Law360, New York ( November 26, 2014, 10:52 AM EST) -- The district court for the Northern District of Illinois recently denied plaintiff's motion for class certification in Langendorf v. Skinnygirl Cocktails, No. 1:11-cv-07060, 2014 WL 5487670 (N.D. Ill. Oct. 30, 2014), calling attention to the ascertainability requirement that plaintiffs must meet in order to certify a class. Although ascertainability is not explicitly discussed in Rule 23, courts have implicitly required that plaintiffs seeking to certify a class must be able to identify a precisely defined class through the use of objective criteria. While this may sound relatively straightforward, that is not always the case. Courts' focus on ascertainability has become an increasingly useful tool for defendants fighting class certification....