In a small bowl, beat together egg yolks, salt, mustard, sugar, pepper, and 1 teaspoon lemon juice, until very thick and pale yellow.
Add 1/4 cup oil, drop by drop, beating vigorously.
Beat in 1 teaspoon each of lemon juice and hot water.
Add another 1/4 cup oil, a few drops at a time, beating vigorously.
Beat in another teaspoon each lemon juice and water.
Add 1/2 cup oil in a fine steady stream, beating continuously, then mix in remaining lemon juice, water, and oil.
Cover and refrigerate.