How to Can Food: A Step by Step Guide

How to can food

Phrases like “living off the grid” are often muttered in rural parts of beautiful New England. Everyone has advice of how best to preserve vegetables to make eating home-grown food during the frigid winter months possible. Freezing, drying, maintaining a root cellar and canning are all common practices throughout New England’s many rural communities. During my visit to the region I got a lesson in how to can food – apple sauce and pickled beets.


1) Glass canning jars: These will include lids, rubber rings (if you are using old-style glass lids) and bands, all which are vital to making the seal that is needed in order to safely preserve food. Ordinary glass jars are not sturdy enough to undergo the canning process so be sure to buy jars specifically made for canning to avoid ending up with a pot full of broken glass. The most prevalent brands are Ball and Kerr in the US, Bernadin in Canada and Weck, which have glass lids, in Europe. You can purchase various sized canning jars at any local appliance store or their online equivalent.

Canning Food - Use Mason Jars

Mason jars are needed

2) A canner: There are two types of canner, a pressure canner and a boiling water canner, otherwise known as a waterbath canner. Both come in various sizes but are used for different food items. While a pressure canner is used for low-acid foods, such as potatoes, broccoli and most vegetables, a waterbath canner is used for high-acid foods, such as tomatoes (and most fruits) and pickled vegetables.

In my lesson we used a waterbath canner.

NOTE: Canning is a kind of sterilization process.  It is important that your equipment, hands, and working area are very clean.  Thoroughly clean the canning jars, using a brush and hot water.


When canning food it is important to consider the acidity content of each item. The Ball Blue Book: Guide to Preserving can be very helpful, especially for beginners, as it gives recipes for fruits, veggies, relishes, jams and much more. Following this trusted information relieves the worry about the correct measurements of ingredients and assures the right level of acidity.

During my lesson we began by going out to the garden only feet away from the kitchen where we were to do the food preparation and canning. We pulled fresh beets from the ground and then picked fresh apples from the trees next to the garden.  We cleaned and cut the beets and apples into cubes to prepare the picked beets and apples sauce.

Canning Food - preparing beets and apples

Preparing Beets and Apples


There are basically two parts to canning food: making the food and canning it. Be sure to measure out how much food you will be making and decide which sized jars are best for your food item. In choosing the size, consider how much of your food item you will consume in one sitting. If you are likely to eat it all in one go, such as tomato sauce, then a larger container of it might work well for you. If however, it is something to nibble on, such as the famous dilly beans in Vermont, consider using smaller jars.

Once your food has been prepared, it is now time to can. To do this follow these steps:

1) Add the food to your jar and be sure to giggle the jar a bit to ensure that your food settles.

How to can food - Filling jars

Filling jars

2) Measure your head space:  head space is the unfilled space above the food in the jar and below its’ lid. The proper amount of head space varies so pay attention to the amount of head space each canning recipe calls for. For tomatoes, for example, the head space is generally 1/2 inch. Using a pressure canner requires more of a head space. The purpose of the head space is two-fold: 1) to allow the expansion of food during the hot canning process and 2) to form the vacuum in the cooled jars needed for sealing. If you do not use enough head space, you will not obtain the proper seal, causing you to have to refrigerate your item, completely defeating the whole canning process.

3) Release air bubbles: It is important to ensure that there are no air bubbles in your product. Use a spoon, spatula or knife to allow any hiding air bubbles to escape. At this point, you may have to add more prepared food or liquid to the jar in order to maintain the proper head space.

4) Seal your jars: With a dry cloth wipe down the jar rims before placing the lids on and screwing in the bands. Be sure not to screw the bands on too tightly.

5) Heat your canner: After filling your canner with one-half to two-thirds water, heat until boiling. It is important that the water remain consistently at a high temperature so it was recommended that you allow the water to come to a rolling boil before proceeding to the next step.

6) Add your jars to the canner: Using a jar lifter, lower each jar into the hot canner and close the lid of the canner to maintain the heat. The amount of time you leave the jars in the canner depends entirely on what food item you are making so be sure to consult the recipe.

