📝 About This Recipe
This quintessential British preserve is a masterclass in the balance of bright acidity and rich, buttery indulgence. Unlike a jam, this curd relies on a gentle custard base to achieve its signature silk-smooth texture and vibrant, neon-yellow hue. It is an intensely aromatic spread that captures the very essence of fresh citrus, making it an essential staple for any sophisticated baker's larder.
🥗 Ingredients
The Citrus Base
- 4-5 large Fresh Lemons (unwaxed and organic if possible)
- 1 tablespoon Lemon Zest (finely grated, avoid the white pith)
- 3/4 cup Fresh Lemon Juice (strained of all seeds and pulp)
The Custard Foundation
- 1 cup Granulated Sugar (superfine or caster sugar works best)
- 6 Large Egg Yolks (at room temperature for better emulsification)
- 1 Large Whole Egg (adds structure to the curd)
- 1/4 teaspoon Fine Sea Salt (to balance the sweetness and acidity)
The Finishing Elements
- 8 tablespoons Unsalted Butter (high-quality European style, cubed and chilled)
- 1/2 teaspoon Pure Vanilla Extract (optional, for a rounded floral note)
👨🍳 Instructions
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1
Begin by zesting your lemons using a microplane, ensuring you only take the yellow skin and none of the bitter white pith. Set the zest aside.
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2
Juice the lemons until you have exactly 3/4 cup of liquid. Pass the juice through a fine-mesh sieve to remove any stray seeds or large bits of pulp.
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3
Prepare a double boiler: Fill a medium saucepan with 1-2 inches of water and bring it to a gentle simmer. Find a heatproof glass or stainless steel bowl that sits snugly over the pot without touching the water.
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4
In the heatproof bowl (off the heat), whisk together the granulated sugar, egg yolks, and the whole egg until the mixture is pale and slightly frothy.
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5
Slowly pour the lemon juice and the sea salt into the egg mixture, whisking constantly to ensure the ingredients are fully combined.
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6
Place the bowl over the simmering water. Reduce the heat to low to maintain a very gentle simmer; excessive heat will scramble the eggs.
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7
Whisk the mixture constantly. Do not walk away. You want to cook the curd slowly until it thickens to a consistency similar to hollandaise sauce or thick pudding.
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8
The curd is ready when it reaches 170°F (77°C) on an instant-read thermometer, or when it heavily coats the back of a wooden spoon and a finger swiped across leaves a clear path.
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9
Remove the bowl from the heat immediately. Stir in the lemon zest and the vanilla extract if using.
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10
Add the chilled, cubed butter one piece at a time. Whisk each piece in until completely melted and incorporated before adding the next. This creates a stable, velvety emulsion.
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11
For a truly professional, 'silk' finish, pour the hot curd through a fine-mesh sieve into a clean bowl to catch any tiny bits of cooked egg or zest.
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12
Press a piece of plastic wrap directly onto the surface of the curd to prevent a skin from forming as it cools.
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13
Let the curd cool at room temperature for 30 minutes, then refrigerate for at least 3 hours, or ideally overnight, to allow it to set completely.
💡 Chef's Tips
Always use a non-reactive bowl (glass or stainless steel) as the acid in lemons will react with aluminum or copper, giving the curd a metallic taste and a dull grey color. If your curd looks lumpy, don't panic! Straining it through a fine-mesh sieve while hot will fix almost any texture issue. For an even deeper flavor, rub the lemon zest into the sugar with your fingertips before starting; this releases the essential oils into the sugar. Never let the water in your double boiler touch the bottom of the bowl, as this localized high heat is the primary cause of curdled eggs. You can substitute the lemons for limes, passionfruit, or blood oranges using the same ratios for different flavor profiles.
🍽️ Serving Suggestions
Fold the chilled curd into freshly whipped cream to create a 'Lemon Fool' dessert. Spread generously between layers of a vanilla sponge cake or use as a vibrant filling for pre-baked tart shells. Serve alongside warm, buttery scones and clotted cream for a traditional English afternoon tea. Swirl into Greek yogurt or overnight oats for a bright, citrusy breakfast kick. Drizzle over toasted brioche or blueberry pancakes for a decadent brunch treat.