How do you thicken already made lemon curd?

Lemon curd is a delicious spread that can be used in a variety of baked goods and desserts. It has a bright, tart lemon flavor and a rich, velvety texture. However, sometimes lemon curd can turn out thinner than intended. Luckily, there are a few easy methods to thicken up lemon curd after it has already been made.

Using Cornstarch or Arrowroot

One of the simplest ways to thicken lemon curd is by whisking in a slurry made with cornstarch or arrowroot powder. Here’s how:

1. In a small bowl, whisk together 1-2 teaspoons cornstarch or arrowroot powder with 1-2 tablespoons cold water until smooth.
2. Bring the lemon curd to a simmer in a saucepan over medium heat. Remove from the heat.
3. Gradually whisk the cornstarch or arrowroot slurry into the hot lemon curd until fully incorporated.
4. Return the pan to medium-low heat and cook for 1-2 minutes, stirring constantly, until slightly thickened.
5. Remove from heat and let cool before using.

The cornstarch or arrowroot powder molecules will absorb moisture and thicken up the lemon curd nicely without altering the flavor. Arrowroot may result in a slightly clearer, glossier texture.

Simmering

For a low effort method, you can simply simmer the lemon curd for a little longer to thicken it up:

1. Pour the lemon curd into a saucepan over medium heat.
2. Bring to a gentle simmer, stirring frequently.
3. Allow to simmer for 2-5 minutes, until slightly reduced and thickened.
4. Remove from heat, let cool, and refrigerate.

The extra simmering evaporates some of the moisture content and concentrates the flavor. Be careful not to overcook, as this can cause the curd to separate or curdle.

Adding Egg Yolks

Extra egg yolks can be whisked into lemon curd to create a richer, denser texture. Use this method cautiously, as too many yolks may overwhelm the lemon flavor. Here’s how to do it:

1. In a small bowl, whisk together 1-2 egg yolks.
2. In a separate bowl, stir together 1/4 cup of the cooled lemon curd.
3. Gradually whisk the lemon curd mixture into the egg yolks to temper them.
4. Pour the egg yolk mixture back into the remaining lemon curd.
5. Whisk thoroughly to incorporate.
6. Return to the saucepan and cook over medium-low heat until thickened slightly, about 2 minutes.

The added yolks act as a natural thickener. Just take care not to let the mixture boil, as this can cause curdling.

Mixing in Mascarpone

For a creamy, silky twist, try mixing in some mascarpone cheese. The high-fat mascarpone will add delicious richness and body.

1. Allow lemon curd and mascarpone to come to room temperature.
2. Measure out 1/4 to 1/3 cup mascarpone for every 1 cup of lemon curd.
3. In a mixing bowl, beat the mascarpone lightly with a spoon until smooth.
4. Add the lemon curd and fold together gently until uniform.
5. Refrigerate until set, about 2 hours.

Taste and adjust the amount of mascarpone to your desired thickness. Too much can mute the bright lemon flavors.

Whipping in Heavy Cream

For a lightened, spreadable lemon curd, try folding in some whipped heavy cream. Here’s how simple it is:

1. Whip 1/2 cup cold heavy cream to soft peaks.
2. Fold the whipped cream into 1 cup of lemon curd gently until fully incorporated.
3. Refrigerate for at least 30 minutes before using.

The air incorporated into the whipped cream will add stability and body. You can use more or less cream depending on how thick you want the curd.

Mixing in Butter

If your curd is still too thin, stir in a tablespoon or two of room temperature butter. The fat content will help thicken things up.

1. Allow lemon curd to cool slightly off heat.
2. Stir in 1-2 tablespoons of softened, room temperature butter.
3. Mix thoroughly until the butter is fully incorporated.

A little extra butter can go a long way in improving the consistency of lemon curd. Just avoid over-softening it or the curd may become greasy.

Straining Out Excess Moisture

For curd that is very loose, try straining out some of the excess moisture:

1. Set a fine mesh strainer over a bowl.
2. Pour the lemon curd into the strainer.
3. Gently press the curd against the strainer using a spoon or spatula. This will force out some of the excess liquid.
4. Discard the strained liquid. Transfer the thickened curd to an airtight container.

Straining is best for curd that is very thin, as it can result in some loss of yield. But it’s an easy way to quickly concentrate the texture.

Adding Gelatin

For a curd with an even thicker, sliceable texture, gelatin can be incorporated:

1. Sprinkle 1 teaspoon gelatin powder over 2 tablespoons cold water. Allow to soften and bloom for 5 minutes.
2. Heat the lemon curd gently over medium-low heat until hot, but not boiling.
3. Add the bloomed gelatin and stir continually until fully dissolved, about 2 minutes.
4. Remove from heat, transfer to a container, and refrigerate until set, 1-2 hours.

The gelatin will give the curd more structure, allowing it to firm up for slicing or shaping. Start with a small amount and add more gelatin if needed.

Using Lemon Curd Powder

For a quick fix, lemon curd powder can instantly thicken up runny curd. Here’s how to use it:

1. Measure your quantity of lemon curd. For every 1 cup of curd, use 1-2 teaspoons of powder.
2. In a bowl, mix the powder with a little lemon curd to form a smooth paste.
3. Gradually whisk the paste into the remaining lemon curd until well blended.
4. Let sit briefly until thickened.

Lemon curd powder is a convenient instant thickener. But use a light hand, as too much can make the curd gummy.

Cooking Down in a Double Boiler

One of the most reliable methods is to cook the curd down further in a double boiler:

1. Pour the lemon curd into the top pot of a double boiler.
2. Fill the bottom pot with an inch or two of gently simmering water.
3. Cook the curd over the double boiler, stirring regularly, until thick enough, 15-30 minutes.
4. Remove from heat and let cool completely before using.

The indirect gentle heat prevents scorching while evaporating moisture. Cook and stir patiently until the curd is reduced down to the ideal thick, spreadable texture.

Conclusion

Loose lemon curd can be easily remedied with a few simple tricks. Cornstarch, extra cooking, dairy, and other thickeners can all help achieve a richer, more velvety texture. With the proper adjustments, thin lemon curd can be transformed into a spreadable delight. Just be careful not to over-thicken, as this can cause unpleasant gumminess. With a little finessing, you can turn runny curd into rich, luscious lemon perfection.