i have done 3 berliners. the first was lacto pitched first then an ale yeast pitched 3 days later...it wasnt sour enough. the second two were sour mashed and turned out good. i sour mashed the second for 24hrs and the third 48hrs. the last got a 34 score at NHC 2012. in the future i will not sour mash but split the batch and innoculate one with lacto and the other with ale yeast then blend.