Anna Louise A good lemon buttercream is one of the most useful things a baker can have completely mastered. I use it on lemon cakes, on vanilla cupcakes, on lemon drizzle traybakes when I want a frosted version, and as a filling between sponge layers.
It is sharp, vivid, and buttery — and it gives any cake it goes on a specifically refreshing quality that makes people reach for a second slice.
The key to a great lemon buttercream — as opposed to a merely acceptable one — is using both the juice and the zest of fresh lemons, being very generous with both, and beating the butter for long enough before the icing sugar goes in.
Lemon extract gives an artificial flavour that fresh lemon juice and zest do not. And butter not beaten for long enough gives a heavy, dense buttercream rather than the light, silky one that makes this frosting specifically good.
This recipe makes enough to fill and top a two-layer 20cm cake or to top twenty-four cupcakes.
Ingredients for Mary Berry Lemon Buttercream
For the Lemon Buttercream
- 250g unsalted butter, softened — at room temperature for at least one hour
- 500g icing sugar, sifted twice — double sifting removes every lump
- Finely grated zest of 3 large unwaxed lemons — gives the vivid fragrance
- Juice of 2 large unwaxed lemons — about 6 tbsp — gives the sharp, vivid flavour
- 1 tsp vanilla extract — rounds the flavour
- Pinch of fine salt — prevents the buttercream from tasting flat and overly sweet
- 1–2 tbsp whole milk — added only if needed to reach the right consistency
How to Make Mary Berry Lemon Buttercream
Step 1 — Beat the Butter
Put the softened butter into a large bowl. Beat with an electric hand whisk on high speed for four full minutes until the butter is very pale — almost white — and genuinely fluffy. This is the most important step in the whole recipe. Four minutes of beating creates the light, airy base that gives the buttercream its silky quality. Under-beaten butter gives a dense, slightly yellow, slightly heavy buttercream.
Set a timer. Do not cut this short.
Step 2 — Add the Icing Sugar
Add the double-sifted icing sugar in three batches — beating well on medium speed after each addition. After the first batch the mixture will look crumbly and dry — this is normal. After the second and third batches it will come together into a thick, pale buttercream.
Step 3 — Add the Lemon and Flavourings
Add the lemon zest, lemon juice, vanilla extract, and salt. Beat on medium speed for two minutes until completely smooth and well combined.
Taste the buttercream. It should be clearly, assertively lemon-flavoured — sharp, fragrant, buttery, and sweet in that order. If the lemon flavour seems mild, add the zest of one more lemon.
Add milk one tablespoon at a time if needed — only if the buttercream seems too stiff to spread or pipe smoothly.
Step 4 — Use or Store
Use immediately for spreading or piping, or store as directed below.
My Top Tips For Best Mary Berry Lemon Buttercream
Beat the butter for the full four minutes. I say this in every buttercream recipe and it is always true. Four minutes of beating butter alone — before the icing sugar goes in — gives the pale, aerated base that makes the difference between a silky, light lemon buttercream and a heavy, dense one. Set a timer and do not cut it short.
Double-sift the icing sugar. A buttercream made with once-sifted or unsifted icing sugar has tiny lumps throughout that are noticeable both in the texture and when piping. Double-sifted icing sugar gives a completely smooth, completely lump-free buttercream.
Use both zest and juice — be generous with both. The zest gives the fragrance and the essential oil that make lemon taste specifically of lemon. The juice gives the sharp, vivid flavour. Together, with three lemons’ worth of zest and two lemons’ worth of juice, the buttercream tastes assertively and beautifully of lemon. Reduced quantities give a mild, slightly disappointing result.
The salt is not optional. A pinch of salt in a sweet buttercream is the detail that prevents it from tasting one-dimensionally sweet. It makes all the other flavours — lemon, butter, vanilla — taste more of themselves.
The lemon juice also adjusts the consistency. Six tablespoons of lemon juice give the buttercream a slightly softer, more spreadable consistency than a standard buttercream made with only milk. This makes it easier to spread on a cake and gives a slightly more fluid piped swirl on a cupcake.
Serving Suggestions
As the filling and frosting for the lemon cake on this site. On top of vanilla cupcakes. On a lemon drizzle traybake for a more generous, frosted version. As a filling in sandwich biscuits.
How to Store Mary Berry Lemon Buttercream
At room temperature: Use within two hours of making for the best piping and spreading consistency. In the fridge: Store in a covered bowl for up to 5 days. Bring to room temperature for one hour and beat briefly before using — cold buttercream is too stiff to spread or pipe smoothly.
In the freezer: Freeze for up to 3 months. Defrost overnight in the fridge, then bring to room temperature and beat briefly.
Mary Berry Lemon Buttercream Recipe
Ingredients
Method
- Beat softened butter alone on high speed for 4 full minutes — until very pale and genuinely fluffy. Set a timer. Do not cut this short.
- Add double-sifted icing sugar in 3 batches — beat well on medium speed after each.
- Add lemon zest, lemon juice, vanilla, and salt. Beat 2 minutes until completely smooth. Taste — season with more lemon zest if needed. Add milk 1 tbsp at a time only if too stiff.
- Use immediately for best consistency or store as directed.
Notes
Frequently Asked Questions
Can I use lemon extract instead of fresh lemon?
Fresh lemon juice and zest give a natural, vivid, specifically lemon flavour. Lemon extract gives a more concentrated but slightly artificial character. Fresh is always better for this buttercream.
Can I make this into a lime buttercream?
Yes — use lime zest and juice in the same quantities. Lime gives a slightly more tropical, slightly more fragrant result that is completely wonderful.
Why is my lemon buttercream too runny?
Too much liquid was added — either the lemon juice was too generous or too much milk was added. Beat in a little extra sifted icing sugar, one tablespoon at a time, until the consistency comes back. Refrigerate for fifteen minutes if it is still soft.
Can I add a few drops of yellow food colouring?
Yes — a tiny amount of yellow gel food colouring gives a pale, vivid lemon-yellow buttercream that looks beautiful on a cake or cupcake.
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