To start your ginger bug, combine 1 cup filtered water, 2 tablespoons grated unpeeled fresh ginger, and 2 tablespoons granulated sugar in a clean glass jar. Stir well.

Cover the jar loosely with a cloth or coffee filter secured with a rubber band, and let it sit at room temperature (ideally 68-75°F / 20-24°C).

For the next 5-7 days, "feed" your ginger bug daily by adding 1 tablespoon of grated fresh ginger and 1 tablespoon of granulated sugar. Stir gently after each feeding.

Your ginger bug is active when it's consistently fizzy with visible small bubbles, especially after feeding. It should also have a pleasant, slightly yeasty aroma.

Once your bug is active, prepare your soda base: In a separate large bottle or jar, dissolve 1/4 cup granulated sugar in 4 cups filtered water. You can add 1/2 teaspoon grated fresh ginger for a stronger ginger flavor if desired.

Strain 1/2 cup of active ginger bug liquid into the soda base. Make sure to reserve the ginger solids from your bug in its original jar; continue feeding them weekly (or store in the fridge and feed monthly) to keep your starter alive.

Pour the combined soda mixture into clean, sealable bottles, leaving about one inch of headspace to allow for carbonation.

Allow the bottles to ferment at room temperature for 1-3 days. During this secondary fermentation, "burp" the bottles daily by briefly opening and re-sealing them to release built-up CO2 and prevent excessive pressure.

Once your desired level of fizziness is achieved, transfer the bottled sodas to the refrigerator. Chilling will significantly slow down the fermentation process. Enjoy your homemade fermented sodas chilled!