Strawberry Jam - cooking recipe

Ingredients

2 quarts strawberries, cut and crushed to yield 5 cups crushed berries
7 cups sugar
1/2 teaspoon butter
1 (1 3/4 ounce) box pectin (SureJell brand preferred)

Preparation

Pour crushed berries into large boiler.
Measure sugar into seperate container and set aside.
Stir package of Sure-Jell into strawberries.
Add butter.
Bring berries and Sure-Jell to a full rolling boil (a boil that does not stop bubbling when stirred) then add sugar.
Stir constantly.
Stir in sugar, quickly.
Return mixture to a full rolling boil and boil exactly 1 minute, stirring constantly.
Remove from heat.
Skim foam from top with metal spoon.
Ladle quickly into jars that have been cleaned and preheated.
Clean rims of jars with clean hot cloth.
Place heated lids (lids that have been placed in simmering water for 1 minute) on jars and tighten rings.
Place jars in water bath canner for 5 minutes, then remove from canner, turn jars upside down for 5 minutes.
Return jars to upright position and let cool completely before storing.