What Tricks Help Fries Stay Crisp and Separated? Fries often start golden and firm, but can become soft in a few minutes. Moisture and oil interaction cause this. Water inside potatoes turns into steam while cooking. If steam cannot escape, it collects on fries, making them soft. Potato type also affects texture. Starchy potatoes absorb oil differently from waxy ones. Oil temperature plays a major role. Cold oil makes fries absorb more oil,...