Why do Vanilla Shakes mix so terribly compared to Chocolate?

[SaladFork]

I use ON Gold Standard 100% Whey... Vanilla Ice Cream. Try some, you will LOVE it, it's the only shake I have had that mixes in the shaker, no spoon scooping or lumps. Don't need a blender and it mixes light. Trust me, it will change your mind about vanilla shakes.

 

[1999TL]

EAS mixes horrible. I dont think it's instantized like ON's. BSN's True mass, vanilla ice cream, mixes great or me as well.

I started off with chocolate and now I find vanilla much more enjoyable.