Citric acid is a natural preservative used as a food additive. An essential ingredient in home canning, citric acid is used to maintain a safe pH level in the canning of fruit and vegetables. Although many fruits contain a certain level of acid, it is not nearly enough to kill all harmful bacteria. Citric acid will prevent the formation of bacteria and spores that can cause food poisoning and keep your fruit looking fresh by preventing the occurrence of brown spots.
Place your jars in boiling water for five minutes. Add the lids to the boiling water and allow everything to boil for another five minutes. Boiling will sanitize them and reduce the risk of food contamination. Remove the jars and lids and set them aside.
Wash your fruit in cold water. Place the fruit in boiling water for 20 to 45 seconds. Remove the fruit and place it into a bowl of cold ice water. You can now peel the fruit with ease, sliding the skin right off.
Cut your fruit, removing any mushy or brown areas. Sprinkle your citric acid over the fruit to prevent any color change.
Place your canning liquid into a pot, and when it has almost reached a boil, add your fruit. You can use a sugar syrup, fruit juice or even water for canning. Allow it to cook for five minutes. This method will help reduce air bubbles in your final product.
Pour your fruit into the sanitized jars, leaving an inch of space at the top. Use a jar funnel to prevent spills. Add your canning liquid to the jar, leaving 1/2 inch of space at the top. You must cover the fruit in its entirety.
Run a spatula or knife along the edge of the fruit and the jar. Press it inwards on the fruit to remove any trapped air.
Add your citric acid, 1/4 tsp. for a pint and 1/2 tsp. for a quart. Add your lids and screw bands to the jars and tighten. Process the jars in a water bath. Cover them with an inch of water and boil for 20 minutes. Lift the jars out of the water with tongs and set them aside in a safe place to cool down.
Check the lid, once the jars have cooled down, to see if they have sealed properly. If the button in the middle pops up, making a noise, then it has not been sealed. You can repeat the hot water bath to process the jar again.
Feel free to add sugar when you add the acid if you want to offset the acidic taste. Store your jars in a cool, dark place for a longer shelf life.