  Bubbles at a free surface surface usually burst in ejecting myriads of
droplets. Focusing on the bubble bursting jet, prelude for these aerosols, we
propose a simple scaling for the jet velocity and we unravel experimentally the
intricate roles of bubble shape, capillary waves, gravity and liquid
properties. We demonstrate that droplets ejection unexpectedly changes with
liquid properties. In particular, using damping action of viscosity,
self-similar collapse can be sheltered from capillary ripples and continue
closer to the singular limit, therefore producing faster and smaller
droplets.These results pave the road to the control of the bursting bubble
aerosols.
