Strawberry Jam Recipe (Classic Water Bath Canning Method)

Name: Strawberry Jam Recipe (Classic Water Bath Canning Method)
Prep time: 30 min
Cook time: 25 min
Total time: 55 min
Yield: 80 servings
Ingredients: 2 lb strawberries, hulled and crushed; 4 cups granulated sugar; 1/4 cup bottled lemon juice; 1 box (1.75 oz) powdered fruit pectin

Powdered pectin sets quickly at a full rolling boil, so the fruit only needs a few minutes of hard cooking, which preserves bright strawberry color and flavor. The added lemon juice brings the mixture to a safe, consistent acidity for water bath processing, and a full boiling water bath after filling creates the vacuum seal that makes the jam shelf-stable.

Prep: 30 min
Cook: 25 min
Total: 55 min
Servings: 80

Ingredients

Servings80

2 lb strawberries, hulled and crushed
4 cups granulated sugar
1/4 cup bottled lemon juice
1 box (1.75 oz) powdered fruit pectin

Nutrition per serving

Calories: 43
Protein: 0g
Carbs: 11g
Fat: 0g

Based on the recipe as written, one serving. Recalculates if you swap an ingredient above. An estimate only, exact values depend on the specific ingredients used.

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Instructions

1Wash 5 half-pint canning jars, lids, and bands in hot soapy water. Keep jars hot in a simmering water bath canner or a 200°F (95°C) oven until ready to fill.
2Hull the strawberries and crush them with a potato masher in a large bowl, leaving some small chunks for texture, until you have about 4 cups of crushed fruit.
3In a wide, heavy-bottomed pot, stir together the crushed strawberries, lemon juice, and powdered pectin. Bring to a full rolling boil over high heat, stirring constantly, one that doesn't stop bubbling when stirred.
4Add the sugar all at once and return the mixture to a full rolling boil, stirring constantly. Boil hard for exactly 1 minute, then remove from the heat.
5Skim off any foam from the surface with a metal spoon.
6Ladle the hot jam into the hot jars, leaving 1/4 inch of headspace at the top of each jar.
7Wipe the jar rims clean with a damp cloth, center a lid on each, and screw on a band until fingertip-tight.
8Lower the filled jars into a boiling water bath canner, making sure they're covered by at least 1 inch of water. Process for 10 minutes (adjust for altitude), then turn off the heat and let the jars sit in the water for 5 minutes.
9Remove the jars with a jar lifter and set them on a towel, undisturbed, for 12 to 24 hours. Check that each lid has sealed (it should be concave and not flex when pressed) before storing.

Tips & variations

At altitudes above 1,000 feet, add 5 minutes to the processing time for every additional 1,000 feet of elevation.
To test for set before filling jars, chill a small plate in the freezer, drop a spoonful of hot jam onto it, and push it with a finger after a minute; if it wrinkles rather than pooling, it's set.
Low or no-sugar pectin can replace regular pectin, but follow the ratios on that specific pectin's package insert since they're formulated differently.
Frozen strawberries work in place of fresh; thaw them fully and don't drain off the juice, since it's part of the measured fruit volume.

Storage & reheating

Properly sealed jars store in a cool, dark pantry for up to 1 year. Once opened, refrigerate and use within 3 weeks. If a lid doesn't seal within 24 hours, refrigerate that jar and use the jam within a month, or reprocess it with a new lid within 24 hours.

Tips from the Tulo kitchen

Crushing the strawberries by hand with a masher instead of pureeing them in a blender keeps small fruit chunks intact, which makes for a jam that looks and tastes more like whole fruit.
Warming the sugar slightly in a low oven before adding it helps the mixture return to a boil faster and shortens the total cooking time.

FAQ

Why didn't my jam set?

The most common causes are not measuring the fruit and sugar precisely, not reaching a true full rolling boil before adding sugar, or not boiling hard for the full minute after the sugar goes in; pectin needs both heat and acidity to gel properly.

Can I use fresh lemon juice instead of bottled?

Bottled lemon juice is recommended for canning because its acidity is standardized, while fresh lemons vary in acidity from fruit to fruit, which matters for a safe, shelf-stable seal.

How do I know a jar sealed properly?

After the jars cool for 12 to 24 hours, press the center of each lid; it should be concave and not flex or pop. You can also remove the band and try lifting the jar by the lid alone; a sealed lid won't budge.

Can this recipe be doubled?

It's best to make only one batch of jam at a time using this method; doubling a batch of pectin jam often prevents it from reaching a proper set because the larger volume takes longer to return to a boil.