Prepare boiling water canner. Heat jars in simmering water until ready for use. Do not boil. Wash lids in warm soapy water and set bands aside.

Combine strawberries and lemon juice in a 6- or 8-quart saucepan. Gradually stir in pectin. Bring mixture to a full rolling boil that cannot be stirred down, over high heat, stirring constantly.

Add entire measure of sugar, stirring to dissolve. Return mixture to a full rolling boil. Boil hard 1 minute, stirring constantly. Remove from heat. Skim foam if necessary.

Ladle hot jam into a hot jar leaving a ¼ inch headspace. Remove air bubbles. Wipe jar rim. Center lid on jar and apply band, adjust to fingertip tight. Place jar in boiling water canner. Repeat until all jars are filled.

Process jars 10 minutes, adjusting for altitude. Turn off heat, remove lid, let jars stand 5 minutes. Remove jars and cool 12-24 hours. Check lids for seal, they should not flex when center is pressed.

Delicious Classic Strawberry Jam Variations

Vanilla Strawberry Jam:

Add half a vanilla bean, split in half lengthwise, to the crushed strawberries. Cook as directed and remove vanilla bean before ladling jam into jars. The resulting jam will be enhanced with subtle yet distinct vanilla overtones.

Strawberry Balsamic Jam:

Reduce the lemon juice to 1 tbsp and add 3 tbsp good-quality balsamic vinegar. Balsamic vinegar accents the strawberry flavor and gives the jam a robust taste.

Lemony Strawberry Jam:

Add the grated zest of 1 large lemon to the crushed strawberries.

Black Pepper Strawberry Jam:

Stir 1/2 tsp freshly ground black pepper into the cooked jam just before ladling it into the jars. Pepper accents and compliments strawberries' sweet flavor. Be sure to use freshly ground pepper, which delivers a fresher-quality flavor.