I'm working on my first sour, and it's been a hell of a ride. I pitched lacto, but didn't get much acid. I pitched brett and didn't get much funk. So I pitched a few pounds of raspberries to put come acidity in this thing. A couple weeks later, I'm starting to get this stringy growth where the floating berries meet the neck. Is this what I've been trying to get all along, or is this something unwanted that the raspberries put in my beer?