This is the second time I have attempted to make mayonnaise and it just won't thicken. It's not a case of a broken emulsion-- I just get a frothy liquid.
I started by tempering the egg over a bain marie with some dry mustard. When it gets thick and pale, I start to incorporate the oil drop by drop. I'm 4 ounces of oil in (1 egg) and it's still just liquid. On this second attempt I whisked some water into the egg (about half a T) before proceeding with the oil. Any idea what I'm doing wrong?