Equipment
Ingredients
Lemon Custard Base
- 4 egg yolks, room temperature
- 120 g granulated sugar
- 80 ml lemon juice, freshly squeezed and strained
- 10 g lemon zest, finely grated, avoiding the white pith
- 1 g salt
Whipped Cream
- 400 ml heavy whipping cream, chilled
- 5 ml vanilla extract
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 262 kcal
- Protein
- 3 g
- Carbohydrates
- 18 g
- Fat
- 20 g
- Fiber
- 0 g
- Sugar
- 17 g
- Sodium
- 67 mg
- Saturated Fat
- 12 g
- Trans Fat
- 1 g
- Monounsaturated Fat
- 6 g
- Polyunsaturated Fat
- 1 g
- Cholesterol
- 154 mg
- Potassium
- 71 mg
- Calcium
- 47 mg
- Iron
- 0.3 mg
- Magnesium
- 5 mg
- Phosphorus
- 65 mg
- Zinc
- 0.3 mg
- Vitamin A
- 240 mcg
- Vitamin C
- 6 mg
- Vitamin D
- 1.3 mcg
- Vitamin E
- 0.7 mg
- Vitamin K
- 2 mcg
- Vitamin B6
- 0.1 mg
- Vitamin B12
- 0.3 mcg
- Thiamin
- 0.03 mg
- Riboflavin
- 0.15 mg
- Niacin
- 0.1 mg
- Folate
- 17 mcg
- Water
- 44 g
- Alcohol
- 0 g
Sources: USDA FoodData Central
Method
Line the 9x5 inch loaf pan with a double layer of plastic wrap, leaving plenty of overhang on the sides. This overhang will be used to lift the frozen dessert out later.
Set up a bain-marie by pouring about 3 centimeters of water into the saucepan and bringing it to a gentle simmer over medium-low heat.
In the heatproof bowl, combine the egg yolks, granulated sugar, fresh lemon juice, lemon zest, and salt. Whisk vigorously until the ingredients are fully incorporated.
Place the bowl over the simmering water, ensuring the bottom does not touch the water itself. Whisk continuously until the mixture thickens, turns pale, and reaches 74°C or 165°F to ensure food safety and create a stable structure.
Carefully remove the bowl from the heat. Whisk for another 2 minutes to release residual heat, then set the bowl aside and let the mixture cool completely to room temperature.
In a separate large mixing bowl, pour in the chilled heavy whipping cream and vanilla extract. Use an electric mixer to whip the cream until medium-stiff peaks form.
Add one-third of the cooled lemon yolk mixture into the whipped cream to lighten the base. Then, gently fold in the remaining lemon mixture using a silicone spatula, using a bottom-to-top sweeping motion to keep the air intact.
Pour the completely folded semifreddo mixture into the plastic wrap-lined loaf pan. Smooth the top with your spatula, then fold the overhanging plastic wrap neatly over the surface to seal out any air.
Transfer the sealed loaf pan to the freezer. Chill for at least 8 hours, or ideally overnight, until the semifreddo is completely solid.
To serve, unwrap the top layer of plastic. Invert the pan onto a chilled serving platter, lift the pan away, and carefully peel off the remaining plastic wrap. Slice portions using a chef knife dipped in warm water.
Chef's Notes
- For the purest and brightest flavor, always use organic lemons. Grate only the outermost yellow skin, as the white pith underneath will introduce an unpleasant bitterness to the custard.
- Chilling both your large mixing bowl and the electric mixer beaters in the freezer for 10 minutes prior to whipping will help the heavy cream whip up significantly faster and hold a stronger structure.
- If you notice tiny cooked egg bits after heating the custard base over the bain-marie, immediately pass the warm liquid through a fine mesh sieve before letting it cool.
- Fold the final mixture with patience. Rushing the folding process will deflate the whipped cream, resulting in a dense, icy block instead of the signature airy, mousse-like texture.
Storage
Freezer: 1 month — Wrap tightly in multiple layers of plastic wrap to prevent freezer burn.
Troubleshooting
Semifreddo is overly icy or crystallized instead of smooth.
Cause: The heavy cream was under-whipped or excess liquid was introduced.
Fix: Cannot be fixed once frozen, but allowing the semifreddo to sit at room temperature for 10 minutes before slicing can improve mouthfeel.
Prevention: Whip the cream to proper medium-stiff peaks so the fat encapsulates the air bubbles, and measure lemon juice strictly.
Cultural Context
Semifreddo translates directly to half-cold in Italian, a nod to its unique texture that feels remarkably soft and creamy even when frozen completely solid. The dessert originated in Italy during the late 19th century as a more accessible alternative to traditional gelato, relying on the high fat content of whipped cream to prevent ice crystals rather than requiring a churning machine. This bright lemon variation specifically highlights the celebrated citrus bounties found along the Amalfi Coast and throughout Sicily.
