Hollandaise and Foaming Hollandaise
This great classic butter sauce from France can be tricky if it gets too much heat, so great care is in order here.
However, since the advent of blenders and processors the risk is not as large as it used to be with hand whisking over hot water. It has to be said that a blender is best, but a processor works well, too. My own problem has always been how to keep it warm, as I always like to make in advance, and overheating will make it curdle. There are two possible answers for this: either use a wide-necked Thermos flask rinsed with boiling water, or to make a lighter, more stable version - Foaming Hollandaise.
The Delia Online Cookery School: You can now watch how to make Hollandaise and Foaming Hollandaise Sauce in our video, just click the image to play.
This recipe is from Delia's Complete How to Cook. Scroll to the bottom of the page to see questions Lindsey has answered on this recipe
To begin place the egg yolks in a small food processor or blender and add some seasoning.
Then heat the lemon juice and white wine vinegar in a small saucepan until the mixture starts to bubble and simmer. Now pour the hot lemon juice mixture in to join the yolks and blend for 30 seconds until thoroughly combined. Then, using the same saucepan, melt the butter over a gentle heat, being very careful not to let it brown. (If your processor lid has a larger feeding hole, cover it with a piece of cling film to prevent the sauce splashing).
When the butter is foaming, switch the processor or blender on once more and pour in the butter in a thin, slow, steady trickle; the slower you add it the better. (If it helps you to use a jug and not pour from the saucepan, warm a jug with boiling water, discard the boiling water and then pour the butter mixture into that first.) When all the butter has been incorporated, wipe around the sides of the processor bowl or blender with a spatula to incorporate all the sauce, you should end up with a lovely, smooth, thick, buttery sauce.
To make the Hollandaise into Foaming Hollandaise:
Whisk the remaining 2 egg whites to soft peaks in a large clean mixing bowl and fold into the sauce immediately. This makes the sauce lighter and it goes further.
Note: this recipe contains raw eggs. It can be kept in the fridge then reheated in a bowl over a pan of gently simmering water or you can even make it ahead and freeze it, unlike Hollandaise which cannot be frozen.