This marmalade is great stirred into a gin or bourbon cocktail. Use a mild smoked salt, such as Maldon, so as not to overpower the sweet and aromatic grapefruit. Slideshow:  More Grapefruit Recipes 

March 2015


Credit: © John Kernick

Recipe Summary test

35 mins
Makes 7 1/2 cups


Ingredient Checklist


Instructions Checklist
  • In a medium bowl, whisk the sugar with the smoked salt and pectin.

  • In a large saucepan, whisk the grapefruit zest with the grapefruit and lemon juices and the calcium water and bring to a boil. Gradually whisk in the sugar mixture and bring back to a boil over high heat, whisking, until the sugar dissolves, about 3 minutes. Remove from the heat and skim off any foam. Test the marmalade: Spoon 1 tablespoon onto a chilled plate and refrigerate until it cools to room temperature, about 3 minutes; the marmalade is ready when it is thickened slightly and a spoon dragged through it leaves a clear trail. If the marmalade is too loose, continue simmering and test every 5 minutes.

  • Pour the marmalade into glass jars and let cool completely.


Pomona’s Universal Pectin (the brand favored by McCarthy for this recipe) is activated with calcium. A packet of calcium powder is included in each box—simply combine 1/4 teaspoon of the powder with 1/4 cup water to make the calcium water, which can be refrigerated for several months.