Use room temperature eggs. Cold eggs will often result in mayonnaise that does not thicken. Always add the lemon juice first. Lemon juice helps breakdown the protein in the egg yolks so they emulsify better.

Deselect All. 1 egg yolk* 1/2 teaspoon fine salt. 1/2 teaspoon dry mustard. 2 pinches sugar. 2 teaspoons fresh squeezed lemon juice. 1 tablespoon white wine vinegar

Place the egg and yolk, vinegar, salt, mustard, and sugar in a blender. Turn the blender on and slowly pour the oil in through the lid. Blend until mixture thickens.