Mixed Berry Jam

Ingredients

Instructions

1. 1Wash 8 half-pint jars in hot soapy water or the dishwasher and keep them hot; pre-boiling the jars is not necessary since the process time below is 10 minutes or more.
2. 2Simmer the new lids in hot (not boiling) water per the manufacturer's directions and keep them warm.
3. 3Wash the screw bands in warm soapy water and set aside.
4. 4Wash and hull or stem the strawberries, raspberries, blackberries, and blueberries as needed, then crush each fruit separately with a potato masher and measure 1 cup of each to total 4 cups of mixed crushed berries.
5. 5Combine the 4 cups of mixed crushed berries with 1/4 cup bottled lemon juice and the full box of powdered pectin in a large saucepot.
6. 6Bring the mixture to a full rolling boil over high heat, stirring constantly, then add all 7 cups of sugar at once.
7. 7Return to a full rolling boil that cannot be stirred down and boil hard for exactly 1 minute, stirring constantly.
8. 8Remove from the heat and skim off any foam.
9. 9Ladle the hot jam into the hot jars, leaving 1/4 inch of headspace.
10. 10Remove air bubbles with a non-metallic spatula, wipe the rims clean, center a warm lid on each jar, and apply a band until fingertip tight.
11. 11Process in a boiling-water canner, jars covered by 1 to 2 inches of water, for 10 minutes for half-pints and 10 minutes for pints, timing from when the water returns to a full rolling boil.
12. 12Adjust for altitude: add 5 minutes at 1,001-3,000 feet, 10 minutes at 3,001-6,000 feet, 15 minutes at 6,001-8,000 feet, and 20 minutes above 8,000 feet.
13. 13Turn off the heat, wait 5 minutes, then remove jars to a towel-lined counter and let cool undisturbed for 12 to 24 hours.
14. 14Check each seal (concave, firm lid), remove the bands, wipe the jars, and label with contents and date.
15. 15Store in a cool, dark place up to 1 year for best quality; refrigerate after opening and use within about 3 weeks.
16. 16Do not alter the total fruit, sugar, lemon juice, or pectin proportions, since this ratio determines both safety and set.