment for the botulism spores to grow!  

And if you think the risk isn't real, check out this case from Ohio (July 2015). A home canner didn't process home canned food properly and then served it at a potluck! Sadly, the result was a break out of botulism.


Let me lay the some groundwork. My goal of canning is to have quality, safe, shelf stable food on the pantry shelf. Our home canned goods replace store bought canned goods like soups, meats, fish, beans, relishes, pickles, and so forth. I don't want to take unnecessary risks that will waste time, money, and energy or make my family or friends sick.

Before starting any canning session, be sure to allow adequate time! Listen to How to be Ready to Home Can to have everything on hand for canning.

Canning Basics

If you are new to canning or if you want a refresher it is crucial to check current resources. 

There are university extensions in every state to help us can safely, here are some of my favorites.


Check your equipment and be sure that you have everything on hand before starting a canning session.

  • Jars.
    • Use clean jars that are free of nicks and cracks.
    • Avoid using jars that are not marked "mason" for home canning--this is particularly important for pressure canning. There are some exceptions but beware of the type of jar you are using.
    • Ball and Kerr jars. Jars with two-piece lids that you are most likely to find on store shelves. USA.
    • Bernardin jars. Jars with two-piece lids. Canada.
    • Leifheit jars.  These sexy jars offer two-piece lids. Germany.
    • Bormioli Rocco. Jars with one piece lids. Italy. These jars have a one-piece lid which isn't an USDA approved lid. But, the lids do have a button to indicate sealing. They are pretty but given the price for replacement lids they won't be a canning staple for me.
    • Weck jars. These are canning jars are safe to use for home canning. I use them and they are lovely. The only bit to note is that the USDA hasn't developed guidelines for the use of these jars. Keep in mind that that doesn't mean that they are not safe; only that the USDA hasn't developed guidelines. Also, keep in mind that safe canning recommendations are based in part on the jar size, shape, and material. I recommend using them after you understand safe home canning and have a bit of experience under your belt. Learn about Weck canning jars on Weck's website.
    • Orchard Road jars. Jars with two-piece lids. This relatively new company's jars are manufactured in China so I give them a pass. 
    • Vintage lovelies. Yes, we all have them and they are best for dry storage. 
  • Lids.
    • Use new lids. Used lids might seal but the the sealing compound is degraded after it has been processed. Use new lids even if reprocessing jars that failed to seal. Keep in mind that the folks who make Kerr and Ball lids indicate that the lids are to only be used once. Let's be safe here and simply use new lids every time. Lehman's carries bulk lids (made in USA and BPA-free) so that you can always have lids on hand. 
    • Weck lids. Rubber seals should not be reused. Of course, broken or cracked lids should not be used and the clips need to be in place for canning.
    • One-piece lids. One-piece lids do not have the USDA stamp of approval. Why? Unlike two-piece lids there isn't more than one why to check that the jar is properly sealed. Since we know people will go down this road--use the proper lids. Use lids that are specifically for canning. Or branded lids from Bormioli Rocco or companies that offer canning jars with one-piece lids. The lids should be appropriate for high temperatures and have a button to indicate a good seal. And maybe try this after you have some canning experience. Be safe and proceed at your own risk.
    • Tattler lids. These lids are not approved by the USDA but I recognize that many people are interested in them because they are reusable. I don't recommend them as I don't think the reusable part offsets the risks. Also, in my personal experience I've seen the failed seals out of the canner and months down the road on pantry shelves. The wasted food, time, energy makes these lids a non-starter for me. Read guidance from the University of Wisconsin Extension, Safe Preserving: Using Tattler Lids.
  • Rings. Avoid rings that are dented and rusted. Damaged rings can prevent the lid having contact with the rim or might be difficult to remove after processing.
  • Pressure canner.
    • Inspect canner before using.
    • Check that the vent isn't plugged with food.
    • Check that the overpressure plug is in place.
    • Check that the gasket is in good working order and replace if needed or apply oil if needed on a metal to metal seal.
    • If the dial gauge hasn't been inspected in the last year it should be inspected prior to use or  be sure you have the weighed gauge. Even brand new dial gauges should be checked!
    • Read the owner's manual. 
  • Boiling bath canner or large stockpot.
    • Be sure that the pot you are using is large enough for the jars you want to can plus 1"-2" inches of water to cover the jars.
    • Be sure to allow another 1"-2" of airspace above the water so the water doesn't boil over.
    • Lid. Boiling bath canner must be used with a lid during the entire processing time.
  • Steam canner.
  • Rack for canner. Be sure to have one. Not using a rack can mean broken jars.
  • Workspace. Workspace should be cleared. All equipment and tools out, clean, and ready to go.
  • Funnel. Very useful to make jar filling quick and easy. It can also keep jar rims clean.
  • Jar Lifter. 
  • Chopstick or other plastic air bubble remover.
  • Ladle, spoon(s), measuring spoons, measure cups, and perhaps other standard issue kitchen tools.
  • Labels or sharpie. All canned goods should be marked with the contents and date.
  • Timer, watch, or clock.
  • Towels.
  • Potholders.

