"It's impressive when it works," she corrected, "Novice students make their own potions almost every class. Deviate from the recipe slightly and it's a new variant." Her eyes glanced sideways, watching the Ravenclaw lean towards the cauldron before she finished looking over her list.
"It was the leaves," she decided picking up a dish of sliced rat spleen to add in as well. "The knotgrass leaves, I rolled them enough to crush the edges before adding them. It starts an oxidisation process that is otherwise skipped. Seems it also speeds everything up. Spleen should help," she explained, stirring the potion clockwise twice and then anti-clockwise once more.