Mulberry Jam

Put berries in saucepan and crush. Heat gently until juice starts to flow. Then, simmer covered, for 15 min. Put into jelly cloth or bag and squeeze out the juice. Measure out 3 cups of juice into a very large saucepan. Add sugar and lemonjuice, mix well. Put over high heat and bring to a boil, stirring constantly. At once stir in the pectin. Then, bring to a rolling boil and boil hard for 1 min., stirring constatly. Remove from heat skim off the foam, with a metal spoon. Pour quickly into hot sterilized jars and then seal. Makes about 8 1/2 pint jars.