Mix the yoghurt and milk (at room temperature) in the 1 litre plastic container.
Fill the EasiYo flask up to the line with boiling water and place the container of milk inside.
Put the lid on and incubate at least 12 hours at room temperature.
Place yoghurt in the fridge for at least 1-2 hours. You may notice some liquid separating from the culture-you can either pour this off or mix it back in, as it is nutritious.