Melt butter in a heavy saucepan over moderate heat.
Remove pan from heat and let stand for 3 minutes.
Skim foam from top of melted butter.
In a separate bowl whisk together the yolks, lemon juice, and water in another heavy saucepan until frothy.
Set pan over low heat and whisk constantly and vigorously until yolks are pale yellow and slightly thickened about 3 to 4 minutes.
Remove pan from heat and gradually whisk in melted butter:
drop by drop for first third of butter,
then 1 teaspoon at a time for second third
and 1 tablespoon at a time for final third, leaving milky solids in bottom of pan.
Whisk in salt and white pepper.