Can I double the recipe for blender hollandaise sauce without harming it? Or do I have to make it twice?

Answer 1

Hollandaise is one of those things that does not double well. Trying to make too much at once, you don't get it hot enough to come out right. Unless of course your recipe is a small one to begin with. I usually whisk mine by hand.
I would say maybe 4-5 egg yolks is the largest batch I would attempt.

Answer 2

Hollandaise sauce is best with a whisk, the ingredients break down in a blender, or you use a stick blender........Jason W