Canning Recipes

  • Recipes. Use current recipes. If you are in doubt check USDA and university extensions for current guidance for food that you would like to preserve. Some extensions have phone numbers! You can call and speak to an expert! There are email addresses for many extensions! Send 'em email!
  • Acidifiers. Use commercially made vinegar that has 5% acidity. Use store bought lemon juice. Use citric acid. Using homemade vinegar or fresh squeezed lemon juice may not have the proper acidity level for safe canning. Do not make adjustments to recipes that include both low acid and high acid ingredients to include more low acid foods. For example, when making salsa keep the proportions of tomatoes, onions, peppers as indicated in the recipe. Do not omit or decrease vinegar or lemon juice indicated in the recipe. Side note: A quality pH meter and an understanding of pH is vital if you insist on not using commercial products. 
  • Thickeners. No corn starch, flour, arrowroot, or other thickeners. Thickeners can prevent the food from being heated to the temperature required and processed for the time required to make a safe home canned product. [Added 8 October 2015: This refers to modifying reliable recipes to add these products. There are reliable recipes that include small amounts of corn starch and flour.]
  • Starches. Rice, noodles, barley, grains, etc. Adding starchy food can prevent the food from being heated to the temperature required and processed for the time required to make a safe home canned product.
  • Dairy. Skip adding any dairy. Be aware that some store bought seasoning mixes contain powdered whey and these should not be used for home canned goods. [Added 8 October 2015: This in the context of changing recipes to add dairy. There are recipes that include diary or eggs. I happily can lemon curd for example.]
  • Pectin. If you are adding pectin add it per the recipe. Liquid pectin and powdered pectin are used differently so be sure you are using the product correctly. A less junk in the box pectin is Pomona's Pectin. It is a common mistake to overcook sweet preserves with added pectin. Just follow the recipe. I am a fan of kicking the boxed and bagged pectin habit. So, I encourage you to seek out non-pectin recipes and spend that money on jars and lids!
  • Salt isn't required but some recipes may taste better with some salt. [Added 8 October 2015: Salt is required for fermented pickles or sauerkraut.]
  • Sugar isn't required for canned fruits but geez that doesn't sound so great. 

Selecting Jars 

  • Jar size. Follow jar size guidance indicated in the recipe. For example, the guidance for fish except tuna is 1/2 pint, pint, or quart jars. Tuna should only be canned in 1/2 pint or pint jars. 
  • Then there are nice things like 1 1/2 pint jars that are perfect for asparagus and 1/4 pints are perfect for a jam sampler gift basket.

Filling Jars

  • If filled jars will be processed less than 10 minutes, the jars must be sterilized. If the filled jars will be processed longer than 10 minutes then sterilization is not required. Of course, wash jars and rinse well before using.
  • Headspace. Always allow the appropriate headspace. Measure to be sure. 
  • Packing methods
    • Hot pack. Hot pack is hot pack. Not warm pack not cool pack. Hot jars, hot food, into hot canner: 180 degrees.
    • Raw pack. Packing raw into cool jar, into cool canner: 140 degrees.
    • Jars packed for steam canning must be hot packed.
  • Removing air bubbles. Don't guess. Take the time to carefully remove air bubbles from each jar with a non-metal utensil. Metal utensils can scratch the jars which in turn can break during processing.
  • Cleaning jar rim. Clean with a lint-free cloth. Use vinegar on the cloth if you are canning meat, fish, or broth, etc. to be sure that there are no oils or fats on the rim.
  • Lids.
    • Always, always use new lids! Again, always use new lids. The sealing compound, plastisol, is intended for one-time use and when re-processed the lid cannot maintain the same tight seal.
    • Remember sealed jars are not an indicator of properly home canned food.
    • Ball and Kerr lids should not be boiled but they can be kept warm at a simmer--but simmering isn't necessary. The lids need only to be washed and rinsed prior to use
  • Metal one-piece lids and Weck rubber seals are intended to only be used once for canning.
  • Rings. Simply screw lids on finger tight. Screw until you meet resistance--don't wrench lids on. The job of the ring is to keep the lid in contact with the rim of the jar to ensure a good seal. If the ring is screwed on too tight the lid could buckle and the lid fail to seal.

Filling Canner 

  • Jar placement. Jars should be placed on a canning rack to prevent breakage. A rack should be used between layers of jars if you are canning two layer. Remember work arounds are just that, workarounds until you get the proper piece of equipment.
  • Water bath canner's water level. Jars should be covered by at least 1"-2" water. 
  • Pressure canner's water level.  2"-3" of water should be in the bottom of the canner before you put jars in it. Follow the manufacturer's instructions. If you are processing multiple batches back to back--be sure to check the water level. Also, there are some special instances in which additional water is required because of a special canning procedure--just be sure to follow the guidance.
  • Steam canner's water level. Be sure if you are canning back to back batches that you double check the water level. See manufacturer's recommendations. For example, Victorio.


