Multiple choice Which factor does not affect the ability of starch to thicken? The size of crystals formed from a solution. The PH level of the food. The proportion of amylose and amylopectin molecules. The serving temperature. Reveal answer Fill a bubble to check yourself A Correct answer Explanation The size of crystals formed from a solution is not a factor in the thickening power of starch. PH level, amylose/amylopectin ratio, and temperature all significantly impact starch gelatinization and thickening.