In order to pour the perfect amount of tea to fill a standard cup (as seen in the image), release the tea-pouring cord the instant you see water pouring out of the glass spiral.

Try keeping an eye for when the entire spiral is filled with liquid, then letting go of the cord a tiny bit after. The result should be a perfectly poured cup of tea, with Boro complementing on your tremendous success!

Refer to the included image as a rough guideline, I let go the cord as soon as I saw liquid pour out of the spiral.



Reminder: This is not a requirement for customer satisfaction, nor is an achievement that I know of bound to this specific task.