  • Adjusting for altitude. Always adjust for altitude
  • Processing times. Follow guidelines for processing times. Don't guess or estimate.
  • Timer for boiling water canning.
    • Start timer the when the water in the loaded canner starts boiling.
    • Processing time ends when the time indicated in the recipe has elapsed. 
  • Timer for pressure canning.
    • Processing time doesn't start until venting is complete and the required pressure has been reached.
    • Canner must be vented for 10 minutes. Venting ensures that the air is removed from the jars and the canner. Some pressure canner manuals indicate venting for 7 minutes--note that the updated guidance from the USDA is 10 minutes.
    • If the pressure falls below the pressure required for processing at any time during processing--the timer must be restarted! 
    • Again, keep an eye on your dial gauge and make sure the pressure is maintained for the entire processing time.
    • Weighted gauges--check your owner's manual for more information.
    • Processing time ends when the time indicated in the recipe has elapsed.
  • Timer for steam canning.
    • Processing time starts when the dial on the canner indicates the proper temperature has been reached.
    • During steam canning it will be necessary to monitor the dial to maintain the temperature required while not keeping the water at a vigorous boil.
    • The processing time for steam canning will be the same as boiling bath canning.
    • Processing time ends when the time indicated in the recipe has elapsed.
    • Remember steam canning is only appropriate for high acid foods like sweet preserves, salsas, and pickles.

Removing Jars from Canner

  • Boiling water canning. Turn off the heat and wait 5 minutes before removing the jars.
  • Pressure canning.
    • Allow canner pressure to reach zero naturally. Do not attempt to speed up depressurization by knocking or removing weighted gauge or pressure regulator. Do not plunge canner in cold water or pour cold water over the canner. Why? It will cause siphoning of the liquid from jars! So, just be patient.
    • After canner has reached zero pounds of pressure remove the weighted gauge or the pressure regulator.
    • Allow canner to further cool for 10 minutes before removing the lid. Always remove the lid away from your face.
  • Steam canning. Turn off the heat and wait 5 minutes before removing the jars.

Cooling Jars

  • Do not tighten the rings.
  • Place jars on a protected surface. I use towels on the counter. 
  • Leave an inch or two between jars.
  • Jars cooling slowly is a good thing and critical to safe home canning.
  • I like putting a little paper sign to remind folks to not disturb.
  • Protect jars from drafts. 
  • Do not move or disturb jars for 12-24 hours.
  • Check that jars are properly sealed. Jars that do not seal can be re-processed with new lids or refrigerated to eat in the next day or two. 

Time Savers to Avoid

There are so many ideas swirling out there--these are just a couple that I find particularly problematic.

  • Canning dried beans without hydrating. This is not an approved method to can beans. Why? Beans that have not been properly hydrated and heated in turn are not processed at the required temperature and time to ensure safe canning.
  • "Canning butter". Again this is not an approved method to preserve butter. Why? The idea is that melted butter is put into canning jars, shaken to prevent separation, and then stored on the pantry shelf. Why would we do this? Safe? No.
  • If in doubt, double check. 

Unsafe Canning Methods

I am not going to get into all the gory details here as the same issues applies to these methods: it is crucial that food in the jars reaches and maintains the temperature necessary to ensure the food is safe to eat and there is no opportunity for cooties to be introduced. These methods do not preserve food in a way that is safe and shelf stable.

  • Open kettle canning.
  • Oven canning.
  • Microwave canning.

Storing Home Canned Products

  • Remove the ring for storing.
  • Cool.
  • Dark.
  • Dry.
  • Shelf life. One year is generally considered the shelf life of home canned foods.
  • Spoilage and leaking jars. When in doubt, throw it out. Do not test. Do not guess. Do not experiment. 

Care & Storage of Canners

  • Wash and dry throughly.
  • Mineral build-up and discoloration can be prevented in your aluminum canner by adding 2 tablespoons of white vinegar to the water in the canner before you can. Discoloration in aluminum canner be removed with 1 tablespoon of cream of tartar per quart of water. Add enough water with cream of tartar so that it is above the discoloration. Boil. Cool the pot, wash, rinse, and dry.
  • Store the canner without the lid engaged to prevent funky smells and with paper towels or old dish towels to absorb any moisture.
  • Store pressure canners with lid upside down on top to protect the dial and so forth.

Remember check online for current guidance. If you have questions, always ask.

Be safe and eat well.




  • Special thanks to Dale, Nia, and Steph for all the love and support! 
  • Raleigh, the guy I love to hate when it comes to all things internet.
  • Aaron Glasson, Permaculture Velocity logo
  • Music: Tell Somebody by Alex Beroza featuring AdmiralBob, digccmixter, licensed under Creative Commons 3.0
  • And to all those podcasters out there sharing good information on podcasting for those of us just getting going with this podcast thing! Thank you!