A method for continuously washing packed red blood cells comprising: (a) connecting a wash solution container to a wash solution line, the wash solution line fluidly connecting the wash solution container and an inlet line of a blood component separation device; (b) connecting a red blood cell container to a red blood cell line, the red blood cell line fluidly connecting the red blood cell container and the inlet line of the blood component separation device, the red blood cell container containing a volume of packed red blood cells; (c) transferring, at a first flow rate, packed red blood cells from the red blood cell container to the blood component separation device; (d) transferring, at the same time as step (c), wash solution from the wash solution container to the blood component separation device, the wash solution being transferred at a second flow rate that is greater than the first flow rate, the wash solution mixing with the packed red blood cells in the inlet line, thereby diluting and washing the packed red blood cells, the blood component separation device separating washed red blood cells from the wash solution and a supernatant; (e) monitoring a volume of washed red blood cells collected within the blood component separation device; (f) drawing washed red blood cells from the blood component separation device and into a red blood cell product container when a target volume of red blood cells is collected within the blood component separation device; (g) monitoring a volume of packed red blood cells remaining within the red blood cell container; and (h) stopping, when the red blood cell container is empty, the transfer of packed red blood cells and reducing the transfer of wash solution from the second flow rate to a third flow rate. (a) connecting a wash solution container to a wash solution line, the wash solution line fluidly connecting the wash solution container and an inlet line of a blood component separation device; (b) connecting a red blood cell container to a red blood cell line, the red blood cell line fluidly connecting the red blood cell container and the inlet line of the blood component separation device, the red blood cell container containing a volume of packed red blood cells; (c) transferring, at a first flow rate, packed red blood cells from the red blood cell container to the blood component separation device; (d) transferring, at the same time as step (c), wash solution from the wash solution container to the blood component separation device, the wash solution being transferred at a second flow rate that is greater than the first flow rate, the wash solution mixing with the packed red blood cells in the inlet line, thereby diluting and washing the packed red blood cells, the blood component separation device separating washed red blood cells from the wash solution and a supernatant; (e) monitoring a volume of washed red blood cells collected within the blood component separation device; (f) drawing washed red blood cells from the blood component separation device and into a red blood cell product container when a target volume of red blood cells is collected within the blood component separation device; (g) monitoring a volume of packed red blood cells remaining within the red blood cell container; and (h) stopping, when the red blood cell container is empty, the transfer of packed red blood cells and reducing the transfer of wash solution from the second flow rate to a third flow rate.