2 pounds raspberries
3 cups granulated sugar
Juice of 1 lemon
Rinse and mash berries. Place in a 6-quart or larger pot with sugar and slowly bring to a boil, stirring to dissolve sugar. Boil for 20 to 30 minutes, stirring frequently to prevent sticking and scorching, until thickened. Jam will thicken as it cools. Add lemon juice at the end of cooking time.
Remove from heat and skim off foam with a spoon. Ladle jam into clean, hot jars, leaving 1/2-inch headspace; seal. Process in a boiling water bath for 10 minutes.
Yield 4 to 5 half-pints.