Wash the raspberries thoroughly and remove any stems or leaves. Set them aside.
In a large pot, combine the raspberries, sugar, and lemon juice. Stir gently to combine.
Gradually bring the mixture to a boil over medium heat while stirring constantly to prevent the sugar from burning.
Once boiling, add the fruit pectin to the mixture and stir well.
Continue to boil the mixture for about 10-15 minutes, stirring frequently. You’ll notice that the jam thickens as it cooks.
To test the consistency, place a spoonful of the jam on a cold plate and let it sit for a minute. Run your finger through it; if it holds its shape, it’s ready.
Remove the pot from heat and skim off any foam that may have formed on the surface.
Carefully ladle the hot jam into the prepared canning jars, leaving about ¼ inch of headspace at the top.
Wipe the rims of the jars with a clean cloth to remove any residue, then place the lids on and screw the bands until they are fingertip-tight.
Process the jars in a boiling water bath for 5-10 minutes to ensure they are sealed.
Remove the jars from the water bath and let them cool on a clean kitchen towel for 24 hours.