He gave Ginny a studious glance, a small smile on his lips as he did so. "Impressive," he complimented quietly. "Although before you should continue with potion making, never base your potions solely upon research. Sometimes one ingredient with another is harmless, but one ingredient with a combination of other ingredients becomes quite dangerous, possibly even lethal. Try them out, first. Test them. Manipulate them, and then actually make the potion." He gave Ginny a solid glance. "That's how you become good at potion-making."
He kept a steady glance toward her, a proud look on his face. "And nonsense, Ginny. This wasn't an easy potion to make. Eight hours to make a potion isn't an easy potion, love. You did well here, actually. Very well, I'd say. Did you write down the manipulated potion, per chance? Step by step how you made it?"