Device having a cover to be positioned on a vessel with an interior wall. A shaft extends through a transverse passageway in the cover. A basket for holding a flavoring substance is mounted to the end of the shaft. The basket can thus be raised and lowered within the vessel through action of the shaft. A continuous lip of flexible polymer surrounds the periphery of the basket, for engagement with the interior wall of the vessel. With flavoring substance in the basket, liquid is poured into the vessel in such a way as to retain air in the space between the basket and the bottom of the vessel. The basket is pushed downwards, causing at least part of the air retained in the space between the basket and the bottom portion of the vessel to displace the flavoring substance while the air rises within the vessel, resulting in improved infusion of the flavoring substance.