What’s in a curd?
In pastry a curd refers to a cooked sauce comprised of a citrus or fruit juice, eggs, sugar, a thickening agent like cornstarch and butter.
Curds are used in in a wide variety of desserts from pies, to fillings for cakes and pastries, and even as an accompanying sauce for pastries like scones.
Since most curds use a citrus juice as the base curds are generally not overly sweet. There is wiggle room to play around with ratios and tweak it according to your own taste if you prefer something a little sweeter, but personally I like a curd that is more on the tart side.
They are relatively easy and quick to make and require very little equipment or know how. Basically if you are able to whisk then you can make a curd.
And how do you make this delightfully tangy sauce? Let’s find out. For this recipe we will be making a classic lemon curd.
Like I said you don’t need all that much stuff.
- A large mixing bowl
- Wide mouthed pot
- 1/2 cup of lemon juice – fresh squeezed please (approximately 4 lemons)
- 1/2 cup sugar
- 2 whole eggs, plus 2 yolks (be sure to reserve your egg whites in a plastic container should you want to make a lemon meringue pie)
- 1 tbsp cornstarch
- *option to use another starch like Tapioca starch or Potato starch in case you prefer not to use cornstarch
- 1/2 cup unsalted butter, room temp, cut into chunks
- Fill your large pot about 1/3 of the way with water and bring it to a simmer on a medium heat.
- In your large mixing bowl, first combine the sugar, eggs and egg yolks, and cornstarch, mixing until smooth. The add in the lemon juice and mix until there are no lumps.
- Place your bowl on top of your simmering pot (a.k.a Bain Marie, a.k.a Double Boiler) and whisk the liquid continuously until the liquid thickens.
This will happen in several stages:
First a thin foam will appear on the surface of the liquid.
Next the foam will get thicker and the liquid beneath it will also get thicker.
Eventually, the foam will dissipate and the liquid will transform from thin and semi-transparent to thick opaque pale yellow curd.
- Once that has happened, give your curd a little taste to make sure you don’t taste any raw starch. The curd should taste lemony, not starchy.
- When it’s ready, off the heat, gradually whisk in the chunks of butter. This addition of fat is done gradually so as to create an emulsion or a homogenous mixture where the fat incorporates into the mixture evenly. Adding too much butter too fast and you could end up with a broken sauce where that the fat sort of stays on top rather than blending in.
- You want to whisk each addition of butter in until all the chunks are melted and blended in.
How to Store
You can either transfer your finished curd to a cool storage container or keep it in its bowl depending on how soon soon you want to use it.
Whichever vessel you chose, you have to first let the curd cool completely before refrigerating it.
You also need to prevent a skin from forming. A skin in pastry is just what it sounds like. Sometimes sauces or creams form a thin skin-like layer on their surface which can’t really be used. To avoid that, all you have to do is put a small piece of plastic wrap directly on the surface of your curd and let it cool.
Once it has cooled, you can put it in the fridge to let it set or firm up completely.
Sauces like curds, creams etc need to set in order to use them as fillings. In their warm state they are too runny to hold their shape. Once they’ve cooled however you can scoop them, spread them or pipe them into whatever pastry item you’re making.
* In a curd, that is one of the functions of the butter. Not only does it add a richness to the spread, it also cuts the acidity of the citrus and serves to firm up the mixture once its cooled.
Ideas for Where to Use it
Make a Lemon Meringue Pie: continue reading How to Make a Swiss Meringue in my series for how to make a Lemon Meringue Pie.
Fill a cake or cupcakes:
Curd can be used as a filling for cupcakes, or to fill in between a layer cake. I recommend pairing it with a vanilla cake.
Make a Triffle:
Take a pretty glass serving bowl, stemmed bowl or even mason jar. Cut up some homemade or store-bought cake into slices or chunks. Layer your cake and lemon curd to the top. You could also throw in some fresh berries.
I love lemon curd, or any curd for that matter, but it’s a simple minimal ingredient recipe that takes no time at all to make, and it packs a real punch in terms of jazzing up something plain. It also has an air of sophistication. A curd? so fancy. You are sure to impress anyone with your confection just with a little bit of curd.