Pour drinkable warm water into a sealable container

Add sugar and stir to dissolve

Add powder milk and stir until dissolved, you can sieve it if not smooth

Add store bought yoghurt and stir (starter yoghurt)

Close the container and seal with a foil before covering it with kitchen towel

Keep in a warm place for 12 to 14 hours (keep longer for a thicker yoghurt)

After 14 hours, refrigerate until chilled before serving