How can I prevent my Béarnaise sauce from thickening over night? I'm sometimes making my own béarnaise sauce, and it tastes great and has perfect thickness the first day after making it. But whenever I leave leftovers in the fridge over night, the béarnaise gets really thick (like when whipping cream to much).

I'm trying to keep from overcooking my egg yolks, so I don't think that's whats wrong. I follow a pretty classic recipe with taragon, black peppercorns, white wine vinegar, shallots, egg yolks and clarified butter.

Is there a way to keep it from thickening like this when left in the fridge over night?
When the butter cools in the fridge.... It's going to thicken up. I can't see a way around this? When you heat it up again, it should return to consistency...