Using a fruit peeler remove the zest of the oranges and lemons. Cut the zest pieces into thin slices, then finely chop or grind and set aside. Peel and discard remaining white part of the peel from fruit. Chop fruit pulp, reserving any juice and set aside. Place the peels, water and baking soda in a saucepan. Bring to a boil over high heat. Reduce the heat, cover and simmer for 20 minutes stirring occasionally. Add the reserved fruit and juice and cover. Simmer additional 10 minutes.
Stir the 6 cups sugar into the prepared fruit in the saucepan. Add the butter to reduce foaming. Bring mixture to a full rolling boil on high heat sirring constantly. Stir in pectin. Return to a boil and boil exactly 1 minute, stirring constantly. Remove from heat and skin off any foam with a metal spoon.
Toss the blueberries with honey. Place into a small saucepan and cook over medium heat for 1 minute. Scoop out blueberries and add to jam. Reduce liquid to a syrup and stir into the finished marmalade. Serve at room temperature.
For the Black Pepper Biscuits - Check out my recipe for them.