An oil/grease removal assembly includes a container having an inlet to receive effluent from a kitchen sink. A drain connection spaced above the container bottom defines a static water level for contained liquid and connects to a sewer. A baffle extends downwardly below the static water level so water can flow below the baffle to the drain, while retaining floating oil/grease. Means intermittently raise the liquid level in the container above the static water level. Floating oil/grease can flow out through a port when the liquid level in the container is raised above the static water level.