Mary Berry’s Key Lime Tranche is a luscious, refreshing dessert that perfectly balances tartness and sweetness, all wrapped up in a creamy, velvety texture. Inspired by the classic American Key Lime Pie, this version has Mary Berry’s signature British twist, transforming it into a sophisticated, sliceable ‘tranche’ (French for ‘slice’), rather than a traditional pie.
What sets this dessert apart is its impeccable layering – a crisp, buttery biscuit base that provides the perfect crunch contrasts beautifully with the smooth, tangy, and silky key lime filling. The filling is usually made from fresh key lime juice, cream cheese or mascarpone, sweetened condensed milk, and sometimes a bit of whipped cream, all whipped together to a luxurious consistency.
The beauty of Mary Berry’s Key Lime Tranche lies in its simplicity and elegance. It’s not overly sweet but instead refreshingly bright, making it an ideal summer dessert or a show-stopping centerpiece for any special occasion. Imagine cutting into the slice, seeing the perfectly defined layers, and tasting the zingy citrus notes with the rich, creamy texture – it’s a symphony for the palate.
Mary Berry’s Key Lime Tranche Recipe
Ingredients Needed
To craft this divine dessert, you’ll need a harmonious blend of fresh and pantry staples. Mary Berry’s recipes typically emphasize quality ingredients, so it’s worth sourcing the freshest limes and the best-quality dairy you can find. Here’s a rundown of what you’ll need:
- Digestive Biscuits or Graham Crackers: About 200g, crushed finely to form the base crust. These provide the perfect buttery crunch.
- Unsalted Butter: Around 100g, melted, to bind the biscuit crumbs together and create that rich, golden crust.
- Key Lime Juice: Approximately 120ml (about 4-5 key limes). Key limes are smaller and more aromatic than regular limes, giving the dessert its signature tartness.
- Lime Zest: From 2 limes, to intensify the citrus flavor.
- Sweetened Condensed Milk: 397g (a standard can), this adds sweetness and a creamy consistency to the filling.
- Cream Cheese or Mascarpone: About 250g, softened. This ingredient adds richness and creaminess.
- Double Cream (Heavy Cream): 150ml, whipped lightly to add airiness and balance the tartness with smooth texture.
- Caster Sugar: 2-3 tablespoons, to sweeten the cream cheese mixture lightly.
- Gelatin (optional): A small amount to help set the filling if you prefer a firmer texture.
You may also want a pinch of vanilla extract or a touch of salt to elevate the flavors subtly, depending on your preference.
Equipment Needed
To make Mary Berry’s Key Lime Tranche perfectly, having the right tools is essential – they help you achieve that smooth, even texture and clean, sharp slices that make this dessert so appealing.
- Springform Cake Tin (about 8 inches/20 cm diameter): Ideal for easy removal of the tranche without damaging the delicate edges.
- Mixing Bowls: One large bowl for the biscuit base and another for the filling.
- Electric Mixer or Stand Mixer: To whip the cream and blend the filling until silky smooth.
- Zester or Microplane: For finely grating lime zest.
- Citrus Juicer: Handy for extracting fresh key lime juice without seeds.
- Spatula: For folding ingredients gently.
- Measuring Cups and Spoons: Accurate measurements ensure the perfect balance of flavors.
- Food Processor or Rolling Pin: To crush the biscuits finely.
- Saucepan (optional): If using gelatin, for dissolving it carefully.
- Refrigerator: To chill the tranche and let it set properly.
Instructions To Make Mary Berry’s Key Lime Tranche
Ready to create a masterpiece? Here’s a detailed step-by-step guide that will walk you through every stage of making this divine dessert:
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Prepare The Biscuit Base
- Start by crushing the digestive biscuits (or graham crackers) into fine crumbs. Use a food processor for ease or place them in a ziplock bag and crush with a rolling pin.
- Melt the unsalted butter gently, then pour it over the biscuit crumbs.
- Mix thoroughly until the crumbs are evenly coated and resemble wet sand.
- Press this mixture firmly and evenly into the base of your springform tin. Use the back of a spoon or a flat-bottomed glass to smooth it out and compact it well.
- Chill in the fridge for at least 15-20 minutes to set the base.
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Make The Key Lime Filling
- In a large mixing bowl, beat the softened cream cheese or mascarpone with caster sugar until smooth and creamy.
- Add the sweetened condensed milk slowly while continuing to beat, making sure everything is fully incorporated.
- Stir in the fresh key lime juice and lime zest, folding gently to maintain the airiness.
- Whip the double cream until soft peaks form, then fold it carefully into the lime mixture to create a light, fluffy texture.
- If using gelatin, dissolve it in a little warm water, cool slightly, then fold into the mixture to help the filling set more firmly.
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Assemble The Tranche
- Pour the key lime filling over the chilled biscuit base in the tin.
- Smooth the top with a spatula for an even finish.
- Cover with cling film and place in the fridge for at least 4 hours, ideally overnight, to allow the flavors to meld and the filling to set beautifully.
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Serving
- Once set, run a warm knife around the edges to loosen the tranche before carefully removing the springform tin sides.
