Chop the ginger into large pieces and place into the Thermomix bowl. Mill 4 sec/speed 5. Store in an airtight container in the fridge and use as directed.
To begin the bug, place the full amount of water into a sterilised jar with 1 tbsp each of raw sugar and milled ginger. Give it a good stir, cover loosely with a paper towel or kitchen cloth and place into the pantry or a dark cupboard, overnight for up to 36 hours.
Each day for the next 5 days, feed the bug 1 tbsp each of the milled ginger and sugar and stir to combine. Cover and return to your dark resting place.
Once it is starting to release bubbles when you stir it, it is ready to use. If you are not organised to use it at this point, place it into the fridge and leave it there until you are good to use it in a drink recipe.
Before using it in recipe of choice, take it out of the fridge, allow it to return to room temperature, feed it as per above, and then use it after 6-12 hours in the cupboard!
To keep the bug active and healthy, top up the water, feed it again with sugar and a slice or two of ginger and keep in the fridge until the next use. Repeat step 5 after every use.