Koopman Lumber Canning

Project Book: Canning Fruits and Vegetables

If you’ve had a successful gardening season, you will end up with a bounty of fruits and vegetables at harvest time. Even though much of it will be eaten fresh or baked into meals, snacks, and desserts, you are likely to end up with more fruits and vegetables that you won’t immediately use. This is where canning comes in.

Canning is a terrific way to store your fruits and vegetables while they are fresh and in season. It also helps you prolong the harvest through the cold winter months. Canning is a precision form of cooking. By applying heat and pressure to food in closed glass jars, it is kept from spoiling and removes air from the jar to create a tight, secure seal. Canning will save you money on your grocery bill (especially when local fruits and vegetables are out of season), is eco-friendly, cuts down waste, and guarantees your produce will be free of BPA and additives.

It is best to can your produce immediately after it is harvested to ensure the highest vitamin and nutrient concentration. The longer a fresh piece of produce sits, the more vitamins it loses.

Blog Series: Canning Fruits and Vegetables

Difficulty: Medium
Time: 2 hours

Even though canning uses ordinary kitchen skills, you must observe instructions precisely to ensure that the food is sterilized and safe. This one time when you definitely shouldn’t improvise.  

It’s relatively easy to can most fruits and vegetables, but certain kinds of produce may require a different method. For helpful tips on how to can fruit and vegetables to best preserve your garden’s bounty, visit the website of the National Center for Home Food Preservation.

Finally, make sure that you use jars specifically designed for canning. Avoid mayo jars and others kinds of glass containers because they may not hold up to the pressure when they’re being processed.

Step 1: Sterilize Jars and Wash Produce

Canning jars need to be sterilized before even a single piece of produce comes into contact with them. Begin by washing the lids and jars in soapy, hot water. Then moving them to a bath of boiling water for 10 minutes to sterilize them.

After 10 minutes, remove the jars from water bath but keep the lids in the hot water until you’re actually ready to use them. This will ensure that they don’t come into contact with anything before you seal the jars. It’s incredibly important that things be as sterile as possible at all points during this process!

Gather the produce that you are going to can and wash it thoroughly in cold water.

STEP 2: Slice, Dice, and Pickle it Nice

canning-step-2Now it’s time to cut up your produce into pieces as specified your given recipe. Remember to remove any cores, pits or other parts that you don’t want to, or shouldn’t, eat!

Some fruits will need to be peeled, depending on what type you’re using. Some fruits, like peaches, can be “slipped,” which means to slide off the fruit’s skin before canning. Briefly dip the fruit in boiling water until the skin splits open. Then move the fruit to cool water and the skin will easily slip off.

To prevent the produce from discoloring once it is canned, don’t use any bowls, cookware or utensils made of copper, aluminum, iron or chipped enamel during preparation. If you have hard water, use bottled water to prepare the food.

To prevent browning of fruits such as peaches and pears, put them into an ascorbic acid solution after they’ve been sliced.

Step 3: Fill & Cap Your Jars

canning step 3Put your produce into your canning jars using a wide-neck funnel. During the boiling process to follow, produce expands. Make sure to leave adequate at the top of the jars to prevent leaking.

Unless you are canning jams, the next step is to pour the liquid into the canning jars to submerge the produce. You can use either boiling water, pickling solution (for vegetables) or sweet syrup or white grape juice (for fruit). Tomatoes should have a citric acid – such as lemon juice – added to them to keep their pH level above 4.6.

Always follow the head space requirements specified in whichever recipe you’re following and be sure to measure carefully. Too much headspace can make it difficult to properly seal the canning jars.

Using a soft plastic spatula, push down the produce to fully submerge it under the liquid. Then run the spatula along the inside of the jar to eliminate air bubbles. Finally, clean off the jar’s rims with a damp paper towel.

Close each jar using a sterilized two-part lid, making sure that they’re tight and secure without over-tightening them. If the lids are on too tight, air can’t escape and create the seal necessary to keep your food preserved and free of harmful bacteria.

Step 4: Process Your Jars

Canning Water Bath image

There are two popular canning techniques; Water Bath and Pressure Canning. Having an understanding of which method to use is crucial.

Water Bath

The Water Bath technique is ideal for high-acid foods. If you’re canning fruits, fruit juices, jams, jellies, salsas, pickles, vinegar, and condiments, this is the method to use as it does not require as much time to process as pressure canning.

Fill the pot halfway with water, or enough to reach about 1-2″ above the jars once they’ve been loaded. Preheat the water to 180° F for hot packed produce or 140° F for raw packed produce. Insert the canning rack and capped jars. Cover the canner and bring the water to a steady, gentle boil, which needs to be maintained through the required processing time.

Helpful Tip: Because water boils at lower temperatures at higher altitudes. You can check your elevation with the U.S. Geological Survey. The National Center for Home Food Preservation also offers Processing Time Tables.

Canning Pressure Canning imagePressure Canning

The Pressure Canning technique is the one to use when preserving non-acidic produce, meats, poultry, and seafood. We use this because safety is essential when it comes to these food items and foodborne bacteria. The Pressure Canning method heats the contents of your jars to 240° F.

Also, If you’re mixing high acid foods with low-acid foods, you must use the pressure canning method.

Follow the manufacturer’s directions to determine the amount of water needed in the bottom of the pressure canner before the jars are added. Use a jar lifter or tongs to place the jars into the hot water inside the canner. Then lock the canner lid securely. Turn up the heat to its highest position and allow steam to vent for approximately 10 minutes, then completely seal the canner and allow pressure to build inside.

Be sure to monitor the amount of pressure closely. Once the canner has reached the required pressure as specified by the manufacturer, maintain it for the time directed (usually about 20 minutes). Then turn off the heat and let the canner cool down. When the pressure gauge has gone all the way down to zero, let the steam inside escape through the vent.

Safety First: When removing the pressure canner’s lid, tilt it away from your face or the hot steam inside may cause injury.



testing_jar_sealsUse jar lifters to remove the jars. Place them on a wooden board about 1″ apart to cool.

After allowing 24 hours for them to cool, check the lids to make sure that the jars have sealed properly. Push down on each metal lid; it should be indented not give any spring back. If any jar is not sealed, put it in the refrigerator and be sure to eat them as soon as you would fresh produce.



bell-dissolvable-canning-jar-labels-60ct-1440010734Label your jars with contents and the date with something at home, or even something that Koopman carries, like Ball’s canning labels. By using them, you don’t have to write directly on the lid with a permanent marker. They are designed to firmly adhere to the glass sides of jars and/or the metal lids. And once you’ve used all of a jar’s contents, the labels dissolve quickly in water while washing by hand or the dishwasher.

Once your jars are labeled, find a cool, dark, dry place to store them. This will help to preserve vitamin content and discourage lid corrosion. Make sure to avoid areas near furnace ducts, hot water pipes, stoves, hot water heaters or furnaces. Avoid uninsulated areas of your home that may be exposed to extreme hot and cold temperatures that would not be appropriate for can food storage.

How you store canned food is almost as important as where. Placing filled jars in cupboards or boxes protects them from light. Wrapping the jars in newspapers and protecting the boxes with blankets can help protect them from freezing.

Wrap Up

Home canning is a safe and economical way to put delicious, nutritious food on your table at every meal. Since they don’t expire quickly, you won’t waste money canning fruits and veggies which can happen with store-bought produce. Canned vegetables save food preparation time because they are already cut, sliced, peeled and pre-cooked, requiring only reheating.

For everything you need to get your canning project off to a good start, come by and see us at Koopman. Visit Koopmanlumber.com and find the store nearest you!