My notes are in the parenthesis. Makes about 8 cups (enough to fill a 2-liter plastic soda bottle)
The original story and recipe I used is found on The Kitchn.com and is by Emma Christensen and here’s her The Bold Brewer

INGREDIENTS

  • 2-inch piece fresh gingerroot (3 tablespoons)
  • 1 cup water, plus more to fill the bottles
  • 9 tablespoons/4 ounces white granulated sugar, plus more if needed (Sugar in the Raw, Turbino cane sugar) (1/2 cup + 1 tablespoon)
  • 1/8 teaspoon salt
  • 5 tablespoons freshly squeezed lemon juice (from 2 to 3 lemons), plus more if needed (1/3 cup = 5 tablespoons)
  • 1/8 teaspoon dry champagne yeast (added about a 1/16 more)

INSTRUCTIONS

  • Peel and finely grate the ginger (I use a Microplane). You should have about 2 tablespoons of grated gingerroot.
  • Bring the water to a boil in a small saucepan on the stove top or in the microwave. Remove from the heat. Add the sugar and salt and stir to dissolve. Add the ginger and let stand until cool. Stir in the lemon juice.
  • Pour the ginger water into a clean 2-liter bottle using a funnel. Do not strain out the ginger. Top off the bottle with water, leaving at least 1 inch of headspace. Give it a taste and add more lemon juice or sugar if desired. The extra sugar will dissolve on its own.
  • Add the yeast. Screw on the cap and shake the bottle to dissolve and distribute the yeast. Let the bottle sit at room temperature out of direct sunlight until carbonated, typically 12 to 48 hours, depending on the temperature of the room. Check the bottle periodically; when it feels rock solid with very little give, it’s ready.
  • Refrigerate overnight or for up to 2 weeks. Open very slowly over a sink to release the pressure gradually and avoid bubble-ups. Pour the soda through a small fine-mesh strainer to catch the ginger as you pour.
Ginger ale bottles

RECIPE NOTES

  • Bottling in Glass Bottles: Sodas can also be bottled in glass or swing-top bottles, but it’s more difficult to tell when the sodas have fully carbonated. Therefore, with every batch you bottle, also fill one small plastic soda bottle to use as an indicator for when the sodas have finished carbonating. Refrigerate all of the bottles as soon as the plastic bottle is carbonated; never leave the glass bottles at room temperature once carbonated.
  • Sugar-Free Soda: Use 1 tablespoon of white granulated sugar per 8 cups of soda to carbonate, but beyond that, you can sweeten to taste with another sweetener of your choosing. The sugar will be almost entirely consumed during fermentation.
  • Alcohol in Homebrewed Sodas: As long as yeast is being used to carbonate beverages, alcohol will be made as a by-product. However, the short fermentation time limits the amount of alcohol produced in sodas, and it typically comes out to less than 1 percent.
  • How to Avoid Gushing, Exploding, Overcarbonated Sodas: Sodas can overcarbonate very easily. This can cause geysers when you first open them or bursting bottles if left unrefrigerated for too long. Refrigeration suspends fermentation (and therefore carbonation), but it will start again when the bottles are removed from refrigeration.
  • It’s best to bottle sodas in used (cleaned!) plastic soda bottles since it’s easy to gauge carbonation just by pressing the side. Always open sodas over a sink or outside, and unscrew the cap extremely slowly to allow pressure to release gradually.