Delia Smith Key Lime Pie

Some desserts are all about drama — towering layers, flamboyant frostings, the works. But this Key Lime Pie? It’s not trying to impress you. It knows it’s good. It’s cool, creamy, quietly confident. A little zippy, a little cheeky, and done before your dinner guests have even finished their first glass of wine.

The first time I made this pie, I was in a bit of a mood. It was hot, I was tired, and I wanted something sweet without breaking a sweat. Delia came through, as always. This pie took barely 30 minutes, and I remember standing barefoot in the kitchen eating a spoonful straight from the tin — bright, tangy, and perfectly chilled. It was, honestly, the best bite of the week.

Why You’ll Love It

• The filling’s a citrus dream — tangy, creamy, and sweet in perfect balance.
• That crust though… buttery, crunchy, with a cheeky Grape-Nuts twist.
• Ridiculously easy — if you can crush biscuits and whisk, you’re golden.
• Make-ahead friendly — sets up like a charm in the fridge.
• Feels like summer in a slice, even in the dead of winter.
• No faff toppings required, but whipped cream or crème fraîche never hurts.

Ingredients

For the base:

• 95g butter (about 3½ oz)
• 175g digestive biscuits (6 oz)
• 50g Grape-Nuts cereal (2 oz)

For the filling:

• Zest of 3 limes (about 1 tbsp)
• 150ml fresh lime juice (5 fl oz – juice of 4–5 big limes)
• 3 large egg yolks
• 400g sweetened condensed milk (14 oz)

To finish:

• Crème fraîche (just a dollop or two)
• Thin slices of lime

How to Make It

Make that golden base:

Melt your butter gently in a small pan — low heat, don’t rush it. While that’s going, bash your digestive biscuits to smithereens in a zip bag with a rolling pin. Tip the crumbs into a bowl and mix in the Grape-Nuts (yes, trust me). Pour over the melted butter and stir until it all looks like damp sand.

Press it with love:

Scoop the mixture into a flan tin and press it evenly along the bottom and up the sides with your fingers or the back of a spoon. Try to avoid gaps, or you’ll get leaks. Pop it on a baking tray.

Bake the crust till crisp:

Bake the base at 180°C (350°F) for 10–12 minutes — it should smell toasty and look golden. Let it cool while you make the filling.

Whip up the zingy filling:

In a bowl, whisk the egg yolks and lime zest with an electric mixer for about 2 minutes — it’ll thicken a little and smell gorgeous. Add the condensed milk and whisk again for 4 more minutes. Then pour in the lime juice and give it a quick final mix. It’ll look loose but don’t worry — it sets in the oven.

Fill and bake again:

Pour the filling into the cooled crust and smooth the top. Bake for another 20 minutes, until the centre feels just set when you gently press it.

Cool, chill, and (eventually) slice:

Take the pie out of the oven and let it cool completely in the tin. Once cooled, cover with clingfilm and chill for at least an hour — overnight if you’ve got the patience.

Serve it chilled with flair:

Slice and serve with a dollop of crème fraîche and a curl of lime zest or wedge of lime on top. A sprig of mint never hurts, either.

Common Mistakes and How to Dodge Them

Why is my filling too runny?
It probably needed more time to chill — or wasn’t baked quite long enough. The filling should have a slight wobble but feel set when gently touched.

The crust is crumbly or falling apart — help?
It’s likely you didn’t press it down firmly enough or didn’t use enough butter. Next time, really compact it — no loose bits!

My filling split — what did I do wrong?
If the lime juice goes in before the condensed milk’s fully incorporated, it can curdle. Always whisk the yolks and milk together first, then add the juice.

It tastes too sharp!
Some limes are cheekier than others. If yours are especially tart, a tablespoon or two of extra condensed milk balances things out

Storage and Reheating

Fridge:
Store the pie (covered) in the fridge for up to 4 days. The texture actually improves a bit with time.

Freezer:
Wrap tightly in clingfilm and foil, and freeze up to 2 months. Thaw overnight in the fridge — don’t microwave!

Reheating?
Honestly, no. It’s a chilled dessert. But if you must, 10 seconds in the microwave is the absolute max. And expect it to go a little soft.

Frequently Asked Questions

Can I skip the Grape-Nuts?
Sure — just replace with more crushed digestives. But Grape-Nuts give it a fab crunch.

Can I use bottled lime juice?
Technically yes, but fresh lime juice gives it that punchy, bright flavour. The real deal is always better.

Is this a traditional Key Lime Pie?
This is Delia’s twist — more British pantry than Floridian Keys, but every bit as dreamy.

What if I want to make it gluten-free?
Use GF biscuits and skip the Grape-Nuts (or find a crunchy GF cereal). The filling is naturally gluten-free.

Nutrition Facts (Per Serving):

• Calories: 440 kcal
• Fat: 22g
• Carbs: 54g
• Protein: 8.4g
• Sugar: 42g
• Sodium: 206mg

More Delia Smith Recipe:

• Delia Smith Chocolate Mousse
• Delia Smith Apple And Blackberry Crumble
• Delia Smith Cheesecake No Bake