NOTE: When you first put the jars in the canner, the temperature will drop to below boiling.  Wait till the water boils again, and start the timing then.  The water needs to be boiling for the entire time.

Canning Food - Use Jar Lifter

Use a jar lifter!

7) Remove the jars from the canner: Using the jar lifter remove the jars and place them on a flat surface covered with a kitchen towel for cooling, which takes up to 24 hours.

Canning Food - Water Bath

Those jars need a bath!

8) Test your seals: In order to ensure that you have a vacuum inside the jar, push on the center of the lid. If it is indented and doesn’t pop up, you have a successful seal. If a lid does not indent after 24 hours, you do not have a successful seal and should refer to the Warning section of this post.  At that point, you can re-process them, or you can eat them as you would un-canned food products.

9) Label your product: After placing a sticker on the side of your cooled jar, be sure to label your canned good with its contents and canning date. Store is a cool, dry and dark place.

Canning Food - Finished Product

Finished product!

10) Final Test: A second and final seal test of your canned food comes when, later on, you open the jars to eat the food.  You should hear the rush of air when a vacuum seal is broken.  Also watch for any mold that may have formed at the top of the food or underneath the lid. If you see mold, do not consume any part of the jar’s contents.


It can be very dangerous if you eat food that was not sealed properly. It is therefore important to leave enough head space and check the seals of each jar before storing. If a jar has not been sealed properly, discard it. On the other hand, leaving too much head space could lead to spoilage of your product as there is too much air in the jar.

Do you have any more canning tips?

8 thoughts on “How to Can Food: A Step by Step Guide

  1. Helga Leidel

    Well written thanks. We always did lots of preserving and I have a water bath pot with built in thermometer hole and lots of glasses. You could have them all if living closer, as for Opa and I and no garden it’s not worth my while to do it any longer.

    xo Oma 🙂

    1. Mindy & Ligeia

      Canning really does seem like a great way to preserve fresh food during the long winter months in the colder areas of the world. We look forward to doing that when we eventually make our new home in New England, most likely Vermont. 🙂 And then we might just take you up on that water bath pot offer.

  2. Patti

    We’ve never lived off the grid but at one point we did a lot of gardening and canning, using jars and water baths. It’s a “lot” of work but the efforts are well-worth it. There is a lot of pride in canning as well, for many people, I think it is an art.

    1. Mindy & Ligeia

      That’s a good point that you don’t have to live “off the grid” in order to reap the benefits of canning food. And I did notice a certain amount of pride regarding canning while I visited New England. I think neighbors and friends must discuss various canning techniques and recipes. Can’t wait to try canning myself. 🙂

  3. Tara Collins

    Great post Ligeia!

    My Mum and I recently took a Canning 101 class that was offered through a local organic farm here in Toronto. It was great to learn the waterbath technique of canning. I’m excited to can my own beets and make zuchini relish at some point in the near future!!

  4. Nicole Rossetti le Strange

    You really need to have a ‘like’ button for people’s responses! 🙂

    I also haven’t lived completely off-grid but for 10 years when my kids were young, we were around 85% self-sufficient with regard to food. If I’d had space to grow wheat to grind into flour, I would have done! Ha ha!

    The only preserving I’ve done has been chutneys, jams, curds, and pickled onions. And until we came to live in Thailand, I always made my own yoghurt, and sometimes soft cheese. I’ve never tried canning though… I think that like most home crafts, it’s a much bigger thing in the US than in the UK. It makes so much sense if you have a surfeit of produce.

    Something I really miss is my home-grown food – it’s not just that it tastes better (no really, it does!) but there’s something deeply satisfying about working with the land in order to produce such wondrous bounty for the table. I love it!

    1. Mindy & Ligeia

      Hi Nicole,
      I completely agree about “working with the land”. There’s just something about putting my hands in the earth that is so satisfying. I believe that growing things is the biggest magic trick of them all! I am still amazing and SO excited when I see that first bit of green poking through the ground after simply putting a small seed in the ground and giving it some water – so much more magical than pulling a rabbit out of a hat!

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