Every time I try to make mayonnaise with a stick blender it fails. That is, using egg yolks only I cannot get the mayo to thicken. I put the yolk in first, add a bit of mustard, vinegar, salt, and then top off with oil. I start the blender at the bottom of the container, go slowly, and gradually pull the blender up to incorporate the oil. But no luck, the stuff stays runny. I've also tried adding the oil in slowly (which shouldn't' be necessary with the immersion blender) but that doesn't help. Once I add a bit of egg white it thickens right up, but I'd like to make it with yolk only.
Who knows what I'm doing wrong?