In my baking I use store brand unsalted butter. I have just switched stores and have found that this new one sputters alot when melted. I believe this is evidence of water content in the butter(though i have never understood this because i thought butter was 100% dairy fat?)Except for the making of puff pastry(I'm guessing here) does the amount of water in the butter- really matter for baked goods? If it does, I'm wondering why the FDA doesn't require that a butter's water content be listed on the packaging. I am more than chemistry-challenged, as you might guess from my baking questions, past and present. Thx much for educating me.