Bring boiling-water canner, half full with water, to simmer. Wash jars and screw bands in hot soapy water; rinse with warm water. Pour boiling water over flat lids in saucepan off the heat. Let stand in hot water until ready to use. Drain well before filling.
Stem and crush strawberries thoroughly, one layer at a time. Measure exactly 6 cups prepared fruit into 6- or 8-quart saucepot.
Mix 1/4 cup of the sugar (from the measured amount in bowl) and pectin in small bowl. Add to fruit in saucepot; mix well. Add butter to reduce foaming. Bring mixture to full rolling boil (a boil that doesn't stop bubbling when stirred) on high heat, stirring constantly. Stir in remaining 3-3/4 cups sugar. Return to full rolling boil and boil exactly 1 minute, stirring constantly. Remove from heat. Skim off any foam with metal spoon.
Ladle immediately into prepared jars, filling to within 1/4 inch of tops. Wipe jar rims and threads. Cover with 2-piece lids. Screw bands tightly. Place jars on elevated rack in canner. Lower rack into canner. (Water must cover jars by 1 to 2 inches. Add boiling water, if necessary.) Cover; bring water to gentle boil. Process 10 minutes. Remove jars and place upright on towel to cool completely. After jars cool, check seals by pressing middle of lid with finger. (If lid springs back, lid is not sealed and refrigeration is necessary.)
How to Measure Precisely
To get exact level cup measure of sugar, spoon sugar into dry metal or plastic measuring cup, then level by scraping excess sugar from top of cup with a straight-edged knife.
At altitudes above 1,000 feet, increase processing time as indicated: 1,001 to 3,000 feet-increase processing time by 5 minutes; 3,001 to 6,000 feet-increase processing time by 10 minutes; 6,001 to 8,000 feet-increase processing time by 15 minutes; 8,001 to 10,000 feet-increase processing time by 20 minutes.
Enjoy this lower sugar jam recipe, which has 15 fewer calories and 36% less sugar per serving than the original recipe which has 45 calories and 11g of sugar per serving.
Calories From Fat
% Daily Value*
Total Fat 0g
Saturated Fat 0g
Trans Fat 0g
Total Carbohydrates 8g
Dietary Fibers 0g
* Percent Daily Values are based on a 2,000 calorie diet.
Makes about 8 (1-cup) jars or 128 servings, 1 Tbsp. each.
* Nutrition information is estimated based on the ingredients and cooking instructions as described in each recipe and is intended to be used for informational purposes only. Please note that nutrition details may vary based on methods of preparation, origin and freshness of ingredients used.