The Basics of Pressure Canning: Things to Consider When Getting Started

The basics of Pressure canning

Have you ever been interested in making your own safe,  canned food at home? It is easier than you think!  What can seem intimidating at first, is a very simple process once you get the hang of it.  And as long as you follow the most up to date procedures recommended by the National Center for Home Food Preservation (click HERE for link directly to their website), you can be sure the food you make for your family is safe

What holds people back?

  • Fear of food poisoning, specifically botulism.  Botulism is scary, and the fear holds many people back from preserving.  Although Clostridium botulinum spores themselves (the bacteria responsible for botulism) are not toxic, when put into a low acid (alkaline) environment with less than 2% oxygen, it will create a toxin that is poisonous and potentially deadly.  But is is important to note that botulism poisoning is extremely rare, and with safe, tested recipes and common sense (when in doubt, throw it out) you can learn this new skill and be confident in what you put up.   You will find many different methods of canning being discussed on the internet, but it is important to understand the fundamentals of canning from a trusted source before you looking to the general web for recipes.  Our knowledge of safe canning practices has changed and improved, so some old family recipes that were considered safe decades ago, may be risky now.

  • Blowing up the house.  I admit this was my fear too.  I have heard stories of dangerous experiences, but most of the time it is due to user error/neglect.  It is important to watch your pressure canner while it is in process to ensure your pressure does not get too high, and to allow ALL pressure to be released before you try and remove the lid.  These are the two critical places that things can go wrong.  Never try to speed up the process.  

  • Time and effort. I will admit it takes a lot of time to can your own food, but it is worth the effort.  There are ways you can streamline the process to make the time work better for your schedule (for example making dinner one night be a canned recipe and get the canner going while you eat dinner).


So what are the important first things to consider for Pressure Canning?

  • It is important to first determine if your recipe is low acid or not, and if it should be pressure canned.  Anything low acid MUST be pressure canned.  This includes all vegetables, broth and meat.  Basically anything other than jelly, pickles, condiments and carefully handled tomato products should be pressure canned.  Personally I can all tomato products aside from salsa, which I prefer to be on the sour side anyway :)  High acid recipes (anything pickled and jams) can be water-bath canned.  This means the jars are completely submerged in boiling water, and processed for a period of time to kill harmful microbes.  Because botulism can not survive in high acid environment, there is not concern for botulism poisoning.  Tomato products are a bit of a gray area in water bath canning because many breeds of tomatoes are less acidic than they used to be.  If water bath canning is to be done for tomato products like salsa and sauce, most recipes will have an added acid component to ensure acid levels are below 4.5, usually BOTTLED lemon juice.  Fresh lemon is also too unpredictable so stick with bottled juice.  
  • Know your altitude.  This is important to ensure the product is processed for long enough time and at the correct pressure.  The boiling point of water changes at higher elevation, so time and pressure needs to be added to ensure safety.  To determine your elevation, a site like this one can tell you your elevation by entering your address.  
  • Determine Processing time and Pressure.  Generally processing time will be the longest time for all individual products in the mix.  The USDA Complete Guide to Home Canning has all the times listed for most meat, fruit and vegetable.  It is a great resource and recommended to have a hard copy in your home.  You can order a copy here.  Recipes will contain the length of time and pressure required, but if creating your own recipe, understanding process time and pressure will be important.
  • Process only safe and allowed products.  Most vegetables and meats can be canned.  Most recipes call for 1/2-3/4 full of solid material and the remainder to be liquid (broth or water) to ensure all contents are heated evenly.  Things that can not be canned include pasta, rice, flour, cream, milk or other thickening or dairy ingredients.  Do not include them in your recipe, rather add after you warm it up.


It is a lot of information to digest, but after you take your first run through all of this will make so much more sense.  I promise!

Ready to move on and learn the steps to pressure can?  Click Here to read the next blog post and learn how. 

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