This unusual and sophisticated marmalade blends the tart brightness of grapefruit with the aromatic complexity of vermouth. The result is a surprisingly delicious and unique preserve that’s perfect for elevating breakfast pastries, adding a touch of elegance to cheese boards, or even using as a glaze for roasted meats.
INGREDIENTS
- 4 medium pink grapefruits (about 3 pounds/1.4kg), preferably organic or unsprayed
- 4 cups (1L) water
- 2 3/4 cups (550g) granulated sugar
- Pinch of salt
- 3/4 cup sweet (red) vermouth

INSTRUCTIONS
- Prepare the Grapefruit: Using a paring knife, remove the peel from two of the grapefruits by cutting off the ends and slicing off the skin and white pith. It’s okay if some of the pith remains. Use the knife to cut the grapefruit sections away from the membranes. Place the sections in a large nonreactive pot and squeeze the juice from the remaining membranes into the pot. (You can reserve the peel for other uses like candying.)
- Juice the Remaining Grapefruits: Slice the remaining two grapefruits in half crosswise and juice them into the pot. Scrape out the membranes with a soup spoon and discard them.
- Prepare the Rinds: Cut each juiced grapefruit half into two quarters. Slice the rinds into strips about 1/4-inch (0.75cm) wide and add them to the pot, along with the water, sugar, and salt.
- Cook the Marmalade: Bring the mixture to a full boil, then turn off the heat, cover the pot, and let it stand for 1 hour (it can also sit overnight).
- Finish Cooking: If you have a candy thermometer, attach it to the side of the pot. Bring the mixture to a boil again, then reduce the heat to maintain a low boil. If you don’t have a candy thermometer, use a digital thermometer or follow the next steps. Place a small plate in the freezer to test the marmalade later.
- Check for Thickness: Continue to cook the mixture until it’s reduced by about half. Add the vermouth and keep cooking until the syrup thickens to the consistency of warm maple syrup, and the bubbles become thick and transparent. The temperature should reach around 215ºF (101ºC). To test if it’s done, place a bit of marmalade on the chilled plate, then return it to the freezer. After a few minutes, test with your finger; if the surface wrinkles, the marmalade is ready. If it’s not set, continue cooking and checking at intervals until it’s done.
- Jar the Marmalade: Once the marmalade is ready, turn off the heat and ladle it into clean jars with lids. If you plan to use it within a week or two, store it in the refrigerator, where it will last for several months.
NOTES
You can substitute the vermouth with another apéritif-style fortified wine, such as Byrrh, Dubonnet, or Cap Corse rouge. For a non-alcoholic version, try unsweetened grape juice or simply omit the alcohol.