Europa, one of Jupiter’s moons, has an icy surface that contains chemicals like oxidants, which could be important for supporting life. For Europa’s deep ocean to be habitable, some of these surface materials need to make their way through the ice and into the ocean below. This study looks at how that delivery happens in two steps: first, materials move from the surface into the ice shell, and then they melt through the bottom of the ice into the ocean. If Europa has gone through periods of strong tidal heating—caused by its gravitational interactions with Jupiter—then the bottom of the ice could have melted more in the past, allowing more materials to reach the ocean during those times. We find that during quiet, cooler periods, only small amounts of oxidants reach the ocean. But during warm periods with more melting, huge amounts—up to a trillion moles per year—could be delivered. These bursts could dramatically change the ocean’s chemistry and the amount of energy available for life. This research helps us better understand how Europa’s ocean might shift over time, and how such changes affect its ability to support life.