This recipe is found in the cookbook “Foolproof Preserving: A Guide to Small Batch Jams, Jellies, Pickles, Condiments & More” by America’s Test Kitchen. I highly recommend this cookbook to anyone who loves canning and wants recipes that are safe and that work. This a an excellent jam recipe for beginners and advanced canners alike.

Classic Strawberry Jam

Makes four 1-cup jars

3 pounds strawberries, hulled and cut into 1/2″ pieces (10 cups)

3 cups white sugar

1 1/4 cups peeled, cored, and shredded Granny Smith apple (1 large apple)

2 tbsp bottled lemon juice*

  1. Place 2 small plates in freezer to chill. Set canning rack in large pot, place four 1-cup jars in rack, and add water to cover by 1 inch. Bring to a simmer over medium heat, then turn off heat and cover to keep hot.
  2. In Dutch oven, crush strawberries with potato masher until fruit is mostly broken down. Stir in sugar, apple, and lemon juice and bring to a boil, stirring often, over medium-high heat. Once sugar is completely dissolved, boil mixture, stirring and adjusting heat as needed, until thickened and registers 217 to 220 degrees, 20 to 25 minutes. Remove pot from heat.
  3. To test consistency, place one teaspoon jam on chilled plate and freeze for 2 minutes. Drag your finger through jam on plate; jam has correct consistency when your finger leaves a distinct trail. If runny, return pot to heat and simmer for 1 to 3 minutes longer before retesting. Skim foam from surface of jam using a spoon.
  4. Place dish towel flat on counter. Using jar lifter, remove jars from pot, draining water back into pot. Place jars upside down on towel and let dry for 1 minutes. Using funnel and ladle, portion hot jam into hot jars, leaving 1/4″ headspace. Slide wooden skewer along inside of jar and drag upward to remove air bubbles.
  5. While jars are hot, wipe rims clean, add lids, and screw on rings until fingertip-tight. Do not over tighten. Return pot of water with canning rack to boil. Lower jars into water, cover, bring water back to boil, then start times. Boil 10 minutes. Turn off heat and let jars sit in pot for 5 minutes. Remove jars from pot and let cool for 24 hours. Remove rings, check for seal, and clean rims. Jars can be stored in pantry up to 1 year.

*A few people have asked if they can sub a fresh lemon for bottled lemon juice. I prefer bottled lemon juice for its consistent acidity. Acidity plays a key role in the gelling abilities of pectin. Without a consistent pH it can be difficult to predict how a jam or jelly will set. Fresh lemon juice has too much variation from lemon to lemon to consistently predict your results. Fruit is expensive and you do not want to waste a batch that won’t set up.