Add the grated ginger, 2 tbsp sugar and the water into a lidded jar, and mix with an wooden spoon to combine.

Loosely lid the jar and keep it at room temperature.

Every day, for the next 4-5 days, feed the mix with 1 tbsp sugar and 1 tsp grated ginger, and use the wooden spoon to give it a stir.

In the 4th or 5th day, the cultured mix should be ready and bubbly on top. It may turn opaque, this is ok. It might develop a white mold layer, this is ok too - you simply remove it before using. White mold is ok, pink or black mold means you should  start the fermentation process again. 

Use 1/2 cup of the mix for the ginger bug and keep the rest in the refrigerator (feed it once a week with sugar and ginger to keep it alive).

In a medium soup pot add 4 cups water,  grated ginger and sugar and bring to boil over medium heat.

Simmer for 5 minutes, then strain and let cool completely.

Transfer the mixture into a jar, add the rest of the water, lemon and ginger bug, mix with an wooden spoon and lid the jar tightly.

Let sit at room temperature for 2 &1/2 days, until fizzy.

Serve or keep in the refrigerator for up to one week.