Mary Berry​ Lemon Posset Recipe

Mary Berry Lemon Posset is a classic British dessert. This three-ingredient treat combines double cream, caster sugar, and fresh lemon juice into a smooth, set cream that is refreshing and sharp.

If you do nothing else, watch the clock when the cream starts bubbling. That’s the difference between a liquid mess and a firm set. You need a full three minutes of boiling to change the structure of the cream so the lemon juice can do its job.

The lemon zest is doing more work than you’d think. Without it, the flavour feels flat and lacks that sharp citrus punch. I usually leave the zest to steep for the full fifteen minutes because it makes the final result much brighter. It’s the easiest dessert I know that still manages to impress people at a dinner party. Just make sure your lemons are room temperature before you start so you get every bit of juice out of them.

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Mary Berry Lemon Posset Ingredients

• 600ml (1 pint) double cream
• 150g (5oz) caster sugar
• 2 large lemons, zest and juice

How To Make Mary Berry Lemon Posset

1. Heat the cream and sugar: Pour 600ml (1 pint) of double cream into a large, wide-based saucepan to allow for expansion. Add 150g (5oz) of caster sugar and place the pan over a low heat on the hob. Stir the mixture gently with a wooden spoon until you can no longer see or feel any sugar granules at the bottom. Make sure the sugar is fully dissolved before you attempt to increase the temperature. Keep the heat low so the cream doesn’t start to discolour or scald before the sugar has a chance to melt.
2. Boil the mixture: Increase the heat to medium-high until the cream reaches a vigorous, rolling boil that doesn’t subside when stirred. Start a kitchen timer for exactly 3 minutes and keep the liquid bubbling steadily throughout this time. Watch the pot closely to make sure the cream does not rise up and spill over the edges of the pan. Move the spoon across the base of the pot every 30 seconds to prevent the sugar from sticking. The cream will rise quite high in the pan, so stay close and be ready to lift it off the heat if it looks like it might overflow.
3. Add the lemon: Remove the saucepan from the heat immediately once the three minutes are up. Pour in the juice from 2 large lemons and stir in all the finely grated zest using a whisk or spoon. You should see the mixture change consistency and become slightly thicker as the lemon acid reacts with the hot fat in the cream. Use a balloon whisk to make sure the juice is fully incorporated into the fat of the cream for an even set.
4. Let it infuse: Place the pan on a heatproof mat and leave the mixture to sit undisturbed for 15 minutes. This pause is necessary to let the lemon zest steep and release its aromatic oils into the cream. Do not be tempted to stir or move the pan during this stage of the process. This rest period allows the heat to extract the maximum flavour from the lemon zest without the mixture becoming too cold to pour.
5. Strain and pour: Set a fine-mesh sieve over a clean pouring jug and carefully empty the saucepan through the mesh. Press down on the zest with a spoon to get every drop of flavoured cream out before discarding the solids. Carefully pour the smooth, strained liquid into 6 small ramekins or glasses, making sure you divide the mixture equally. Wipe the rim of the glasses with a bit of kitchen roll if you spill any to keep the presentation tidy.
6. Chill until set: Let the glasses cool on the counter for a few minutes before moving them into the refrigerator. Leave them to chill for at least 4 hours until the centres are completely cold and firm to the touch. Cover the tops with clingfilm if you are leaving them overnight to prevent a skin from forming on the surface. Do not put the glasses in the fridge while they are still steaming hot, as this can raise the temperature of your other food.
7. Serve: Remove the possets from the refrigerator right when you are ready to put them on the table. The dessert should be served very cold and should hold its shape well on a spoon. Serve each portion as it is or with a thin, crisp biscuit to add a bit of texture to the dish. You can grate a tiny bit of extra lemon zest over the top at the last second to give it a fresh citrus scent.

Recipe Tips

• Use a large pan. Double cream expands quickly when it boils and can easily spill over the sides of a small pot. A wide-based pan gives you more control and prevents a messy hob from burnt sugar and cream.
• Roll your lemons. Press the fruit against the counter with your palm before cutting them to release more juice. You need about 75ml (3fl oz) of liquid for the cream to set properly, so use three lemons if your fruit feels hard or small.
• Always sieve the liquid. Even if you like the look of zest, the texture of a posset should be completely smooth. Passing it through a fine mesh ensures there are no chewy bits in the finished dessert, which can ruin the experience of the velvety cream.
• Start the timer correctly. Wait until the mixture is bubbling vigorously across the whole surface before you begin the three-minute countdown. If you stop too early, the chemical reaction between the acid and the fat won’t happen and the cream won’t thicken into a solid mass.
• Prepare the day before. These keep well in the fridge for up to two days and often taste better after a long chill in the refrigerator. Cover each ramekin tightly with clingfilm to prevent the cream from absorbing other food smells like onions or cheese.
• Pick heavy ramekins. Using ceramic or thick glass dishes helps the posset stay cold once you take it out of the fridge to serve. Thin plastic containers won’t hold the temperature as well, causing the dessert to soften too quickly at the dinner table.

What To Serve With Lemon Posset

A buttery shortbread biscuit is the traditional partner for this sharp dessert because the sweetness cuts through the citrus. You could also use ginger nuts or almond tuiles to add a bit of crunch that contrasts with the smooth cream.

Fresh raspberries, blackberries, or blueberries provide a nice colour contrast when scattered on top just before serving. A small dollop of whipped cream or a sprig of fresh mint makes the presentation look finished for guests.

How To Store Lemon Posset

Fridge

Keep these in the coldest part of the fridge at all times until you are ready to eat. Cover them with clingfilm to keep the surface from drying out or forming a tough skin. They will stay fresh and hold their texture for up to 3 days if kept cold.

Reheat

Do not try to reheat this dish under any circumstances. The heat will break the set and turn the firm posset back into a thin, oily liquid. It is meant to be eaten chilled directly from the refrigerator to maintain its structure.

Freeze

This dessert does not freeze well because of the high fat content in the double cream. The structure often separates during the defrosting process, leaving you with a grainy and watery mess. It is best to make it fresh and eat it within a few days.

Mary Berry Lemon Posset Nutrition Facts

Per serving (1 of 6):

• Calories: 480
• Protein: 2g
• Fat: 45g
• Carbohydrates: 20g
• Sugar: 20g
• Sodium: 15mg

Estimated. May vary based on ingredients and cooking methods.

FAQs

Why didn’t my Mary Berry Lemon Posset set?

This usually happens if the cream wasn’t boiled for the full 3 minutes or the lemons weren’t juicy enough to provide the necessary acid. Both elements work together to thicken the fat in the double cream into a solid state.

Can I use single cream instead of double cream?

No, single cream does not have a high enough fat content to create a solid set with the lemon juice. You must use double cream to get the right thick and creamy texture.

Can I use the Mary Berry Lemon Posset method with limes?

Yes, you can substitute the same amount of lime juice and zest for a different citrus flavour. Just keep in mind that limes are often smaller, so you might need three or four of them to get enough juice.

Can I whisk the mixture instead of boiling it?

No, the cream needs to reach a specific temperature and boil for several minutes to change its chemical structure. Simply whisking the ingredients together will leave you with a thin, liquid sauce that never firms up.

How long does it take for the posset to firm up?

It takes at least 4 hours in a cold fridge, but leaving it overnight is the safest way to ensure it has fully set. The middle needs to be completely cold to hold its shape when you dig in with a spoon.

Try More Recipes:

• Mary Berry Lemon Meringue Pie​ Recipe
• Mary Berry Lemon Curd Recipe​
• Mary Berry Mince Pies​ Recipe