Quick Recipe Version (TL;DR)
Quick Ingredients
- 1 1/2 cups (195 g) all-purpose flour
- 1 tsp baking powder, 1/2 tsp baking soda, 1/2 tsp fine salt
- 1 tbsp poppy seeds
- 3/4 cup (150 g) sugar + zest of 1 large ruby grapefruit
- 2 large eggs
- 1/2 cup (120 g) full-fat Greek yogurt or sour cream
- 1/2 cup (120 ml) neutral oil
- 1/4 cup (60 ml) fresh grapefruit juice
- 1/2 cup (100 g) sugar + 1/2 cup (120 ml) water + 6–8 very thin grapefruit slices (for candying)
- 1 cup (120 g) powdered sugar + 2–3 tbsp candied syrup + 1–2 tbsp fresh grapefruit juice + pinch salt
Do This
- 1. Heat oven to 350°F (175°C). Grease and line an 8.5 x 4.5 in loaf pan.
- 2. Rub zest into sugar. Whisk in eggs, yogurt, oil, grapefruit juice, and vanilla.
- 3. Whisk flour, baking powder, baking soda, salt, and poppy seeds. Fold into wet just until combined; rest 5 minutes.
- 4. Bake 55–65 minutes until a tester comes out clean; tent if browning early.
- 5. Simmer 1/2 cup sugar + 1/2 cup water; candy thin grapefruit slices 10–12 minutes. Reserve syrup.
- 6. Whisk glaze: powdered sugar + 2–3 tbsp warm candied syrup + 1–2 tbsp grapefruit juice + pinch salt.
- 7. Cool loaf 10 minutes in pan, then 45–60 on rack. Spoon on thin glaze; top with candied slices. Slice.
Why You’ll Love This Recipe
- Bright, slightly bitter-sweet grapefruit flavor that balances rich, moist crumb.
- Speckled with poppy seeds for a delicate crunch in every bite.
- Thin, glossy candied-grapefruit glaze that looks bakery-beautiful but is simple to make.
- Foolproof quick-bread method—no mixer needed and pantry-friendly ingredients.
Grocery List
- Produce: 2 large ruby grapefruits
- Dairy: Full-fat Greek yogurt or sour cream (1/2 cup)
- Pantry: All-purpose flour, granulated sugar, powdered sugar, poppy seeds, baking powder, baking soda, fine sea salt, neutral oil, vanilla extract
Full Ingredients
For the Grapefruit-Poppyseed Loaf
- 1 1/2 cups (195 g) all-purpose flour
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon fine sea salt
- 1 tablespoon poppy seeds (9 g)
- 3/4 cup (150 g) granulated sugar
- Finely grated zest of 1 large ruby grapefruit (about 1 tablespoon)
- 2 large eggs, at room temperature
- 1/2 cup (120 g) full-fat Greek yogurt or sour cream, at room temperature
- 1/2 cup (120 ml) neutral oil (canola, grapeseed, or light olive)
- 1/4 cup (60 ml) freshly squeezed ruby grapefruit juice
- 1 teaspoon vanilla extract
For the Candied-Grapefruit Syrup and Slices
- 1/2 cup (100 g) granulated sugar
- 1/2 cup (120 ml) water
- 6–8 very thin slices ruby grapefruit (seeds removed), from the second grapefruit
For the Thin Candied-Grapefruit Glaze
- 1 cup (120 g) powdered sugar
- 2–3 tablespoons warm candied-grapefruit syrup
- 1–2 tablespoons fresh ruby grapefruit juice, as needed to thin
- Pinch fine sea salt
- Optional: 1/2 teaspoon poppy seeds to finish
Step-by-Step Instructions
Step 1: Prep the pan and preheat
Heat the oven to 350°F (175°C) with a rack in the center. Lightly grease an 8.5 x 4.5-inch loaf pan, then line it with a parchment sling (long strip overhanging the long sides) for easy removal. Lightly grease the parchment too.
Step 2: Infuse the sugar with grapefruit zest
In a large mixing bowl, combine the granulated sugar and finely grated grapefruit zest. Use your fingertips to rub the zest into the sugar until the mixture feels like damp sand and smells very aromatic. This releases flavorful oils and tames bitterness.
Step 3: Make the batter
Whisk the eggs into the zest-sugar until glossy. Whisk in the yogurt (or sour cream), oil, grapefruit juice, and vanilla until smooth. In a separate bowl, whisk the flour, baking powder, baking soda, salt, and poppy seeds. Add the dry ingredients to the wet and gently fold with a spatula just until no dry streaks remain. Let the batter rest 5 minutes so the flour hydrates and the poppy seeds plump.
Step 4: Bake the loaf
Scrape the batter into the prepared pan and smooth the top. Bake 55–65 minutes, until the top is deep golden and a skewer inserted in the center comes out clean or with a few moist crumbs. If the loaf is browning too quickly at 40 minutes, tent loosely with foil. Cool in the pan for 10 minutes, then lift to a rack to cool 45–60 minutes before glazing.
Step 5: Candy the grapefruit slices and make syrup
While the loaf bakes, bring 1/2 cup sugar and 1/2 cup water to a gentle simmer in a skillet or wide saucepan over medium heat. Slide in the thin grapefruit slices in a single layer and simmer 10–12 minutes, flipping once, until slightly translucent and tender. Turn off the heat. Transfer slices to a rack to drip; reserve the aromatic syrup for the glaze and keep it warm.
Step 6: Mix the thin candied-grapefruit glaze
In a medium bowl, whisk powdered sugar with 2 tablespoons warm candied syrup and 1 tablespoon fresh grapefruit juice. Add more syrup or juice a teaspoon at a time until the glaze is thin and pourable, like heavy cream. Whisk in a pinch of salt to balance the bitterness.
Step 7: Glaze, garnish, and slice
When the loaf is just barely warm, place it on a rack set over a sheet of parchment. Spoon the glaze over the top, letting it run slowly down the sides in a thin sheen. Arrange a few candied grapefruit slices on top and, if you like, finish with a light sprinkle of poppy seeds. Let the glaze set 10–15 minutes before slicing with a sharp serrated knife.
Pro Tips
- Rub zest into sugar first—this unlocks citrus oils for a brighter loaf with less bitterness.
- Use room-temperature eggs and dairy for a smoother batter and taller rise.
- Do not overmix once the flour goes in; fold just until combined to keep the crumb tender.
- Bake by doneness cues, not time alone. A skewer should emerge clean or with a few moist crumbs.
- For a taller loaf, use an 8.5 x 4.5-inch pan. A 9 x 5-inch pan works but may bake 5–8 minutes faster.
Variations
- Herb perfume: Add 1 teaspoon finely chopped fresh rosemary or thyme to the glaze for an elegant savory note.
- Triple citrus: Swap half the grapefruit juice with lemon or orange for a mixed-citrus loaf.
- Almond twist: Replace vanilla with 1/2 teaspoon almond extract and top with toasted sliced almonds before glazing.
Storage & Make-Ahead
Store the glazed loaf airtight at room temperature for up to 3 days; the flavor deepens by day two. To freeze, wrap the unglazed loaf tightly in plastic and then foil, and freeze up to 2 months. Thaw, then glaze before serving. Candied grapefruit slices keep in their syrup in the refrigerator for 2 weeks; rewarm briefly to loosen before using. The glaze can be mixed up to 2 days ahead and refrigerated; thin with a little warm syrup or juice before glazing.
Nutrition (per serving)
Approximate per slice (1 of 10): 320 calories; 16 g fat; 43 g carbohydrates; 3 g protein; 25 g sugars; 1 g fiber; 220 mg sodium.
