FIELD: methods in organic chemistry. SUBSTANCE: aqueous solution of aspartame or its salt at pH below 3.0 is prepared, neutralized to higher pH value, and mechanically agitated to achieve homogeneity resulting in forming crystals. Mechanical agitation of neutralized and homogenized solution is terminated at least 1 s before formation of crystals becomes visually detectable. According to invention, aqueous solution of aspartame initially prepared has pH higher than 0.5 and aspartame concentration in it ranges from 1.5 to 20.0 wt %. Amount of aspartame taken for preparing solution is such that, after neutralization of its solution, absolute aspartame supersaturation 1.0-15.0 wt % where attained. For neutralization, sodium or ammonium hydroxide aqueous solution are utilized. EFFECT: enhanced efficiency of procedure. 20 cl, 2 tbl
