Lemon posset is a British set-cream dessert made from just three ingredients: heavy cream, sugar, and fresh lemon juice. The lemon acid does all the work of setting the cream — no eggs, no gelatin, no special equipment. The honest reason to make it is that it takes about 25 minutes of actual effort and the result genuinely impresses people.
Substitutions that actually work
- Lemon juice: Fresh only. Bottled juice has a flat, slightly bitter edge that becomes obvious in a recipe this simple.
- Heavy cream: Use cream with at least 36% fat. Half-and-half won’t set properly — the fat content is what the acid is working with.
- Granulated sugar: Caster sugar dissolves a little faster but regular granulated works fine at low-medium heat. Don’t swap in powdered sugar; it can make the texture slightly chalky.
- Coconut cream (dairy-free): Full-fat canned coconut cream works, but chill the can first and use only the thick part. The posset will set, though it will taste noticeably of coconut.
Why this recipe works
Two things actually matter here. First, the cream must reach a true simmer — small bubbles around the edge of the pan — before you pull it off the heat. Under-heated cream won’t set firmly enough, no matter how long you refrigerate it. Second, the lemon juice goes in off the heat. Adding acid to actively boiling cream can cause it to break into grainy curds rather than a smooth gel. Stir the juice in while the cream is hot but no longer cooking, whisk until combined, and the proteins and fat will bind into that clean, sliceable texture as it chills.
If something goes sideways
- Posset is still liquid after 4 hours: The cream likely didn’t get hot enough, or the lemon juice measurement was short. Unfortunately this one can’t be rescued once chilled — it needs heat to set. Next time, confirm a visible simmer before removing from heat.
- Grainy or curdled texture: The lemon juice was probably added while the cream was still actively boiling. Straining helps catch surface graininess, but deep curdling means starting over.
- Skin forming on top: Normal if the posset cools uncovered before refrigerating. Press a piece of plastic wrap directly onto the surface before chilling to prevent it.
- Too tart: Lemon acidity varies by fruit. If your lemons are very sharp, pull back to 4 tablespoons of juice next time. Skip the garnish — not worth the extra dish — and let the flavor speak on its own.
- Posset won’t release cleanly from ramekins: Posset is designed to be eaten straight from the serving vessel. If you need to unmold it, run a thin knife around the edge and dip the base of the ramekin in warm water for 10 seconds.
Storage and freezing
Covered tightly with plastic wrap pressed to the surface, posset keeps in the refrigerator for up to 3 days with no loss of texture. It’s an excellent make-ahead dessert — set it the night before and it will be at its best the next day. Freezing is not recommended: the cream separates on thawing and the smooth texture is gone. Once set, don’t leave posset at room temperature for more than 30 minutes, especially in a warm kitchen.
Lemon Posset
Equipment
- Medium saucepan
- Whisk
- Strainer
- Serving glasses or bowls
Ingredients
- 2 cups heavy cream preferably organic for richer taste
- â…” cup granulated sugar
- â…“ cup fresh lemon juice from about 2-3 lemons
- 1 tsp grated lemon zest finely grated
Instructions
- In a medium saucepan, combine 2 cups of heavy cream and 2/3 cup of granulated sugar. Heat the mixture over low-medium heat, whisking occasionally, until the sugar is fully dissolved. The cream should just begin to simmer — small bubbles will form around the edge without boiling.
- Remove the saucepan from heat and stir in 1/3 cup of fresh lemon juice and 1 teaspoon of grated lemon zest. Whisk until completely combined and the mixture starts to thicken slightly.
- Pour the mixture through a strainer into serving glasses or bowls to ensure a smooth texture. Allow to cool slightly before refrigerating.
- Refrigerate the posset for at least 4 hours, or until fully set. The final texture should be smooth and creamy, with a slightly firm consistency.
Notes
- For a unique twist, try infusing the cream with a sprig of rosemary before adding the lemon juice. It adds a subtle herbal note that beautifully complements the citrus.
- If you prefer a less sweet version, reduce the sugar to 1/2 cup.
- For a dairy-free alternative, substitute the heavy cream with coconut cream, though the flavor profile will shift slightly.
Nutrition
Common questions
Can I make lemon posset ahead of time?
Yes — it’s actually better made the day before. The texture firms up fully overnight, and the lemon flavor settles into the cream. Cover each glass with plastic wrap and refrigerate for up to 3 days.
How do I know the posset will actually set?
After whisking in the lemon juice, the mixture should thicken slightly and look a little glossy before you pour it — that’s a good sign the acid is already working. If it looks completely unchanged and watery, your cream may not have been hot enough.
Do I need to strain it?
Yes, strain it every time. The strainer catches zest pieces and any small bits of coagulated cream that form when the lemon hits the hot liquid. Skipping it risks a slightly lumpy texture in the final dessert.
Can I use lime or orange juice instead of lemon?
Lime juice works well and sets at roughly the same ratio as lemon. Orange juice is lower in acid and may not set reliably on its own — if you want an orange flavor, use lemon juice to set the cream and add orange zest for the flavor.
More sweet things to bake
- Strawberry Elderflower Fool
- Lavender Honey Panna Cotta
- Zesty White Chocolate Lemon Truffles
- Tropical Lime Bars with Toasted Coconut Crunch