Stir in granulated sugar quickly (all at once). Stir well to combine. Bring the jam/pectin/sugar mixture back to a full, rolling boil. Once it is a full rolling boil, boil it for exactly 4 minutes, stirring constantly. When time is up, remove pan from heat, then skim off any accumulated foam (and discard).
Altitude Adjustments:Higher altitudes require additional processing times:
1-3 K feet = +5 min. 3-6 K feet = +10 min. 6-8 K feet = +15 min.
Orange Marmalade https://www.thegratefulgirlcooks.com/orange-marmalade/