Easy Key Lime Mousse

This easy recipe for Key Lime Mousse is quite possibly one of the quickest and easiest desserts you will ever make and one of the tastiest too! With only four ingredients, this no-bake, light as a cloud mousse combines cream cheese, sweetened condensed milk, frozen whipped topping, and tart key lime juice to make a light and refreshing dessert that you and your family will love!

Depending on the ingredients, a mousse’s texture can be light and fluffy or thick and creamy. Like this recipe for Key Lime Pie, this surprisingly simple recipe for Key Lime Mousse is in the light and fluffy category and will have everyone thinking you are a super chef! 

Here’s what you will need:

Only four simple ingredients:

• Key limes – give this mousse its bright, citrusy tart flavor. Although this recipe calls for key lime juice, regular Persian lime juice or even lemon juice can be used instead. 
• Cream cheese  – smooth and creamy with a slight tang; cream cheese gives the mousse body and helps to thicken it. 
• Sweetened condensed milk – provides a familiar, deep rich super-sweet taste that pairs beautifully with the tart lime juice. 
• Frozen whipped topping – is a true convenience food, it’s what makes this dessert so easy, and it’s what gives it such a beautiful, fluffy texture. 
• Key lime zest or strips of peel – an optional garnish to add more tangy lime deliciousness and a pop of color to this dessert. 

Here’s how to make it:

1. Juice the limes and set the juice aside. 
2. Use an electric mixer to beat the softened cream cheese until it is smooth and creamy. Do not try and mix in the rest of the ingredients until the cream cheese is completely soft and smooth, or your mousse will have lumps in it. 
3. Once the cream cheese is smooth, add the sweetened condensed milk and beat until it is combined. Then add the thawed whipped topping. Continue mixing until all ingredients are combined. 
4. Add the lime juice slowly and continue beating until the mixture is thick and smooth.
5. Pour into individual serving bowls or parfait glasses and chill in the refrigerator before serving.
6. Optional, garnish with a bit of lime zest or thin strips of lime peel. 

Variations: 

• Make a key lime pie, by pouring the lime mixture into a purchased graham cracker crust.
• You can also make individual tarts, by purchasing individual graham cracker tart shells and filling these with the lime mixture.
• Last, but not least, make tiny key lime bites, by purchasing a package of individual phyllo shells. Bake the phyllo shells in a 350-degree F. oven to crisp them up, allow them to cool, then fill them with the lime mixture. 

Frequently asked questions:

Why isn’t my key lime mousse green?

Key lime juice is a pale yellow color, and authentic key lime pies and mousse are a pale yellow color. If you see a green key lime pie, it has had food coloring added. 

What to serve this dessert with?

This light dessert makes a wonderful ending to a spring or summer barbecue or cookout. I like to serve it with Grilled Chicken, Grilled Grouper with Mango Salsa, Blackened Grouper, Smoked Spatchcock Chicken, or Blackened Steak.  

Storage and leftovers?

Your mousse can be stored covered in the refrigerator for three days. 

How many key limes does it take to make one cup of juice?

A lot! Although key limes are juicer than regular limes, they are so small; you will need around 20 to make one cup of juice. If you are using regular limes, you will need five or six. 

What can you substitute for key lime juice?

If the thought of squeezing all of those tiny limes makes you dizzy, you can substitute regular or Persian lime juice for the key lime juice. You can also substitute one cup of frozen limeade in a pinch. In addition, you can make a lovely lemon mousse by using fresh lemon juice. 

Do not substitute purchased bottled lemon or lime juice. It will give your mousse a bitter flavor. 

What’s the difference between pudding and mousse?

In general, mousse is lighter and fluffier than pudding. While both are creamy, pudding is usually cooked to thicken it, while mousse is thickened by the addition of whipped cream or frozen whipped topping. 

Sharon’s tips:

If your limes are hard to juice, put them in the microwave for 15-20 seconds to warm the fruit.  It will make them softer and easier to squeeze. Also, pressing down on them with your hand and rolling them on the counter will make them easier to juice. Last but not least, cut the lime in half and try sticking a fork in it and twisting to release more juice. 

To soften the cream cheese, unwrap it, and put it on a microwave-safe dish. Microwave for 15-20 seconds. Test to see if it’s softened by pressing it with the back of a spoon or your finger. If it doesn’t give easily, put it back in for another 10 seconds. 

To make a Key Lime Mousse Pie, pour the mixture into a pre-made graham cracker pie crust and chill before serving.

More recipes with citrus:

If you like the bright flavor citrus brings to a dish as I do, you also might be interested in these popular dessert recipes:

• Meyer Lemon Tart with a Gingersnap Crust
• Luscious Meyer Lemon Bars
• Meyer Lemon Ice Cream – No Cook
• Lemon Swirl Cheesecake
• Kumquat Pie
• No-Bake Frozen Lemonade Pie

If you need more recipes or menu ideas, you can find all of my dessert recipes here.

Special thanks to my long-time friend Diane Clark who shared this recipe with me so I could share it with you!

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📋 Recipe:

*This recipe was originally posted on June 10, 2016. It was republished on April 1, 2021, with new photos, expanded directions, and a new FAQ section.