Place chopped apricots in large pot with the lemon juice. Add pectin and bring to a full, rolling boil. (Add 1/2 teaspoon butter to reduce foaming.) Meanwhile, get your sugar measured and ready. As soon as apricots, lemon juice, and pectin are at the boil, add sugar all at once. Return to boil and keep at the full, rolling boil for one minute. Remove from heat and ladle immediately into clean jars. Place lids on top, screw on bands, and lower onto rack in your pot of boiling water. BWB 10 minutes.