Cut the soap base into 1 inch cubes and add to the microwaveable safe jug.
Heat in the microwave on high for 30 seconds.
Remove and stir well with the craft stick. Heat in 10 second intervals, stirring well between each heating session, until the soap base is fully melted.
Set aside and allow to cool down for two minutes, then stir.
Add the majority of green tea, leaving some aside for the top of the soap bars, and the essential oil (if using), and stir well slowly until you can feel it cool down and get slightly thicker.
Pour into the soap mould. Use the craft stick to continue slowly stirring the soap in the mould until it starts to harden. It will look chunky on the top. This is what gives the soap a distinct look.
Sprinkle the remaining green tea on top.
Allow the soap to fully set for at least six hours, or overnight.
Remove from the mould and cut into four x 1 inch bars.