Sentence:  A less risky method is to lift your whisk or beater to check the condition of the <WSD>peaks</WSD> of the egg whites; the foam should be just stiff enough to stand up in well-defined, unwavering <WSD>peaks</WSD>. 
Meaning of the word marked with <WSD> tags:  A point; the sharp end or top of anything that terminates in a point; as, the peak, or front, of a cap.