Boil the water.
Make up the tea in a jug or large jar
Allow to steep until it becomes room temperature.
Strain into a large jar, leaving room at the the top.
Add the 1/2 cup of kombucha and SCOBY.
Cover with a folded tea towel and secure with an elastic band.
Store away from direct sunlight for a week or until brewed to your taste.
Once the brew is to your taste, carefully pour / strain into a bottle, leaving about half a cup of kombucha and the SCOBY to use for the next batch.