1lbfresh or frozen strawberries,hulled, washed and chopped into 1/2 inch pieces
½lbfresh or frozen rhubarb,chopped into 1/2 inch pieces
1small lemon,zested and juiced (about 2 tbsp lemon juice)
3tbspclassic powdered pectin
1 ½ - 2cupsgranulated sugar,adjust for desired tartness/sweetness
½tspunsalted butter
Instructions
First, make sure your jam jars, lids and rings are clean and sterilized. You can sterilize them in the dishwasher, or by boiling them for a few minutes in a large stock pot.
In a large stock pot, combine the strawberries, rhubarb, lemon juice and zest. Simmer for about 15-20 minutes over medium heat, until the rhubarb is softened and beginning to break down. Mash the fruit slightly, or leave it chunky, whichever you like.
Sprinkle the pectin over the fruit and stir it in. Increase heat to medium/high and stir constantly (while wearing oven mitts to protect against splatter burns), and bring to a boil.
Dump all the sugar in at once. Use 1 1/2 cups of sugar for a more tart jam, or 2 cups for a sweeter jam. Continue stirring constantly to return to a vigorous boil that can’t be stirred down. Boil hard for 1 minute.
Remove from the heat and stir in the butter (the fat helps to reduce any foaminess).
Immediately ladle the jam into hot, sterilized jars, leaving a 1/4 inch gap at the top (called "head space") to allow for expansion. Wipe the rims of the jars with a clean damp cloth. Center the lids on the jars, and screw on the lids "fingertip tight".
Jam stored in the refrigerator should be consumed within 1-2 months.
Notes
Preserving and Storing Homemade Jam:
Refrigerate for Immediate Consumption: For jam that you'll be consuming within 1-2 months, you can simply store the jars in the refrigerator, and the sugar helps to keep the jam from spoiling.
Can in a Water Bath for Longer Preservation: If you're planning on storing the jam in your pantry or giving jars away as gifts, you should process the hot jars of jam in a water bath according to standard canning procedures to seal the lids. Simply turning the hot jars upside down will not properly seal the lids and could lead to bacterial contamination.
Freeze the Jam: An easy way to store jam for personal consumption is simply to let the jars cool for a few hours and then place them in the freezer. If you have the freezer space, this is a great way to preserve the jam. Every spring and summer, I make large batches of jam, and then freeze the filled jars to enjoy throughout the year. Thaw frozen jars of jam overnight in the refrigerator before using.