Acid-Set Ruby Grapefruit Posset with Fennel-Pine Nut Crunch

Name: Acid-Set Ruby Grapefruit Posset with Fennel-Pine Nut Crunch
Prep time: 15 min
Cook time: 15 min
Total time: 30 min
Yield: 4 servings
Ingredients: 450 g Heavy cream; 120 g Caster sugar; 60 g Ruby red grapefruit juice; 20 g Fresh lemon juice; 10 g Ruby red grapefruit zest; 40 g Pine nuts; 2 g Fennel seeds; 15 g Fruity olive oil; 10 g Toasted sugar or Demerara; 2 g Flaky sea salt

A posset is kitchen magic—heavy cream transformed into a silky, spoonable custard using nothing but heat and acid. We rely on the sharp bite of ruby red grapefruit, backed by a micro-dose of lemon juice to guarantee the set, finishing with a savory fennel-pine nut crunch that honors the two-texture rule.

Theo Glass

April 19, 2026

Prep: 15 minutes

Cook: 15 minutes

easy

dessert

springpossetgrapefruitminimalist+1

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Timeline

3 hours 23 minutes

0m1h2h3h

Prep Citrus

Boil Cream Base

Acid-Set & Steep

Strain & Pour

Chill Possets

Make Fennel Crunch

Garnish & Serve

Ingredients

450 g Heavy cream(Must be at least 36% fat. Do not substitute half-and-half; the fat is what prevents curdling.)
120 g Caster sugar(Superfine sugar dissolves quickly. Regular granulated works in a pinch.)
60 g Ruby red grapefruit juice(Freshly squeezed and strained. About 1/2 of a large grapefruit.)
20 g Fresh lemon juice(Grapefruit pH varies wildly. Lemon juice is our insurance policy for a flawless set.)
10 g Ruby red grapefruit zest(Microplaned carefully to avoid the bitter white pith.)
40 g Pine nuts(Our buttery, fatty base for the crunch.)
2 g Fennel seeds(Lightly crushed. The one-contrast upgrade that makes the grapefruit sing.)
15 g Fruity olive oil(A grassy, peppery finishing oil.)
10 g Toasted sugar or Demerara(For structural snap.)
2 g Flaky sea salt(Maldon preferred.)

Instructions

1
Wipe your counter. Gather your ingredients. In a small bowl, whisk together 10g ruby red grapefruit zest, 60g ruby red grapefruit juice, and 20g fresh lemon juice. Set aside. This blend is our engine; the lemon ensures we hit the precise pH required to coagulate the cream without splitting it.
5 min
Tip: Grapefruit alone is a gamble for acid-setting. Precision is freedom—weigh the juices.
2
In a medium saucepan over medium heat, combine 450g heavy cream and 120g caster sugar. Stir gently until the sugar dissolves. Once it reaches a rolling boil, set a timer and let it boil for exactly 3 minutes, stirring constantly so it doesn't boil over. This reduces the water content and concentrates the fat.
8 min
Tip: Watch the pot closely. Cream loves to climb the walls of a pan and make a mess.
3
Remove the pan from the heat. Let it sit for exactly 60 seconds (we want the temperature around 90°C/195°F). Pour in the citrus mixture and whisk slowly and deliberately. You will feel the liquid thicken almost immediately. Let it steep undisturbed for 5 minutes.
6 min
Tip: Do not add the acid while the cream is actively boiling, or it will violently curdle instead of smoothly setting.
4
Pour the mixture through a fine-mesh sieve into a spouted measuring jug. We are extracting the essential oils from the zest but discarding the solid pieces to maintain absolute silkiness. Divide the mixture evenly between 4 small glasses or ramekins.
4 min
Tip: Label the bottom of the glasses with a piece of painter's tape if you're making these for a specific future date.
5
Carefully transfer the glasses to the refrigerator. Let them cool. Future you deserves a perfectly unbroken set, so don't jostle them. They need at least 3 hours to chill completely, though overnight is ideal.
180 min
Tip: Do not cover them with plastic wrap until they are completely cold, otherwise condensation will drip onto the surface.
6
While the possets chill, make the crunch. In a dry skillet over medium-low heat, toast 40g pine nuts and 2g fennel seeds until golden and fragrant, about 4 minutes. Remove from heat immediately. Toss the warm nuts and seeds with 15g fruity olive oil, 10g toasted sugar, and 2g flaky sea salt. Let it cool to room temperature.
10 min
Tip: The residual heat of the pan will keep toasting the nuts. Get them out of the pan and into a bowl quickly.
7
Before serving, spoon the cooled fennel-pine nut crunch over the set possets. The dense, buttery snap of the pine nuts and the herbaceous hit of fennel provide the necessary contrast to the rich, sharp citrus cream.
2 min
Tip: Only add the crunch right before serving to preserve its texture.

Chef's Notes

Contrast is the secret ingredient here. We’re taking an old-school British technique, stripping out the fuss, and applying modern pantry staples. The fennel seed acts as a bridge between the bitter grapefruit and the rich dairy. Remember, we're not adding steps—just improving decisions. Weigh your cream, respect the 3-minute boil time, and trust the chemistry.

Frequently Asked Questions

How long does Acid-Set Ruby Grapefruit Posset with Fennel-Pine Nut Crunch take to make?

Acid-Set Ruby Grapefruit Posset with Fennel-Pine Nut Crunch takes about 30 minutes total. That includes 15 minutes of prep and 15 minutes of cooking.

How many servings does this recipe make?

This recipe makes 4 servings.

What skill level is needed for Acid-Set Ruby Grapefruit Posset with Fennel-Pine Nut Crunch?

This recipe is rated easy — it's beginner-friendly and straightforward.

What ingredients do I need for Acid-Set Ruby Grapefruit Posset with Fennel-Pine Nut Crunch?

The main ingredients are: Heavy cream, Caster sugar, Ruby red grapefruit juice, Fresh lemon juice, Ruby red grapefruit zest, Pine nuts, Fennel seeds, Fruity olive oil, Toasted sugar or Demerara, Flaky sea salt.

What type of meal is Acid-Set Ruby Grapefruit Posset with Fennel-Pine Nut Crunch?

Acid-Set Ruby Grapefruit Posset with Fennel-Pine Nut Crunch is categorized as: dessert.

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