I recall a phone call I received a few years ago during the summer. My caller was quite upset because several jars of her home-canned raspberry jam had literally flipped their lids, spewing sticky raspberry jam throughout her pantry.
Before she called, she had been scrubbing the jam from her pantry walls. One of the jars popped open while we visited on the phone. She was not happy.
She asked why this had happened and how to prevent it in the future. As we visited, I learned that she had used a recipe formulation that was still valid, and she was using two-piece lids, not paraffin wax, to seal the jars. This was consistent with what we recommend.
We figured out the likely reason for the mess in her pantry. Turns out, the recipe she was using did not recommend boiling the filled jars of jam in a water-bath canner for a specified time (usually five minutes).
Her old recipe called for inverting the jars. However, the U.S. Department of Agriculture has recommended a boiling-water bath process for jams and jellies for many years. Becausw her lids had sealed, she thought she would be enjoying homemade jam in the winter. Instead, she was doing a lot more cleaning than she had planned that day.
I advised my caller to wear rubber gloves and use a disinfectant during the cleanup because we were not exactly sure what organism was responsible. I didn’t hear from her in subsequent years, so I hope she didn’t give up on making jellies and jams.
Stay Out of a “Jam” With Current Canning Recommendations
If microorganisms are not deactivated by sufficient heat for the right length of time, some can produce gas in an airtight container. Some organisms can produce enough gas to blow the lids off jars. Other microorganisms can produce deadly toxins if they are not killed through proper processing.
The boiling-water bath processing of jams and jellies also prevents mold growth (until the jar is opened) and ensures a tight seal.
To learn more about making jam and jelly at home, contact your local Extension office or check out the materials on www.ag.ndsu.edu/pubs/preservation.html.
On this site, you will find free how-to publications titled “Jellies, Jams, Spreads,” “Jams and Jellies from Native (Wild) Fruits” and “Jams and Jellies from North Dakota Fruits.” You also will find information about freezing food, making salsa and pickles, and pressure canning low-acid foods.
Fresh bread or muffins with homemade jam or jelly is hard to beat. Here’s a popular raspberry jam recipe to try.
5 c. raspberries and juice
7 c. sugar
1 box powdered pectin
Half-fill water-bath canner with hot water; place it on the stove and let it come to a boil while preparing jam.
Crush the raspberries with a potato masher. Mix the raspberries and pectin and heat to boiling, stirring constantly.
Add the sugar all at once and stir until dissolved. Continue stirring gently until the mixture comes to a full rolling boil that cannot be stirred down. Start timing for one minute and stir constantly while it continues to boil.
Remove from heat. Skim any foam from the jam, and carefully ladle the jam into clean jars using a canning funnel. Fill jars to within 1/4 inch of the rim. Wipe the rim with a clean, damp cloth. Quickly apply the lid and fasten with a ring. Process for 10 minutes (when water begins to boil again, start timing) in a boiling-water bath.
Makes eight half-pints. Each 1-tablespoon serving has about 45 calories, 0 grams (g) of fat, 0 g of protein, 12 g of carbohydrate, 0 g of fiber and 0 milligrams of sodium.