The Basics of Canning

It’s canning week here at the Tearoom.  Time to take advantage of the harvest and preserve some of that flavour for those long cold winter months.  The bonus is that you can make a few extra jars to have on hand as holiday gifts!

Flickr, bucklava

Let’s start off with 10 basic tips and hints for canning:

1)  Canning works by heating food up to a certain temperature for  a certain period of time so that harmful bacteria and other microorganisms are destroyed and enzymes in the food are halted.  The jars are then vacuum sealed, removing air and keeping new microorganisms from getting into the food.  The vacuum seal occurs when the jars of food are heated and then cooled.  The heating process makes the food and air in the jar expand, while the cooling process contracts the air, pulling the lid down so that it’s concave.  In addition, the rubbery stuff around the edge of the lid softens due to the heat, forms itself to the jar, and seals the jar as it cools.

2)  If you are going to can low acid foods (such as carrots that aren’t being pickled) you need to use a pressure canner.  I won’t be doing any pressure canning.  What I’m sharing will all be done with the boiling water method.  For this, you need to process high acid foods only (jams, jellies, pickles etc.) – ones with a pH of 4.6 or lower.  High acid foods are naturally more resistant to the growth of bacteria.

Flickr, ohmeaghan

3)  Use jars specifically sold for canning.  Do NOT try to reuse jars that you bought food in such as commercial jelly jars or spaghetti sauce jars and the like (even if your grandma used to do this!).  Check your jars carefully to ensure that there are no nicks or chips as you need a smooth rim on the jars so that you can create a proper seal.  Use the size jar specified for the recipe – this is a scientific process and the time, temperature, head space, and size of the jar all must be balanced properly.  Use the lids and rings designed specifically for canning jars.  You can reuse the rings many many times until they get bent or damaged but you must use new lids each time you can.  You should not tighten the rings too much or you can interfere with getting a proper seal.  Just screw the rings onto the jars but don’t try to really tighten them.  You don’t have to throw out the used lids by the way.  I save them (cleaned well) to put on jars that will be used more like canisters for storing products like bread crumbs or brown sugar in my pantry.  I also use them for crafting (are you surprised?).   After the jars have been left to cool for 24 hours, remove the rings and wipe and dry them.  Either store them separately or put them back on loosely.

4)  Choose recipes wisely.  Use reputable resources such as the Bernardin books or website or others that you know can be trusted.  I have a canning book from Better Homes and Gardens that is excellent as well.  Any of the recipes I am sharing here have come from the Bernardin canning course I took, the BHG book I have, or from my Community Food Advisor training.  It is not advisable to use a recipe from a random blog or website, one that has been passed along to you without knowing where it came from, or recipes that were handed down to you.  Changes have been made to canning processes as more has been learned about the science of it all and it’s important to use modern recipes that reflect these changes.  Some things a reputable recipe will have:  the size of the jars you need, the amount of head space to leave in each jar, and how long to process in the water bath.

Flickr, GoodNCrazy

5)  Everything needs to be very clean – jars washed in hot soapy water, rinsed well, and sterilized for 10 minutes in boiling water.    The food must be hot and packed into hot jars (keep them in simmering water until ready to use).  Do not put the lids into boiling water (although I have seen some recipes that call for that) as you will melt away some of the rubber and the jars may not seal properly.  Hot water is enough.

6)  Be sure to use the correct pectin for the recipe.  For example, if you are making freezer jam, you need to look for the pectin that is labelled for freezer jam.  If the recipe calls for low sugar pectin, it’s important to use the pectin that’s labelled as such.  PS – If the recipe calls for lemon juice, you need to use bottled NOT fresh lemon juice.

Flickr, Southern Foodways Alliance

7)  If you don’t have an actual canner with a rack, you can safely improvise.  Use some of the canning jar lids wired together to put in the bottom of a large stock pot.  This keeps the jars raised up off the bottom of the pot and allows them to process properly and safely.  Just remember, they aren’t quite as easy to remove from the pot without the rack, so use extra caution.

8)  Remember that canning is sort of like baking – it’s a science that relies on the proper chemical reactions in order to turn out right.  Don’t go changing around the recipes you want to use willy nilly.  You saw some ice wine jelly at a local farm market and want to add some ice wine to your favourite strawberry jam recipe? You’ve now changed the chemical composition of the recipe and it may no longer turn out or be safe.  If you want to make a strawberry jam with ice wine in it, go looking for a reliable recipe for one that’s already been established and tested.  If you can’t find what you’re looking for, try contacting your local county extension office, email someone at Bernardin, or the equivalent.

Flickr, thebittenword.com

9)  After you leave the jars sitting overnight to finish sealing, you need to check them.  You need to see that the lids are now concave (when you push gently on the top, you shouldn’t be able to push down on them) and that there are no moving bubbles in the product.  If any jars didn’t seal properly, they should be put into the fridge and used as soon as possible.  The rest can be stored in a cool, dry place for up to a year.

10) DON’T forget to label your jars as to what’s inside AND with the date! Rotate the jars in your pantry/root cellar so that the oldest ones are in front and used first (don’t do what I do at the grocery store and reach for the stuff at the back!)