How can I rehydrate dried chillies more efficiently? When I make chilli, I use dried ancho and chipotle chillies which I rehydrate in beef stock. However, as they are light, they just float on top of the liquid and so they don't rehydrate very efficiently - one side can still be a little dry.

Is there some way I can ensure even, efficient rehydration?
I had the same problem with floating chillis so I now soak mine in a cafetiere.