How to make Lemon Mousse Cups

One of my all-time favourite desserts is lemon curd. It is tart, a little sweet, refreshing and delicious. The dish that we are going to look at today is lemon curd that has been lightened in both flavour and texture by the addition of whipped egg whites. The egg whites give the lemon curd an incredible airiness that is sure to please.

Jump to:

• Making lemon curd
• Making the mousse
• Serving the lemon mousse
• Tips for the Perfect Lemon Mousse
• Variations to Try
• Storage and Make-Ahead
• Final Thoughts
• Recipe

It's like having both the lemon and meringue in one homogenized spoonful. If you like lemon curd as much as I do then you are going to love this. Let's take a look.

Making lemon curd

As I said in the intro, this lemon mousse is made by first making lemon curd, then folding whipped egg whites into it. So, the obvious first step is to make the lemon curd. To do that start with 1 teaspoon fresh grated lemon zest, ⅓ cup lemon juice, ⅓ cup sugar, 2 egg yolks (the whites reserved), and ¼ cup of butter cut into small pieces.

Put all of these ingredients into a medium-sized heavy-bottomed pot on the stove on medium heat. Slowly whisk the mixture until it thickens. This will take between 8-12 minutes. Once the lemon curd has thickened, scrape it into a large metal bowl using a spatula. Set the lemon curd aside to cool slightly.

Making the mousse

With the lemon curd made and cooling the time has come to whip the egg whites. Make sure the bowl is very clean. It helps to wipe the side of the bowl down with a little vinegar or lemon juice as any grease on the sides of the bowl will prevent the egg whites from gaining the proper volume.

To start, turn the mixer onto a medium-low setting. Continue at this speed for 2-4 minutes or until the egg whites start to foam. At this point, you have the option of adding in 2 tablespoon of sugar. I left it out because I prefer my lemon curd and mousse to be fairly tart. If you like it a little sweeter, add 2 tablespoon of regular sugar into the egg whites now, then turn the speed up to high. If you aren't going to add extra sugar it is still time to turn the mixer up to high. Beat the egg whites on high until they form stiff peaks. That means if you dip a spoon into the egg whites and pull it out, any egg whites still on the spoon will hold their form.

Lemon Curd meet Whipped Egg Whites

Once the egg whites are whipped to stiff peaks they can be added into the lemon curd. The best way to do this is to divide the egg whites into thirds (approximately) and add them one third at a time. The first portion of egg whites can be mixed in to loosen the mixture.

The second and third portions should be folded in so that they maintain their volume. Once the final portion of egg whites has been fully incorporated into the lemon curd the mousse is ready and can be portioned into ramekins, wrapped with plastic and put in the fridge for a minimum of two hours.

Serving the lemon mousse

I really love lemon and raspberries together. They not only look great together but they also taste great. So, I like to serve this lemon mousse with a few raspberries. Garnish the dish with a sprig of mint for a pop of green and you have a beautiful dessert that anyone would be happy to eat.

Tips for the Perfect Lemon Mousse

This is a simple dessert, but a few small details can make the difference between good and great. Here are some things I have learned from making this over the years:

• Use fresh lemons. Bottled lemon juice will work in a pinch, but fresh juice and zest give the mousse a much brighter, more vibrant flavour.
• Make sure your bowl is spotless. Even a tiny bit of grease will prevent the egg whites from whipping properly. Wiping the bowl with a little lemon juice or vinegar helps.
• Don't over-fold. When incorporating the egg whites, fold gently and stop as soon as you no longer see white streaks. Over-folding will deflate the mousse and you will lose that wonderful airiness.
• Let the curd cool slightly before folding. If the lemon curd is too hot when you add the egg whites, it will cook them and deflate the mousse. Let it cool for about 10 minutes first.
• Chill for at least two hours. The mousse needs time to set in the fridge. Overnight is even better if you can manage the wait.

Variations to Try

Once you have mastered this basic lemon mousse, there are plenty of ways to mix things up:

• Lime mousse: Swap out the lemon juice and zest for lime. The result is equally delicious and pairs beautifully with fresh mango.
• Orange mousse: Use orange juice and zest for a sweeter, more mellow citrus flavour. You may want to reduce the sugar slightly.
• Lemon mousse with a cookie base: Crush some graham crackers or digestive biscuits, mix with a little melted butter, and press into the bottom of each ramekin before adding the mousse. It adds a wonderful crunch.
• Add whipped cream: For an even richer mousse, fold in ¼ cup of whipped cream along with the egg whites.

Storage and Make-Ahead

This lemon mousse is an excellent make-ahead dessert, which is one of the reasons I love it so much. Here is what you need to know:

• The mousse will keep in the fridge, covered with plastic wrap, for up to 3 days.
• Add fresh fruit and garnishes just before serving so they stay looking their best.
• This mousse does not freeze well due to the whipped egg whites. Freezing will cause the texture to break down.
• If you want to make it the morning of a dinner party, it will be perfectly set by evening.

Final Thoughts

This is one of my favourite light desserts, and I truly hope you love it too. It is the kind of dessert that feels fancy but is genuinely simple to put together, and it never fails to impress. If you enjoy light and elegant desserts like this, you might also love my panna cotta recipe or my sabayon, which is another beautiful simple summer dessert. Happy cooking!

Recipe