Grapefruit & Blood Orange Oleo Saccharum

Zest 4 blood oranges (wide strips)
Zest from 1 ruby red grapefruit (wide strips)
3/4 cups superfine white sugar

Using a y-peeler, remove the zest from 4 blood oranges and 1 ruby red grapefruit, taking care not to remove too much of the bitter white pith. Place the peels in a sturdy glass bowl (I like to use one with a lid), add 3/4 cup of superfine white sugar, and aggressively muddle.

Once the sugar is damp from the oils released from the zest, seal the container and set it aside for at least four hours, preferably overnight. Periodically muddle the skins a bit more and stir the mixture to ensure that all of the sugar turns into syrup. When it’s time to make your cocktail, strain the oleo saccharum out the peels, pressing as much of the  syrup out of them as possible. It will keep in the refrigerator for two months.