A brewing piston for infusion preparation, including a head associated with a filtering element, and a lateral surface having a first gasket in proximity to the head and a second gasket at a distance from the first gasket. The brewing piston includes a first conduit connected to the head and arranged to inject a liquid for infusion preparation, and a second conduit connected to the lateral surface between the gaskets and arranged to inject the liquid between the first gasket and the second gasket during infusion preparation. The piston is arranged to limit or avoid leaks in a machine for infusion preparation. Also included is a machine using the piston and a method of limiting or avoiding leaks in a machine for infusion preparation.