- Slice into neat wedges using a sharp knife wiped clean between cuts for perfect presentation.
- Optionally, garnish with lime zest curls, thin slices of lime, or a dollop of whipped cream.
Tips And Tricks
To elevate your Key Lime Tranche to Mary Berry standards (and beyond!), here are some expert tips that will make all the difference:
- Use Fresh Key Limes if Possible: Their aromatic zest and juice are more flavorful and less bitter than regular limes.
- Don’t Overbeat the Cream: Whip until soft peaks form; overwhipping can cause it to split.
- Chill the Base Well: A well-set base ensures clean slicing and a satisfying crunch.
- Adjust Sweetness to Taste: Key limes can be quite tart, so tweak sugar levels depending on your palate.
- Gelatin is Optional: If you prefer a mousse-like texture, skip the gelatin. For firmer slices, use a little dissolved gelatin.
- Room Temperature Ingredients: Make sure cream cheese or mascarpone is softened to avoid lumps in the filling.
- Lime Zest for Extra Punch: Don’t skimp on the zest – it adds a vibrant burst of citrus aroma.
- Clean Knife Between Cuts: For pristine slices, wipe your knife with a warm damp cloth between each slice.
- Presentation Matters: Add some finely grated lime zest or a few edible flowers on top to impress guests.
Mary Berry’s Key Lime Tranche is more than just a dessert – it’s a celebration of balance, texture, and fresh, vibrant flavor. This recipe is a perfect example of how simple ingredients, when combined thoughtfully and prepared with care, can create something truly extraordinary. Whether you’re serving it at a summer party, a dinner gathering, or simply indulging on a sunny afternoon, this tranche promises to delight with its creamy, tangy layers and buttery crunch.
With its easy-to-follow steps and the ability to customize sweetness and tartness, Mary Berry’s Key Lime Tranche is an accessible yet sophisticated treat for both novice bakers and experienced cooks. So why not gather your ingredients, dust off that springform tin, and embark on this delicious journey? The zing of fresh key lime, the crumbly buttery base, and the smooth cream filling will surely have everyone asking for seconds – or even thirds!
Easy Recipe Variations For Mary Berry’s Key Lime Tranche
Mary Berry’s Key Lime Tranche is already a shining star in the realm of citrus desserts, blending zesty lime with a beautifully smooth, creamy base atop a crunchy biscuit crust. But one of the best things about this recipe is how versatile it can be-perfectly adaptable to fit your flavor preferences, dietary needs, or simply to add a little creative flair.
1. Coconut Key Lime Tranche:
A tropical twist on the classic, swap out a portion of the digestive biscuit base with shredded toasted coconut or even use coconut-flavored biscuits. The subtle sweetness and nuttiness of coconut pair gorgeously with the tangy lime, transporting your taste buds straight to a sun-drenched beach. For the topping, sprinkle more toasted coconut flakes for added texture and aroma.
2. Vegan and Dairy-Free Version:
For those who avoid dairy, you can replace the traditional cream cheese and condensed milk with plant-based alternatives. Silken tofu blended with coconut cream and a splash of lime juice can mimic the creamy, tangy texture of the filling. Use vegan biscuits for the base, and a touch of maple syrup or agave nectar can replace condensed milk’s sweetness. The result is just as luscious and refreshing, but completely plant-based.
3. Mixed Citrus Burst:
Why stop at lime? Enhance the tranche by adding layers of other citrus juices-like grapefruit, orange, or even blood orange-creating a complex citrus medley. You can either swirl these juices into the lime filling or create a layered effect, each with a different citrus, for a stunning visual and flavor profile that excites the palate.
4. Key Lime and Berry Fusion:
Introduce fresh or macerated berries such as raspberries, blueberries, or blackberries to the top of the tranche just before serving. The tart sweetness of berries provides a juicy contrast to the tart lime custard. Alternatively, fold some pureed berries gently into the lime mixture to create a marbled effect, giving the slice bursts of fruity color and flavor.
5. Ginger or Chili Infusion:
For the adventurous palate, a hint of spice can elevate this dessert. Add freshly grated ginger or a tiny pinch of chili powder to the lime filling. The warming spice perfectly balances the tartness, creating a depth of flavor that’s unexpected but utterly delightful. Serve with a dollop of whipped cream to mellow the heat.
These variations showcase how Mary Berry’s Key Lime Tranche can be a canvas for creativity, allowing you to tailor the dessert to your mood or occasion. Whether sticking close to the classic or exploring bold new directions, the base recipe is a reliable springboard for delicious experimentation.
Storing Leftovers
One of the delightful things about Mary Berry’s Key Lime Tranche is that it keeps well, making it perfect for preparing ahead or savoring over a few days. However, given its creamy texture and citrus freshness, proper storage is essential to maintain the best taste and texture.
Refrigeration:
After baking and cooling, store the tranche in an airtight container or cover it tightly with cling film or foil. This prevents the slice from absorbing any fridge odors and protects the delicate lime flavor. It’s best kept chilled and should last for about 3 to 4 days in the refrigerator. The lime flavor often becomes more pronounced after resting overnight, so if anything, the next-day slice is even better!
