So I did the quick souring method as I read on zymurgy and some forums. 2 liter starter with some grains kept at 100-120 F for 3 days, then put that in the wort and kept at around 100F. Its been 2 days right now and it seems like there's a 3/4'' krausen on top of the wort, not a pellicle, it looks more like a normal yeast krausen, and there's a lot of airlock activity. Is this normal?. I took a sample, and the pH is down to 3.9, and gravity is down from 1.055 to 1.044. It smells kinda like sauerkraut, and tastes somewhat sweet and sour, pretty nice actually. Would the beer be noticeably sour if I boil, chill and ferment normally at this pH? Or should I wait for the pH to drop further? Also, should I boil or just pasteurize?