Homemade Pectin Strawberry Jam

In a saucepan, combine chopped apples, water, and chopped lemon. Bring to a boil over high heat, then reduce heat to medium. Cook, stirring occasionally, until fruit is soft and collapsed (about 30 minutes). Remove from heat.

Strain the apple mixture through a fine-mesh sieve into a bowl to separate liquid from pulp and seeds. Press with a wooden spoon or spatula to extract as much liquid as possible. Discard pulp and seeds. You should have about 1 1/2 cups pectin puree.

In a food processor, pulse hulled strawberries until puréed (about 1 minute). Transfer to a saucepan. Add pectin puree and 1 cup sugar; stir well. Bring to a simmer over medium-high heat. Reduce heat to medium; simmer for about 15 minutes.

Skim off any foam that forms on the surface. Adjust heat if necessary so the mixture maintains a simmer without boiling over. Stir in remaining 1 1/4 cups sugar.

Cook and stir until mixture reaches 220°F (105°C), which should take about 50-60 minutes. Remove from heat; whisk in lemon juice.

Ladle jam into sterilized canning jars while still hot. Allow to cool at room temperature without covers. Then, cover and refrigerate for 1-2 days to let the sugar and pectin set before serving.