Potiron (in French) happens to be slightly flattened. We don't always notice it, but if you observe them well, you will see a blue tint on the stem above the fruit. Their peduncle is closer to a thick cork stopper and gives the impression of being spongy, while that connected to the pumpkin presents a thin, short, hard, and angular appendage. Typically, the potiron's heart is rather spongy, while the pumpkin has a more stringy consistency. Be careful. Squash with soft flesh can make the soup a little watery. Find flawless pumpkins that make a hollow sound when struck. Once cut, make sure the flesh is bright in color and not fibrous.