With citrus fruit now in season, one way of preserving them is in a curd - a custard-like jam that keeps in the fridge for about 4 weeks and in the freezer for about a year. It requires eggs and butter, making it rich and creamy, but less long-lived. I have experimented with making various curds at different times, and enjoy them all. Grapefruit curd is a particular favourite. It is also something that always seems like it will be more complicated and difficult than it is. Some recipes call for egg yolks, others for whole eggs. I've done it with both in the past and both work. The curd is maybe a little richer when made with egg yolks rather than whole eggs though. This time, going away a day later for Christmas, I didn't want extra egg whites hanging around, so I used whole eggs. Feel free to substitute though. As you cook until it thickens, I don't tend to change the proportions much, the curd just thickens faster with egg yolks than whole eggs.
1 c + 3 tbsp sugar (250g)
1 1/8 c butter, diced (250g)
Juice of 1 1/2 grapefruits, reduced by about 1/3
Zest of 2 grapefruits
1) Place a heatproof bowl over a saucepan of simmering water, making sure that the bottom of the bowl doesn't touch the water, forming a Bain Marie. In this, whisk together the sugar and eggs until uniformly combined.
2) Add the zest and the juice and whisk well. Add the butter a cube or two at a time, waiting to add the next cube until the previous ones have mostly melted. Continue whisking and adding butter cubes until all the butter is added and melted, and the curd begins to thicken.
(Optional extra step for a smoother curd: Strain the curd when it has begun to thicken, removing the zest and any other bits. I find this unnecessary and don't mind encountering bits of zest, but the choice is yours).
3) Meanwhile, sterilise jars in boiling water for 15 minutes. When the curd has begun to thicken, spoon the hot curd into freshly boiled jars and seal immediately, making sure the rims of the jars stay clean. As the curd cools, it will seal the jars. ( I needed three jam jars for this quantity of curd).
The curd should keep in the fridge for about 4 weeks or in the freezer for about a year. Once opened, be aware that it is made with eggs, so consume it relatively quickly. I am pleased with how this turned out, and am planning on conserving more citrus this way as they come into season, so stay tuned for any variations!