Combine egg yolks, lemon juice and water in a container suitable for use with the stick blender, or in a vitamiser. Grind in two turns of white pepper and add a tiny pinch of salt. Blend. Roughly cube the butter and place it into a saucepan; gently melt the butter until foaming or bubbling, but not turning brown. Watch carefully, ensuring it does not brown at all. With the blender still running, add the hot butter, drop by drop to start with, slowly increasing the amount of hot butter as it is incorporated into the egg mixture. Continue to slowly add the melted butter, omitting the milky residue at the bottom of the pot. Taste and adjust the seasonings, adding more salt, pepper or a few extra drops of lemon juice if necessary. The amount of butter you can use when making this sauce in a blender is only half the amount the egg yolks could absorb if you were making the sauce by hand, when 3 egg yolks can take 250g of butter. If you added more butter to the liquidiser than the 150g, the sauce would become too thick. So, to double your amount of sauce, pour it out the container into a bowl or saucepan and beat into it an additional 125g of melted butter, added very slowly. If your Hollandaise sauce refuses to thicken, pour it out into another container, and then pour it back into the liquidising container. Continue to blend whilst adding the mixture drop by drop. As the butter cools, it begins to cream and forms into a thick sauce. If the sauce curdles or separates, slowly add a tablespoon of cold water, drop by drop, blending continuously. * An emulsion is a mixture of two or more unblendable liquids, such as Vinaigrette and Hollandaise sauce. | 
