Originally Posted by gfunkdave

For some reason it hardens on the blender but stays saucy in the pot (or in tupperware in the fridge), though it does thicken as it cools. Mystery of chemistry.

Hmm to be honest I have never made nacho cheese sauce but I do this same thing to make mac and cheese (adding another cup of milk or half and half in addition to the cup of white wine I start with, actually) and it is equally creamy and cheesy. I suspect with only a cup of liquid it will be pretty satisfyingly cheesy. Perhaps equal parts cheddar and gruyere, or all cheddar to start. It lends itself to experimentation. You do need some liquid to give the sodium citrate something to dissolve in.

edit: the only thing not to experiment too much with is the ratio of cheese to sodium citrate, which should be 8 oz cheese : 1 tsp sodium citrate. If it gets lumpy you need either a little more sodium citrate (a little goes a looong way) or a little more liquid, or both.