Preserving your Harvest

Late summer is full of many things: back to school shopping, getting the most out of those last few summer nights, and in my house, CANNING. My grams had a large "victory garden" and canned a large portion of what they grew to use during the leaner winter months and my mom later followed suit. So it seems only right to be canning the (literal) fruits of our labors when they are at the peak of ripeness between August and October, depending on the crop. It also keeps heaps of fresh fruit and veggies from going bad, which is great for my wallet, since I took most of the summer off of work.

My co-worker Miriam has a beautiful Green Gage plum tree in her yard and got a giant crop this year and I was only too happy to take a bag of them off of her hands to make Plum Jam. But before we get into the how-to's, let's talk about the process and theory behind canning.

Canning is really one step beyond cooking. It is a method that applies heat to food in a closed glass home canning jar to stop the natural spoilage that would otherwise take place, and removes air from the jar to create a seal.
— Ball Canning via

There are two at-home methods for canning, water-bath and pressure canning. I do not own a pressure canner (but would like one...feel free to remedy this situation) so I will be demonstrating the water-bath method.

The Water-Bath Method

In water-bath canning you will be working exclusively with foods that are high in acidity. High-acid-foods are easy to preserve and include fruits, fruit juices, jams, jellies and other fruit spreads, salsas, tomatoes with added acid, pickles, relishes, chutneys, sauces, vinegars and condiments. The high acidity ensures that bacteria will not grow in your food and destroy all of your hard work. In order to can low-acidity foods (vegetables, meat, poultry, seafood) you need a pressure canner which can achieve the appropriate temperature (240F) to kill all bacteria.


  • Tested preserving recipe-- this is important to ensure the correct ph for canning, it's possible to do your own recipe but botulism is no picnic so I opt for tested recipes from the Ball Canning and Preserving Guide. Heirloom recipes are super special to have but I use them only for things I intend to freeze, rather than can.
  • Water bath canner (or a large, deep pot with a lid) and a canning rack
  • Second large pot with lid-- to sterilize/heat jars
  • Glass preserving jars, lids and bands (always start with new lids, you can re-use the bands and jars).
  • Jar lifter (or tongs)-- not a necessity but they come in REAL handy when the jars are super hot
  • Common kitchen utensils, such as wooden spoon, ladle, and funnel. Also many dishtowels. I am a big canning mess-maker.
  • Fresh produce
My home canning set-up: the recipe, water bath canner, jar lifter, and second pot for heating jars.

My home canning set-up: the recipe, water bath canner, jar lifter, and second pot for heating jars.

Preparing the Jars

1. Check jars, lids and bands. Jars with nicks, cracks, uneven rims or sharp edges may prevent sealing or cause jar breakage. The underside of lids should not have scratches or uneven or incomplete sealing compound as this may prevent sealing. Bands should fit on jars. Wash jars, lids and bands in hot, soapy water. Rinse well. Dry bands.

2. Fill a large saucepan or stockpot half-way with water. Place jars in water (filling jars with water from the saucepan will prevent flotation). Bring to a simmer over medium heat. Keep jars hot until ready for use. You may also use a dishwasher to wash and heat jars, a good idea if you are doing a LOT of canning. Keeping jars hot prevents them from breaking when hot food is added. Leave lids and bands at room temperature for easy handling.

3. Prepare boiling water bath canner by filling half-full with water and keep water at a simmer (covered with the rack in place) until jars are ready. You don’t necessarily need to buy a water-bath canner if you don’t already have one at home. You may already have a pot large enough to double as a canner. A water bath canner is simply a large, deep saucepot equipped with a lid and a rack. The pot must be large enough to fully surround and immerse the jars in water by 1 to 2 inches and allow for the water to boil rapidly with the lid on. If you don’t have a rack designed for home preserving, use a cake cooling rack or extra bands tied together to cover the bottom of the pot. This might be a good alternative for first-time canners until you decide to invest in canning gear.  

The Recipe

As I said before, I tend only to use tested recipes found in the Ball Blue Book Guide to Preserving or from another trusted source. After putting in all the work growing, harvesting and putting up your produce, it is truly horrible to have it all go to waste because of a bad recipe. I will divert slightly when it comes to some spices and the amount of sugar because I am not overly fond of super sugary jams, purees or spreads. 

For the plum jam, I used the Ball Blue Book recipe:

  • 5c coarsely chopped plums
  • 3c sugar
  • 3/4c water

Combine water, sugar and plums in saucepan and slowly bring to a boil, stirring until sugar dissolves. Cook rapidly to the gelling point; approximately 220 degrees F at sea-level or when the jam "rounds" up on a spoon. As the jam thickens, stir frequently to prevent sticking. Once gelled, remove from heat and skim off foam if necessary. Ladle into hot jars, leaving 1/4" of space between the jam and the top of the jar, also called headspace. Process for 15 minutes in boiling-water canner. Recipe yields about 3 pints. I used two half-pints (for me) and six 4oz jars since they are a better size for gift-giving.

Filling and Processing

Once the recipe is ready, it is time to fill and process the jars!

1. Remove hot jar from water, using jar lifter or tongs, emptying water inside jar. Fill jars one at a time with prepared food using a funnel and ladle, leaving space recommended in recipe. Remove air bubbles, if stated in recipe, by sliding a rubber spatula between the jar and food to release trapped air and ensure proper headspace during processing.

2. Clean jar rim and threads of jar using a clean, damp cloth to remove any food residue. Center lid on jar allowing sealing compound to come in contact with the jar rim, apply band and adjust until fit is fingertip tight.

3. Place filled jars in canner until recipe is used or canner is full.

4. Lower rack with jars into water. Make sure water covers jars by 1 to 2 inches. If not, I will typically pour the already-hot water from the jar heating pot into the canner.

5. Place lid on water bath canner and bring water to a full rolling boil. Once the water is boiling, begin processing time per the recipe.

Now we wait... I hate waiting.

6. When processing is complete, turn off the heat and remove the canner lid, leaving the jars to stand for 5 minutes. Remove jars from canner and set upright on a towel to prevent jar breakage that can occur from temperature differences. Leave jars undisturbed for 12 to 24 hours. Bands should not be retightened as this may interfere with the sealing process.

MORE waiting... ugh.

7. Check that jar lids have a good seal. Lids should not flex up and down when center is pressed. Remove bands and try to lift lids off with your fingertips. If the lid cannot be lifted off, the lid has a good seal. If a lid does not seal within 24 hours, the product can be immediately reprocessed or refrigerated. Clean mason jars and lids with a damp towel. Label with contents & date, then store in a cool, dry, dark place for typically up to 1 year.


My pictures of the finished jam didn't turn out so behold Brandied Pears!

My pictures of the finished jam didn't turn out so behold Brandied Pears!


I hope you will all feel confident enough to try you own hand at canning, it is fun and very satisfying even if it does turn your kitchen into a sauna. Keep me posted on your own beta projects, canning or otherwise with #BettyBetaTester. Despite being back at work, there is plenty more coming your way soon from Betty HQ, so stay tuned!