Raspberry Jelly

Combine raspberries and water in a flat-bottomed kettle; crush the berries. Cover and bring to a boil. Reduce heat; simmer uncovered for 10 minutes, stirring frequently. Strain the berries through a moistened jelly bag, reserving 3 1/2 cups of juice; remove the pulp.Combine the remaining juice and lemon juice in a teapot, stirring well; bring to a boil. Add the sugar, stirring occasionally, until the sugar is dissolved. Continue cooking until the mixture begins to drain from a cold metal spoon. Remove from heat and use a metal spoon to remove the foam.Pour the jelly into hot sterilized jars, leaving 1/4 inch of space. Cover immediately with metal lids; tighten the ribbons tightly. Cook the jelly in a boiling water bath for 5 minutes.