With a buttery graham cracker crust and a silky grapefruit filling, this Grapefruit Tart is the perfect blend of tart and sweet. Whether you’re celebrating a summer birthday, hosting a brunch, or just craving something bright and refreshing, this grapefruit tart delivers.

If you’ve ever found lemon desserts a little too sharp (I have not!) or orange ones a little too sweet, let me introduce you to grapefruit. With its bold citrus tang and subtle floral sweetness, grapefruit brings a sophisticated twist to classic citrus desserts, and this tart is the perfect showcase.

We start with a coconut graham cracker crust (crunchy, buttery, and so easy – or use a regular coconut-free graham cracker crust), then fill it with a smooth, creamy grapefruit custard that bakes just long enough to set without losing any of its brightness.

If you’re a grapefruit fan, I’m confident this will earn a permanent spot in your dessert rotation. It has all the visual wow factor you want in a dinner party dessert (especially topped with whipped cream and a few slices of fresh grapefruit) but comes together with just a few ingredients.

Best of all, it’s the kind of dessert that holds up beautifully in the fridge or freezer. You can make it in advance, slice it cleanly with a sharp knife, and keep it chilled until you’re ready to serve.

Ingredients and Substitutions

• Graham Cracker Crumbs: Gluten-free graham crackers will result in a gluten-free tart. Digestive biscuits or vanilla wafers are other good alternatives.
• Granulated Sugar
• Salt
• Butter: Either salted or unsalted butter can be used for the crust.
• Shredded Coconut: Adding a little shredded coconut to the graham cracker crust is delicious, but this can be left out if you’re not a coconut fan.
• Sweetened Condensed Milk: Make sure to use sweetened condensed milk and not evaporated milk!
• Egg Yolks: Use the yolks from large eggs. Cold eggs are easy to separate, but let them come to room temperature before mixing them into the tart batter.
• Grapefruit: We need both the zest and the juice, so go ahead and buy a fresh grapefruit for this rather than trying to use grapefruit juice. Lemon or orange can be used instead of grapefruit for a different take on this tart.
• Food Coloring: This is entirely optional, but a few drops of red food coloring result in a classic “grapefruit” color. Without food coloring, the tart will be a soft peachy color.
• Whipped Cream

How to Make Grapefruit Tart

1. Make the Crust: Combine the graham cracker crumbs, sugar, pinch of salt, shredded coconut, and melted butter, then press firmly into the tart pan and bake until golden.

2. Mix the Filling: Whisk together the egg yolks, sweetened condensed milk, grapefruit juice, and grapefruit zest, along with a few drops of food coloring (if using).

3. Bake the Tart: Pour the grapefruit filling over the graham cracker crust. Bake until the edges of the tart are set but the center still has a slight wobble.

4. Cool: Cool the tart at room temperature, then transfer to the refrigerator and chill for several more hours. This two-step cooling process prevents the filling from cracking.
5. Decorate: Before serving, decorate with whipped cream and fresh slices of grapefruit. Serve chilled.

Setting the Custard

Citrus juice is acidic — grapefruit typically has a pH between 3.0 and 3.8 — and this acidity plays a major role in helping the custard set without requiring additional thickeners such as gelatin or cornstarch. How does this work? It’s time for my favorite subject… kitchen chemistry!

Kitchen Chemistry

The acid in grapefruit juice causes proteins in the egg yolk to denature and coagulate, which transforms the liquid filling into a smooth, sliceable custard. When combined with the sweetened condensed milk, which contains both sugar and milk proteins, the end result is a stable and creamy texture.

The key to a perfect grapefruit tart is balance. If there’s too much acid in the tart, the custard will curdle. We need an appropriate amount of sweetened condensed milk, as the high sugar content interfere with protein bonds, preventing them from becoming too tight.

Tips and Tricks for the Perfect Grapefruit Tart

1. Separate Cold Eggs: Yolks are less likely to break when eggs are cold, so separate the eggs straight out of the refrigerator, then bring the yolks to room temperature.
2. Save the Egg Whites: Egg whites can be frozen for future use – like in one of these recipes using extra egg whites.
3. Press Crust Firmly: Use a flat-bottomed measuring cup or glass for even pressure.
4. Don’t Overbake: Look for a slight jiggle in the center. Overbaking can cause cracking or a rubbery texture. The center of the tart should reach 175°F (79°C) using an instant-read thermometer.
5. Cool Gradually: Let the tart come to room temperature before refrigerating to prevent condensation or cracks.
6. Decorate: Pile on fluffy whipped cream, pipe it around the border, or decorate with fresh or candied grapefruit slices.
7. Clean Slices: Wipe your knife clean between slices for a picture-perfect presentation.
8. Storage: Store the tart covered in the refrigerator for up to 4 days or freeze in an airtight container for up to 3 months, thawing in the refrigerator before serving.
9. Recommended Tools: 10-Inch Tart Pan | Mixing Bowls | Microplane Zester | Citrus Juicer

More Citrus Desserts