Noisy Glass Bottles

I always loved the glass bottles in Zelda and I think a lot of people underestimate their usefulness. They were a great game mechanic and I’m pretty sure it’d be impossible to complete the game without them, so this is my homage to them.

I’m also going to take this opportunity to talk about noise in Cycles.
This red potion took 2000 rendering passes (a long time) and is still somehow noisy (most obvious in the shadow underneath the jar).

Does anyone know how to reduce the noise in images rendered in Cycles? Or is the only way to render more and more passes?
I might try giving some other external renderers a try like Yafaray and LuxRender.