The ingredients

• Lemon - for the preparation of this curd, it's required freshly squeezed lemon juice but also its zest, the latter providing the lemon flavor and aromatics.
• Egg - most lemon curd recipes use only egg yolks, but this recipe uses a large whole egg. For the curd to be bright yellow, it is advisable that the eggs have yellow-orange yolks, because, with light yellow yolk eggs, the lemon curd will become paler in color.
• Butter - along with the egg, will give that creamy characteristic of lemon curd and also when cooling will also give consistency to it. Can be used butter with or without salt, but if using salted, always be aware that there are brands with a higher salt content than others (and so it isn't necessary to season with a pinch of salt).
• Sugar - the amount presented here doesn't make it very sweet but just enough to counterbalance the acidity of the lemon; however, you can add a little more sugar, (I use 100gr of a sugar-stevia blend which will be equivalent in terms of sweetness to 200gr of common sugar.)

How to make

• Start by zesting one or more lemons, and then squeeze its juice until the necessary amount is obtained.
• In a bowl, or even directly in a saucepan or casserole, beat the egg along with the sugar, the pinch of salt (if you use unsalted butter, if you use one with salt you can omit the pinch) and the lemon zest.
• Gradually, and always stirring with a whisk, add the lemon juice.
• It is then taken to low heat, stirring continuously until it starts to thicken after about 8 to 10 minutes. The heat should be really low, and the process should not be accelerated because the end result will not have the right texture if the egg cooks too quickly. For me, the most reliable way is to use a cooking thermometer and stir the mixture slowly until it reaches 75ºC.
• Remove the pan or casserole from the heat, add the butter in pieces (to melt faster) and whisk it until completely melted.
• While still hot, the cream is passed through a strainer into a bowl in order to remove the pieces of zest, which has already released all the flavor to the curd and so that the cream becomes thinner and smoother.
• Place a piece of cling film directly on top, so that it touches the surface of the cream (this prevents a skin from forming on top).
• Allow to cool to room temperature and once cold, the plastic can be removed. Then it can be stored in a previously sterilized jar and placed in the refrigerator for the cream to thick (as in puddings).
• The shelf life is about 2 weeks in the refrigerator, but it can also be frozen for future uses.

Lemon curd recipe

1. Beat egg with sugar, and the zest.
2. Gradually add the lemon juice.
3. In a casserole or pan, bring this mixture to low heat, stirring constantly with a whisk.
4. Let it slowly reach the temperature of 75° C, still stirring.
5. Remove from the heat, and add the butter, mixing well until melting completely.
6. With the help of a fine sieve, strain the cream into a bowl.
7. Cover with film, but so that it touches the surface of the cream (so that it has a uniform creamy texture and does not get a thin solid layer on top) and take it to the refrigerator for a few hours.
8. Place in an airtight jar and store in the refrigerator after each use.