I love passion fruit so much that in every place I’ve lived and had a garden in California, I grew a couple of vines to harvest my fruit. When we moved from Oakland to L.A., I packed the fruit into a large cardboard box and drove down with it. Passion fruit and passion fruit-flavored desserts like ice creams and chocolate form a big part of my trips to New Zealand, where this tropically scented fruit takes center stage. Simply put, nothing comes close in flavor to this wonderous fruit.Print
- 2 large eggs
- 2 additional yolks
- 1 cup/200 g sugar
- 1 cup/240 ml passion fruit extract
- ½ cup/110 g unsalted butter, cubed and softened to room temperature
- ¼ tsp fine sea salt
- Fill an electric kettle with water and set it to a boil.
- Fill a medium saucepan with about 1 in/2.5 cm of water and bring to a simmer over low heat. Place a large heatproof bowl over the saucepan. The water should not touch the base of the bowl. Place the eggs and sugar in the bowl and whisk using an electric whisk till the mixture thickens and turns pale yellow at about 151F/66C, around 6 to 8 minutes.
- Whisk in the passion fruit juice, butter, and salt over low speed while continuing to heat the mixture. If, at any time, the water in the saucepan gets low, you can add a bit of hot water from the kettle. Whisk the mixture till combined, then switch to a silicone spatula and stir the mixture constantly while cooking. Cook till the mixture thickens at about 165F to 170F/74C to 77C, about 10 to 12 minutes, scraping the sides of the bowl with the spatula. The liquid curd should be very thick like a custard. Coat the back of a spoon with the custard, and draw a line with your finger; the line should stay. Remove and transfer the curd to a container. You can also strain the curd through a fine-mesh sieve lined with cheesecloth to remove any bits. Press a piece of plastic film on the surface and refrigerate for at least 4 hours until chilled. This curd can be prepared and refrigerated for up to 1 week or frozen for 3 months.
- To extract passion fruit juice from the fruit, collect the pulp with the seeds by scooping it out. Place the pulp with the seeds in a blender and pulse on high speed for a few seconds. Then strain the liquid over a medium bowl using a fine-mesh sieve and press to squeeze all the juice out. Discard the pulp in the strainer and use the juice as needed. The black specks of the broken seeds do not bother me in the final curd but if you don’t care for them, strain the mixture through a fine-mesh sieve lined with cheesecloth. You can also perform this at the end once the curd is done cooking when removing any lumps.
- The bowl’s material will affect the rate at which the curd thickens. Skip using a glass or ceramic bowl will take longer to heat than a stainless-steel one.
- Fruit curds are made by applying physical and chemical conditions to denature egg proteins. The heat from the hot water bath and the mechanical whisking of the mixture provide the physical conditions to denature the egg proteins. The acid from the passion fruit pulp provides a low pH which provides the chemical conditions for the proteins in the egg to change their shape and denature. At 151F/66C, egg yolks thicken, and egg whites are tender. On further heating, to about 165 to 170F/74 to 77C, the mixture will begin to thicken visibly, and the curd will be ready. At this temperature, the mixed eggs will thicken, and your curd will be prepared. If you heat it above this temperature, you risk the chance of the egg proteins coagulating and clumping.
- When heating the mixture, it is essential to constantly stir it to ensure even heating and prevent coagulation of the egg proteins.
- Sometimes starch is added as second insurance to thicken egg-based custards (and even curds). I don’t use it in this recipe, but if I did, I would need to heat the liquid to 185F/85C to inactivate the enzyme lysozyme present in egg yolks. This enzyme cuts starch up and will prevent the starch from thickening the liquid.