The effect of the whey protein isolate (WPI) concentration on the sol-gel-sol transition in alkali cold gelation was investigated at pH 11.6-13 using oscillatory rheometry. The elastic modulus increases quickly with time to reach a local maximum (G'(max))followed by a degelation step where the modulus decreases to a minimum value (G'(min)). Depending on the pH, a second gelation step will occur. At the end of the first gelation step around G'(max) the system fulfilled the Winter-Chambon criterion of gelation. The analysis of the maximum moduli with the protein concentration shows that (i) there is a percolation concentration above which an elastic response is observed (similar to 6.8 wt %) (ii) there are two concentration regimes for G ''(max) and G ''(max) above this concentration, where we have considered power-law and percolation equations (iii) there is a crossover concentration between the two regimes (at similar to 8 wt %) for both G'(max) and G ''(max) when both moduli are equal, and this value is constant under all conditions tested (G'(max) = G ''(max) approximate to 4 Pa). Therefore. alkali cold gelation is better represented using two concentrations regimes than one. as observed for other biopolymers.