This all-American Classic Key Lime Pie may be one of the easiest pies that you have ever made.
It certainly will be one of the most delicious. The filling is creamy and smooth, with the bright, zesty flavour of lime which is balanced by the sweetened condensed milk. And then the irresistible creaminess of the filling is offset by the crisp, buttery, biscuit-crumb crust.
To begin with, although Key limes are, of course, recommended, it may not be possible to find them. I have used the Tahitian lime, also known as Persian lime.
My green-grocer tells me that the Tahitian lime is the variety most commonly found in grocery stores. The Tahitian lime tree is free of thorns, the fruit it produces is thicker-skinned and larger than the Key lime. These qualities, and the fact that it keeps longer make it a more viable commercial crop.
On the other hand, Key limes are much smaller than Tahitian limes, are thin-skinned, have very thorny branches and often contain some seeds. As Key limes are more acidic than Tahitian limes, I have added some lemon juice to this recipe to add acidity.
Why you’ll love this Classic Key Lime Pie:
I love how simple and easy this pie is to make. For a start, it does not have a pastry base so there’s no making dough and rolling out a crust. Further, there’s no lengthy list of hard to find ingredients. Just six every-day ingredients are needed to make this American classic dessert.
I am certain that this American classic, which is the perfect combination of zesty and refreshing yet fabulously creamy and smooth, will become a family favourite. Before you attend your next family celebration or large gathering, you can quickly and easily make this Classic Key Lime Pie. Further, it makes a fabulous Christmas dessert. Moreover, it is portable and would be a welcome addition to a pot-luck party.
I use these ingredients to make the Classic Key Lime Pie:
I like the flavour provided by these crumbly, golden wheat biscuits. However, you could also use Graham crackers or a digestive biscuit. Also, to make a gluten-free dessert, you can use a gluten-free biscuit for the crust.
I melt the butter and add it to the biscuit crumbs to make the base for the pie.
I have used just the egg yolks here. The fat in the egg yolks adds a pleasant smoothness to the filling. They also add richness and creaminess and help to set the pie. I have saved the egg whites to use in another recipe.
I use freshly squeezed lime juice which adds a fresh, zesty, vibrant flavour to the pie. I would strongly encourage you to not use bottled lime juice; it lacks the bright, zesty flavour of fresh lime juice and often contains a preservative.
I think that most of us are familiar with this fabulous ingredient which adds richness and sweetness to many recipes. It is, essentially, cows’ milk with added sugar and about 60 per cent of the water content removed. It is rich and thick, with a golden-yellow colour and a luscious, sweet flavour.
Heavy cream, which is also known as thickened cream or whipping cream, has a fat content of about 35%. These are suitable creams to whip. I add some whipped cream to the top of the finished pie. This is optional but I think it is an important step to add a finishing touch.
What is the difference between a Tahitian lime and a Key lime?
The differences between the two types of lime are subtle. The Tahitian lime, also known as the Persian lime, is the variety most commonly found at the greengrocer or supermarket. The fruit is larger and thicker-skinned than the Key lime and it keeps longer which makes it more commercially viable.
On the other hand, the fruit of the Key lime, also known as the West Indian lime, is smaller than the Tahitian lime and contains more seeds. Whilst they are similar in taste, the Key lime is slightly more acidic with a complex aroma and more intense flavour.
This is how I make the Classic Key Lime Pie:
To begin, I make a simple, crisp, buttery, biscuit-crumb base. I whiz some biscuits in a food processor until they resemble fine breadcrumbs. To the biscuit crumbs, I add some melted butter and whiz them together until they are well combined. I turn this mixture into a pie pan and then, using the back of a spoon or a flat-bottomed glass, I press the mixture onto the base and up the sides of the pan. I bake the crust for about 10 minutes to make it crisp.
Whilst the base is cooling, I prepare the filling. In a medium-size bowl, I add egg yolks and condensed milk and whisk to combine them. Then, I add lime and lemon juice and whisk again. It is so simple and easy; the filling comes together in no time.
Once the base is cool, I carefully add the filling and bake the pie for about 15 minutes or until the centre is just set. As tempting as it may be to eat straight away, you must set the pie aside to cool and then place it in the refrigerator to chill for at least 1 hour. Finally, I top the pie with whipped cream and it is ready to serve and enjoy.
