The rosenhut sits on a cucurbit in place of a plain domed moor's head, and its whole advantage comes from its shape: rather than a shallow dome, it rises as a tall, narrowing cone. Height alone does most of the work: because the cone's peak sits much farther from the heated liquid below than a shallow dome's peak would, the air around that peak stays noticeably cooler, so vapor reaching the very top of the cone condenses quickly and cleanly rather than lingering as hot vapor near a warm surface. That mattered enormously for distilling rosewater and other delicate botanical essences, since the volatile aromatic compounds that give a flower water its scent break down or scorch if kept too hot for too long, and the rosenhut's cool tip protected them in a way a wider, shallower head could not.
Some versions of the rosenhut added a second, lower spout partway up the cone's height, so that a heavier, less volatile vapor fraction condensing lower down the cone, where it was still relatively warm, could be drained off separately from the lightest fraction still rising to the cool tip, giving the operator a crude but functional way to separate a mixture into two grades in a single pass rather than only one.