Delia Smith Key Lime Pie​ Recipe​

This key lime pie is all about contrast: a crisp, buttery biscuit base topped with a silky, tangy lime filling that sets into a soft, creamy slice. The flavour is bright and citrusy, balanced by the sweetness of condensed milk and finished with a cloud of lightly sweetened whipped cream. It’s an easy, reliable bake with no tricky techniques, just a little patience while it chills. Total time is about 4 hours 40 minutes, including chilling.

Ingredients

For the Biscuit Base

• 250g digestive biscuits (or graham crackers), finely crushed
• 100g unsalted butter, melted
• 25g caster sugar
• Pinch of fine salt (optional)

For the Key Lime Filling

• 1 tbsp finely grated lime zest (from 2 to 3 limes)
• 400g sweetened condensed milk (1 x 400g tin)
• 4 large egg yolks
• 120ml key lime juice (or regular lime juice), freshly squeezed
• 1 tsp vanilla extract (optional)
• Pinch of fine salt

For the Topping

• 250ml double cream (heavy cream), cold
• 1 to 2 tbsp icing sugar, to taste
• Extra lime zest or thin lime slices, to finish

How to Make Delia Smith Key Lime Pie​ Recipe​

Oven Preparation

• Prepare the oven: Preheat the oven to 180°C or 160°C fan. Place a shelf in the middle of the oven so the crust bakes evenly.
• Prepare your tin: Lightly grease a 23cm pie dish or tart tin. If you are using a tart tin, place it on a baking tray for easy lifting.

Make the Biscuit Base

• Crush and mix: Tip the crushed biscuits into a bowl and stir in the caster sugar and salt. Pour over the melted butter and mix until it looks like damp sand.
• Press into the tin: Spoon the mixture into the tin and press firmly into the base and up the sides using the back of a spoon or the base of a glass. Take a minute here, a well-packed crust slices cleanly.
• Bake the crust: Bake for 10 minutes, then set aside to cool for about 10 minutes while you make the filling.

Mix the Filling

• Whisk the yolks: In a medium bowl, whisk the egg yolks for 20 to 30 seconds until loosened.
• Add condensed milk: Pour in the condensed milk and whisk until smooth.
• Finish with lime: Add the lime zest, lime juice, vanilla (if using), and a pinch of salt. Whisk until glossy and slightly thickened.

Bake

• Fill the crust: Pour the lime filling into the baked crust and gently level the surface.
• Bake until just set: Bake for 12 to 15 minutes, until the edges are set and the centre still has a small wobble. It should not look wet, just softly set.

Cool and Chill

• Cool gradually: Let the pie cool at room temperature for about 1 hour. This helps prevent condensation forming on top.
• Chill to set: Refrigerate for at least 3 hours, or overnight for the neatest slices.

Assemble and Finish

• Whip the cream: Whip the cold double cream with the icing sugar until soft peaks form. Keep it billowy rather than stiff for the best texture.
• Top the pie: Spread the cream over the chilled pie or pipe it around the edge. Finish with lime zest or thin slices.
• Slice and serve: For clean slices, dip a knife in hot water, wipe dry, and cut. Repeat between slices.

Tips

Why didn’t my key lime pie set properly?

The most common causes are underbaking or not chilling long enough. Bake until the edges are set and only the centre has a gentle wobble, then chill for at least 3 hours. Fresh lime juice also helps the filling thicken, bottled juice can be less reliable.

How do I stop the biscuit base from crumbling when I slice?

Press the crumbs firmly into the tin and bake the crust for the full 10 minutes. If you still find it crumbly, add an extra 10g to 15g melted butter next time to help it bind.

How can I get a stronger lime flavour without making it too sharp?

Add a little extra lime zest rather than extra juice. Zest gives a bigger lime aroma without changing the set of the filling.

How do I avoid weeping or watery topping?

Whip the cream to soft peaks and add the topping close to serving time if possible. If you need to top ahead, keep the pie very cold and avoid covering the cream directly with cling film, which can pull moisture onto the surface.

Serving Suggestions

• Serve straight from the fridge with extra lime zest over the top.
• Add fresh raspberries or strawberries on the side for colour and brightness.
• Pair with a short black coffee or strong tea to balance the sweetness.
• For a dinner party finish, add a few curls of white chocolate over the cream.

Storage

Room Temperature

Key lime pie should not be left out for long. Keep it at room temperature for up to 2 hours maximum, then return it to the fridge.

Refrigerator

Store covered in the fridge for up to 3 days. For the best texture, add the whipped cream topping on the day you plan to serve, or expect the cream to soften slightly by day two.

Freezing

You can freeze the pie (without the whipped cream topping) for up to 1 month. Wrap the set pie tightly in a double layer of cling film, then foil. Thaw overnight in the fridge and top with freshly whipped cream before serving.

Nutrition

• Calories: 430 kcal
• Carbohydrates: 46g
• Protein: 7g
• Fat: 25g
• Saturated Fat: 15g
• Sodium: 210mg

Disclaimer: Nutrition values are estimates and will vary depending on ingredients and portion size.

FAQs

Delia Smith Key Lime Pie Recipe

0.0 from 0 votes

Course: DessertCuisine: American, BritishDifficulty: Easy

Servings

10

slices

Prep time

25

minutes

Cooking time

25

minutes

Total time

280

minutes

Calories

430

kcal

50

minutes

A crisp biscuit base filled with a smooth, tangy key lime custard and finished with softly whipped cream. Easy to make, beautifully set, and perfect served chilled.

Ingredients

• 250g digestive biscuits (or graham crackers), finely crushed

• 100g unsalted butter, melted

• 25g caster sugar

• Pinch of fine salt (optional)

• 1 tbsp finely grated lime zest (from 2–3 limes)

• 400g sweetened condensed milk (1 tin)

• 4 large egg yolks

• 120ml key lime juice (or regular lime juice), freshly squeezed

• 1 tsp vanilla extract (optional)

• Pinch of fine salt (for the filling)

• 250ml double cream (heavy cream), cold

• 1–2 tbsp icing sugar, to taste

• Extra lime zest or thin lime slices, to finish

Directions

• Preheat the oven to 180°C (160°C fan). Lightly grease a 23cm pie dish or tart tin.
• Mix crushed biscuits with melted butter, sugar, and a pinch of salt. Press firmly into the base and up the sides.
• Bake the crust for 10 minutes, then cool for 10 minutes.
• Whisk lime zest, condensed milk, egg yolks, lime juice, vanilla (optional), and a pinch of salt until smooth and slightly thickened.
• Pour filling into the warm crust and bake for 12–15 minutes, until the edges are set and the centre still has a slight wobble.
• Cool to room temperature, then chill for at least 3 hours (or overnight) until fully set.
• Whip the cold double cream with icing sugar to soft peaks. Spread or pipe over the chilled pie and finish with lime zest.

Notes

• Fresh lime juice gives the cleanest flavour and helps the filling set properly.
• For neat slices, chill overnight and cut with a hot, dry knife.
• Add the whipped cream just before serving for the freshest finish.