Hollandaise sauce originated from 19th century French cuisine, it means Holland-style or from Holland. Most historians agree that it was originally called Sauce Isigny after a town in Normandy known for its butter. During World War I, butter production came to a halt in France and was imported from Holland to supply the demand. The name was changed to hollandaise to indicate the source of the butter and was never changed back.
- 200g salted butter
- 2 egg yolks
- 2 tablespoons lemon juice
- 2 tablespoons white wine vinegar
Melt the butter and leave it for 5 minutes to separate. Place a large pot filled to a third with water on to boil. Choose a stainless steel mixing bowl that sits on top of the pot and place the egg yolks, lemon juice and vinegar into the mixing bowl. Turn heat down to a slow simmer. Gently whisk the yolks in the bowl over the water and they will slowly start to heat and increase in volume.
The purpose of the whisking is not to aerate the mixture so much as to avoid the sabayon catching and ensuring even thickening. You will notice the sabayon becomes a little thicker on the bottom and around the edges. Keep a towel around the outside of the bowl so that you can remove it from the heat if it starts to form lumps from heating too fast.
Whisk until the yolks hold their shape and have the consistency of soft whipped cream. Place the sabayon bowl onto a damp cloth so it won't spin while you whisk. The butter should be well separated now and quite hot. You may need to reheat quickly but not so it boils.
Slowly while whisking, start to pour on the butter keeping a steady stream but keep the stream as thin as possible. Don't add more butter than you can whisk in, if the sabayon is overloaded it will split the mixture.
At first the whisking is quite easey but as the butter is slowly incorporated it becomes a little tougher; add the butter slower at this stage to compensate. As you near the milk solids, be at your most diligent not to add too much as the hollandaise is more likely to split when thick. Slowly pour in the milk solids while still whisking, this will loosen the hollandaise and set the consistency.
Usually adding all the milk solids is the correct amount of moisture that the hollandaise needs, but it can be too much so add slowly to avoid runny hollandaise.
Alternatively, if you have added all the milk solids and it is still thicker than you would like, add a little hot water to compensate. Keep in a warm place covered with cling film until serving time. It will keep safely up to 2 hours before you need it.