While canning jellies and jams are one of my favorite activities, it is important to understand how to do so correctly. There are a lot of misunderstandings about what is safe for canning. Today, we are going to look at why acidity matters for canning.
The Role of Acidity in Canning
I get a lot of questions from friends and family about canning. Many people don’t understand the role of acid in canning. The fact is that you cannot can every single fruit out there if you plan to use a water bath canner.
To be considered safe, the fruit you selected must have a pH scale of 4.6 or lower. The lower the number, the more acidic! Why is acid important? Botulism cannot grow and thrive in an acidic environment. To safely can your fruits in a water bath canner, the acid must be present.
Foods that are lower in acids, such as meat or vegetables, must be canned in a pressure canner. Their pH level is higher than 4.6. A pressure canner heats the food to a higher pressure, ensuring all bacteria spores are killed, including botulism.
When canning jellies and jams, acid plays another role. It helps to set and gel. If you want to have an enjoyable, safe jelly or jam, you need acid!
What Fruits Aren’t Safe?
Luckily, most fruits are acidic, such as apples and strawberries. The fruits you cannot water bath safely due to low acid are bananas, figs, melons, dates, and papayas.
Tomatoes, which comes to a surprise for many people, can be borderline. They are considered a low-high acid food. If you don’t want to can your tomatoes in a pressure canner, try adding a form of acid, listed before.
Can You Increase the Acidity?
Sometimes, fruits will vary in acidity. For example, an overripe apple has less acid than an under-ripe one! There are a few ways you can fix your pH level.
· Add some under ripe fruit to your recipe. For example, if you are making applesauce, add some under ripe green apples. If you are making strawberry jam, add some under ripe strawberries, which also contains more natural pectin!
· Try adding 1 TBSP of lemon juice for each cup of fruit. If you are making strawberry jam with overripe strawberries, you would need 4 TBSP of lemon juice for 4 cups of strawberries.
If you are curious about the pH level of your selected fruit, click here for my free chart! It contains the pH level of most fruits.
[…] are dozens of foods that you cannot safely can in a water bath canner. The difference comes from the acid in the food. The higher amount of acid, the less likely botulism can survive. Foods that have a pH level of 4.6 […]