Today we're going to make a custard called a "posset".
I learned about this dessert from an article in Cook's Illustrated. A recipe developer named Annie Petito dug up this classic English recipe and painstakingly developed it. (pictured below) I love reading about the lengths that these developers go to. I always walk away confident that I am making the very best version of a recipe.

And this one is no different.
The recipe takes four simple ingredients and creates a rich creamy dessert that is very close in taste and consistency to Key Lime Pie. The bright lemon flavoring pairs perfectly with fresh blueberries. The heavy cream base makes it incredibly decadent. (But worth every calorie.)

This morning I put on my test kitchen hat and came up with a sugar-free version of the recipe. It's a perfectly sweet posset that has only 7g net carbs per serving.
Enjoy!

NOTE: To make this recipe you'll need to reduce your liquid by ⅓. An easy way to do this is to use a ruler. Check the depth of the mixture before you boil it. Calculate ⅔ of that number and mark it on your ruler. Then check back in with your ruler until the liquid hits your mark.
📋 Recipe
Keto Lemon Custard with Blueberries
This is a low carb lemon custard also known as an English "posset".
- Prep Time: 5
- Cook Time: 15
- Total Time: 20 minutes
- Yield: 4 servings 1x
- Category: Dessert
- Method: Stovetop
- Cuisine: English
- Diet: Diabetic
Ingredients
- 2 cups heavy whipping cream
- 6 tablespoon Swerve or equivalent sweetener
- 6 tablespoonsl emon juice (2 lemons)
- 1 tablespoon lemon zest (1 lemon)
- ½ cup blueberries
Instructions
Step 1. Combine cream, sweetener and lemon zest in a medium size saucepan. Measure the depth and calculate ⅔ of that amount. Mark your ruler at the ⅔ line.
Step 2. Bring to a boil over medium heat. Continue to boil, stirring often to dissolve the sweetener. If the mixture begins to boil over, remove from heat and stir. Return to lowered heat. Cook until the mixture has reduced by ⅓ (your marked line). This should take between 8-12 minutes.
Step 3. Remove the saucepan from heat and stir in the lemon juice.
Step 4. Let the mixture cool until a skin forms, about 20 minutes. Strain through a fine-mesh strainer into a bowl and discard the skin and zest.
Step 5. Divide the mixture into 4 ramekins or serving glasses.
Step 6. Refrigerate uncovered, until set, at least 3 hours.
Step 7. Serve with blueberries on top.
Nutrition
- Calories: 431
- Fat: 45
- Carbohydrates: 8
- Fiber: 1
- Protein: 3
Keywords: Low Carb Lemon Custard, Keto Lemon Custard, Low Carb Posset, Keto Posset
If you liked this low carb custard recipe, then you might like my recipes for Panna Cotta, Keto Flan or Egg Custard.
Holly says
I'd never heard of a posset before but I really like it. It really does taste like key lime pie.
★★★★★
EmilyKrill says
Right?
EmilyKrill says
That's what I thought!