Mary Berry Lemon Mousse

The first time I made this lemon mousse, I was halfway through spooning it into the glasses when I realised I’d forgotten the lemon juice. Classic. I’d been so focused on not eating all the lemon curd straight from the jar (it was the posh stuff, from a weekend market stall in Devon) that I missed the zingiest bit of the whole recipe.

But here’s the wild part: even without the juice, it still tasted amazing. That’s when I knew I was onto something special. Once I got the balance right—and trust me, I did—it became one of my go-to puddings when I need something quick but impressive. No gelatin, no faff, just creamy, tangy fluff layered over sharp berries and this oddly addictive crunchy oat topping.

Let me show you how I fixed that first flop and why I now double the topping every time…

Why This One Works So Well

It’s all about texture and balance. The lemon mousse itself is a dreamy blend of crème fraîche and Greek yoghurt—thick, smooth, and rich without being too heavy. The lemon curd and juice bring that sharp, sunny tang that hits just right against the cool creaminess.

But honestly? The crunchy hazelnut oat topping steals the show. Most lemon mousse recipes go soft-on-soft—creamy mousse, maybe a soft sponge—but the crunch makes this sing. It’s like a crumble topping’s cooler cousin, and it keeps its texture even when made ahead.

INGREDIENTS + WHY THEY MATTER

• Full-fat crème fraîche – Adds richness and a subtle tang. I tried low-fat once. Regretted it instantly. Don’t do it.
• Greek yoghurt – Brings body and a bit of protein structure. Use the thick, unsweetened kind.
• Luxury lemon curd – This matters. The cheap stuff is too sweet and gloopy. Look for one with real butter and eggs.
• Fresh lemon juice – That hit of acid cuts the creaminess perfectly. Bottled just doesn’t cut it.
• Fresh blueberries – Tart and juicy. I’ve tried raspberries, but they break down too fast.
• Butter + honey – Binds the topping and adds flavour. The honey gives a floral note that sugar alone doesn’t.
• Porridge oats – Texture heaven. Don’t use instant—they’ll turn dusty.
• Demerara sugar – Gives crunch and a slight caramel edge.
• Hazelnuts – Toasty, nutty contrast. Almonds work, but hazelnuts are best.
• Plain flour – Helps bind the topping into little golden clusters.

WANT TO CHANGE IT UP

• No hazelnuts? Use pecans or almonds. Just keep the ratio the same.
• Dairy-free? I’ve tested with coconut yoghurt + oat cream. Texture holds, flavour shifts a bit sweeter.
• Egg-free? No eggs in the base recipe, so you’re already sorted.
• Want it sharper? Add the zest of the lemon as well as the juice.
• Berries swap? Strawberries go mushy. Blackberries are fine, but chop them up.

MISTAKES I’VE MADE (AND HOW TO AVOID THEM)

What Went Wrong	Why It Happens	How to Fix It
Mousse was too loose	Skimped on chilling time	Chill for at least 1 hour (2 is better)
Topping burned on edges	Oven too hot / didn’t stir halfway	Bake at correct temp and stir at 10 mins
Blueberries floated up	Didn’t press them in firmly enough	Push them down gently with the back of a spoon
Mousse tasted too bland	Used cheap lemon curd	Get the good stuff—it makes a difference

HOW TO MAKE MARY BERRY’S LEMON MOUSSE

1. Preheat oven to 180°C (160°C fan). Line a baking tray with paper.
2. Make the topping: Melt butter and honey in a small pan. Stir in oats, sugar, chopped hazelnuts, and flour. Spread on tray and bake 15–20 minutes, stirring halfway. It should be golden and clumpy. Let it cool—it crisps as it cools.
3. Mix the mousse: In a bowl, stir together crème fraîche, yoghurt, lemon curd, and lemon juice. Don’t whisk—it should be creamy, not fluffy.
4. Assemble: Divide blueberries between 6–8 small glasses. Press them down gently. Spoon mousse over the berries. Top generously with crunchy hazelnut oat topping.
5. Chill: Pop them in the fridge for at least an hour before serving.

TIPS FROM MY KITCHEN

• I double the topping now and keep it in a jar. It’s unreal on porridge.
• Taste your lemon curd first—some are sweeter than others. Adjust with more juice if needed.
• I use my old whisky tumblers for this. They’re the perfect size.
• If you need to prep ahead, keep topping separate and add just before serving.

STORAGE + SERVING

• Fridge: Lasts up to 2 days. Cover with cling film.
• Freezer: Not worth it—the texture splits. Just don’t.
• Serve with: Shortbread fingers, almond biscotti, or a few more fresh berries. A splash of limoncello on the side doesn’t hurt either.

LEMON MOUSSE FAQs

Q: Can I make lemon mousse the night before?
A: Absolutely. Just keep the topping separate until the last minute so it stays crisp.

Q: What can I use instead of crème fraîche?
A: I tested with mascarpone once—delicious but much heavier. Sour cream works too but is tangier. Stick to full-fat if you can.

Q: Is Greek yoghurt enough on its own?
A: I tried it—too sharp and runny. The crème fraîche balances it and gives that lush texture.

Q: Can I use frozen blueberries?
A: Not ideal—they release too much liquid and make the base soggy.

Try More Mary Berry Recipes:

• Mary Berry’s Chocolate Yoghurt Cake
• Mary Berry Orange Shortbread Fingers
• Mary Berry Apple Tart
• Mary Berry Granny’s Little Shortbread Biscuits