Further ways to use these ingredients:
I have used a biscuit-crumb base in my delicious:
Fresh lime juice can be used in:
- Mushroom San Choy Bow
- Thai Vermicelli Noodle Salad
- Lime Vanilla Chiffon Cake by A Baking Journey
- Charred Corn and Black Bean Salad
- Mojitos by The Cooking Collective
- Thai Chicken Larb
- Lime and Blueberry Syrup Cake by Marcellina in Cucina
- Peach and Mint Smoothie
- Lime and Coconut Cake by Belly Rumbles
- Thai Inspired Prawn Salad
- Creamy Avocado Cilantro Lime Sauce by A Baking Journey
For leftover egg whites:
Leftover egg whites can be frozen for future use. Add the whites to containers which are suitable for the freezer. Seal the container and then label with the date, the number of egg whites and then freeze. Or, individual egg whites can be frozen in an ice cube tray. When frozen, they can be transferred to a container or zip-lock bag.
Alternatively, use them to make the following recipes:
- Almond Cookies – Gluten and Dairy Free
- Chewy Amaretti Cookies
- Mini Meringues with Berries and Cream
- Individual Lemon Curd Meringues
When it comes to serving:
After chilling the pie, I top it with some whipped cream, either spreading it across the top of the pie or piping some rosettes around the edge. I like to add some thinly sliced lime and lime zest to emphasise that it is a lime pie.
You can bake the pie a day ahead. However, it is best to add the whipped cream shortly before serving. Store the leftovers, if you have any, in the refrigerator.
This is a versatile pie. It is so easy to make that it is suitable for weeknight family dinners. On the other hand, it is also an elegant dish which is ideal for special occasions. Also, it is portable, ideal to take to celebrations with family or friends.
Please let me know in the comments below if you make the pie.
Classic Key Lime Pie
- 250 g plain sweet biscuits See Note 1
- 80 g melted butter
- 395 g sweetened condensed milk
- 4 large egg yolks See Note 2
- ½ cup lime juice, strained See Note 3
- 1 ½ tablespoon lemon juice, strained
- ½ cup heavy cream (optional) See Note 4
- 1 teaspoon icing/confectioners' sugar
- fresh lime slices – to garnish
For accuracy, we recommend weighing your ingredients. This will produce the best results.
- Preheat the oven to 180 Degrees C (350F).
Place the biscuits in the bowl of a food processor and pulse until they resemble fine breadcrumbs.Add the melted butter to the biscuit crumbs and process until well combined.
- You will need a 9” / 23 cm pie plate.Tip the biscuit and butter mixture into the pie plate. Using the back of a dessert spoon, or the base of a flat-bottomed glass, press the mixture over the base and up the side of the pie plate.
- Place the pie crust into the pre-heated oven and bake until golden, about 8-10 minutes.Remove the crust from the oven and set aside to cool completely. This will take about 15 minutes.
- Whisk the condensed milk and the egg yolks together in a large bowl.
Add the lime and lemon juice and continue to whisk until they are well combined.
- Carefully pour the filling into the pie crust and bake until the centre of the pie is just set – about 15 minutes.
- Set the pie aside and allow it to cool completely. This will take about 1 hour.
Cover the pie with cling wrap and place it in the refrigerator until cold; for at least one hour
For the topping:
- Whisk the cream and icing/confectioners’ sugar until it forms soft peaks. Do not over-whip the cream. Top the pie with the whipped cream or place it into a piping bag and pipe some rosettes around the edge of the pie. Decorate with lime slices or zest.
- As alternatives, you could use Graham Crackers or gluten-free biscuits.
- In the main text I have suggestions for ways to use the leftover egg whites.
- I only use freshly squeezed lime juice as the flavour is brighter and fresher. Bottled lime juice lacks the bright, zesty flavour of fresh lime juice. Furthermore, the bottled variety often contains a preservative.
- In Australia, heavy cream, which is also known as thickened cream or whipping cream, has 35% milk fat.
- In Australia the tablespoon is 20 ml or 4 teaspoons. In many other countries the tablespoon is 15 ml or 3 teaspoons. This means you may have to adjust your measurement. In essence, my measure for lemon juice is 6 teaspoons.
Please note, the nutritional information is an estimate only, and is derived from online calculators. For accurate results, we recommend calculating the nutritional information based on the ingredients you use.