What am I doing wrong with my Beurre Blanc? I made my first Beurre Blanc a couple days ago. It got very sour and I had to pour some sugar to sweeten it. I'm almost sure I reduced the wine and the vinegar enough before I started throwing in the butter.

I know I probably made this 2 mistakes:


I didn't measure the exact amount of wine and vinegar. I just put one glass of wine and a little stream of vinegar. 
I used distilled white vinegar, not white wine vinegar.


Are these 2 mistakes what made my sauce sour or there's something else I'm doing wrong here? I really wanna master the Beurre Blanc because I love cooking fish but I've never made a sauce for it. 

Thank you guys in advance.
Julia Child's "classic" recipe for beurre blanc uses quite a lot of butter (3 sticks) to 1/4 cup each of white wine and white wine vinegar (plus shallot and salt and pepper, with a squeeze of lemon to finish).  I suspect that you (a) used too much liquid, and (b) used the wrong vinegar, leading to an overly sour/acetic sauce.