Freezing:
If you want to keep the tranche longer, freezing is an option, though it does require a bit more care. Wrap the tranche tightly in cling film and then again in aluminum foil to protect against freezer burn. Store it flat in the freezer, ideally for up to 1 month. When ready to serve, thaw slowly in the refrigerator overnight. Note that the texture may change slightly-the filling can become a bit softer, and the crust might lose some of its crunch-but it will still taste delicious.
Serving Tips for Leftovers:
Before serving refrigerated leftovers, let the tranche sit at room temperature for 10-15 minutes to allow the filling to soften slightly, enhancing the creamy mouthfeel. If the crust feels a little soggy, a quick blast under a grill or in a toaster oven for a minute or two can revive its crunchiness-just watch it closely!
What To Eat With Mary Berry’s Key Lime Tranche?
While Mary Berry’s Key Lime Tranche is a showstopper on its own, pairing it thoughtfully can elevate the entire dessert experience.
1. Fresh Fruit:
Complement the zesty lime with fresh seasonal fruits. Slices of ripe mango, juicy strawberries, or even a handful of pomegranate seeds add bursts of freshness and color. The natural sweetness of the fruit balances the tartness beautifully.
2. Cream or Ice Cream:
A generous dollop of softly whipped cream or vanilla ice cream is a classic accompaniment. The creamy, mild sweetness counters the lime’s tang and adds a luscious, velvety contrast. For a more adventurous pairing, try coconut or mango sorbet for a tropical flair.
3. Mint or Basil Garnish:
A few fresh mint leaves or small basil sprigs can add a refreshing herbal note. Their aroma and flavor provide a subtle lift that complements the lime’s brightness, adding a sophisticated touch to your presentation.
4. Light, Crisp Wine:
If serving adults, a glass of chilled Sauvignon Blanc, with its citrusy notes and crisp acidity, pairs perfectly. Alternatively, a sparkling wine or Prosecco adds celebratory bubbles that contrast nicely with the creamy texture.
5. Nutty Crunch:
Sprinkle some toasted pistachios, chopped almonds, or pecans over the top or on the side. This adds an unexpected crunch and nutty depth, complementing the smooth lime filling and crumbly base.
6. Coffee or Tea:
For a cozy end to the meal, a cup of freshly brewed coffee or a zesty green tea can cleanse the palate and enhance the dessert’s citrus flavors. Herbal teas like chamomile or mint also offer a soothing counterpoint.
These pairings don’t just fill out the plate-they add layers of flavor, texture, and aroma that make the Key Lime Tranche experience more rounded, memorable, and satisfying.
Conclusion
Mary Berry’s Key Lime Tranche is a delightful dessert that brilliantly combines tangy lime with creamy indulgence and a crunchy biscuit base, creating a perfect harmony of textures and flavors. Its straightforward recipe makes it accessible for bakers of all levels, while its adaptability invites endless creativity-from tropical coconut riffs to bold berry infusions or even warming spices.
Proper storage ensures you can enjoy this slice of sunshine well beyond the day it’s made, with the flavors often deepening and maturing with a bit of rest. And when served thoughtfully-with fresh fruits, creamy accompaniments, or a crisp wine-it becomes more than just dessert; it transforms into an experience that lingers on the palate and in the memory.
Whether you’re entertaining guests, celebrating a special occasion, or simply indulging in a moment of self-care, Mary Berry’s Key Lime Tranche is a stunning choice. Its refreshing zing and comforting creaminess offer a bright, cheerful finale to any meal. So go ahead-experiment with variations, savor the leftovers, and pair it with your favorite flavors. You’re not just making a dessert; you’re crafting a little slice of joy.
FAQs
What Ingredients Are Needed For Mary Berry’s Key Lime Tranche?
Mary Berry’s Key Lime Tranche recipe requires a mix of fresh lime juice, digestive biscuits, butter, double cream, condensed milk, and lime zest. For the base, you will need crushed digestive biscuits and melted butter. For the creamy filling, the recipe uses double cream, condensed milk, and freshly squeezed lime juice, creating a sweet yet tangy flavor profile.
How Do I Assemble Mary Berry’s Key Lime Tranche?
To assemble the Key Lime Tranche, start by preparing the biscuit base. Crush the digestive biscuits and mix them with melted butter, then press this mixture into the base of a rectangular dish. Chill it in the fridge to set. Meanwhile, whip the double cream until soft peaks form, then fold in the condensed milk and lime juice. Pour this creamy mixture over the chilled biscuit base and smooth the surface. Finally, garnish with lime zest and extra lime slices, and chill the dessert for several hours before serving.
Can I Make Mary Berry’s Key Lime Tranche In Advance?
Yes, you can make Mary Berry’s Key Lime Tranche in advance. In fact, it’s recommended to chill it for several hours or even overnight to allow the flavors to meld together and the dessert to set properly. This makes it an ideal choice for preparing ahead of time for gatherings or special occasions.
