I was just throwing together a must for merlot. I got 2 cans of alexander's sun country (is this a good brand by the way?) and I added campden before tannin/pectin/nutrient/energizer...I usually let everything sit for 24hrs then add campden, then wait again before yeast. From what I've read, the campden stops certain things from working at certain times...any thoughts or should I just add everything and wait to add yeast?