Custard, in common language, indicates a series of egg-based creams, that can have different degrees of thickness and can be prepared using different aromas.
Thicker custards are prepared with the addition of starch (flour or corn flour usually) and, in that case, they should be called pastry cream (creme patissiere in French).
Strictly speaking, custard refers to what the French call Creme Anglaise (English cream), which is what I am going to explain: now we will see the process to create the most basic light pouring custard, using only egg yolks, sugar, milk and vanilla. The ingredients can then be changed to suit our specific needs (replacing the milk, or part of it, with cream to make it richer, or using another aroma instead of vanilla for example), but mastering this process you will get consistent results whatever ingredients you have chosen
- Cut the vanilla pod in half lengthwise and scrap the seeds that are inside using a teaspoon
- Add the vanilla seeds to the milk and heat it up
- As you are heating the milk, whisk the yolks and sugar together using a hand or and electric whisk until the mixture looks pale and fluffy
- Add the hot milk to the yolk and sugar mixture, little by little, stirring constantly to incorporate the milk
- When all the milk has been added, put it back in the pan and heat gently, stirring continuously
- The custard is ready when it covers the back of a wooden spoon (if you check the temperature using a probe, it should be 63C, which is also the temperature that will kill all the harmful bacteria that might be in the egg)
That was a very synthetic way to put it, that might be useful for somebody who already knows how to do it and needs a quick reminder, but that information would not be sufficient for a novice, therefore I’m adding some more info and tips to ensure that the process is understood in depth.
Regarding the vanilla pod, it is quite expensive, so, alternatively, you can use vanilla extract, even though the result will not be exactly the same.
TIP: do not discard the pod after scraping the seeds: if you put it in a jar with plain sugar, you will obtain a vanilla-scented sugar.
Be very careful when you pour the milk into the mixture: if you pour it all at once, the heat will cook the yolks and they will scramble. Pour it very slowly, at least at the beginning, whisking continuously to make sure that the hot milk is dispersed quickly into the mixture; keep whisking until all the milk has been incorporated.
Instead of returning it to the pan, the (still) uncooked cream can be cooked in a bain-marie (a bowl placed over a pan of hot water). This is what I actually suggest if you are inexperienced, as it is a bit more time consuming but reduces the risk of scrambling the eggs. This is how you should do it:
- Heat the water in the pan, making sure it doesn’t boil
- Make sure that there is no direct contact between the hot water and the bowl
- I suggest that you use a metal bowl rather than a glass or ceramic one, since metal is a much better conductor of heat and your custard will be ready more quickly
- I know I’m repeating myself, but stir it continuously until it’s ready and you can take it off the heat