A ginger bug is a natural soda starter: a fermented slurry of ginger, sugar, and water that contains beneficial bacteria. Once started, you use the ginger bug to make naturally fermented sodas, such as ginger beer, or using any type of fruit juice or herbal tea with sugar as a base.
Just like making kombucha, making a ginger bug involves sugar for the bacteria and yeast to consume, and time for the fermentation to happen.
Choosing Ginger and Sugar to Use
If you're using organic ginger you won't need to peel it for this recipe. But since organic ginger can be a little expensive, it's OK to use conventional ginger as long as you peel it (the peel is where most pesticide residue would be found). You can use a standard vegetable peeler or a sharp paring knife to peel ginger knobs.
It doesn't matter what kind of sugar you use as long as you don't use honey. It won't ferment properly. Some purists insist on using natural, unrefined sugar or evaporated cane juice, but white table sugar works fine.
Here's what you'll need to start your ginger bug:
Quart mason jar
Sugar of your choice
2 cups dechlorinated or filtered water
Tightly woven cloth and rubber band to cover
2 to 3 tablespoons grated or chopped organic ginger
Pour the water into your quart jar. Finely chop or grate your ginger, and measure out 2 to 3 tablespoons.
Add the ginger to the water, then measure out 2 to 3 tablespoons sugar, and add to the jar. Whisk or cover and shake until thoroughly blended.
Each day, add 2 more tablespoons ginger and 2 more tablespoons sugar and whisk or stir well with a wooden or plastic (not metal) spoon. Or, add just one teaspoon of each, until the mixture is very bubbly (it should bubble before you add new sugar and ginger).
If you prefer a slower starter, or you want to have it be less time-intensive between batches, you can store the ginger bug in the refrigerator and add at least 1 tablespoon each of ginger and sugar every week.
If mold grows at the top of the jar, you can scrape it off, provided it's just a small amount. If you have more than one instance of mold, however, you'll have to scrap the batch and start fresh, unfortunately.
How to Tell When Your Ginger Bug is Ready
When the ginger bug is bubbling away vigorously, it's ready to use. This can take as little as three days to a week or more, depending on the temperature of the room. You will use 1/4 cup of strained starter to every quart of "soda" liquid that you use. Make sure if you use tea that it has cooled to barely warm, as heat will destroy the good bacteria and yeasts in your starter.
After you've removed your liquid, replace the water in your starter jar and add more sugar and ginger, and wait a couple of days before using your starter again.
Making Lacto-Fermented Soda
Pour 1/4 cup of ginger bug through a strainer into a measuring cup.
Make your soda base: fruit juice, sweetened tea, ginger boiled in water with sugar or whatever you want.
Remember that fermentation will make your soda more acidic than it tasted before, so you may have to compensate by adding extra sugar. And flavors that blend well with ginger are key.
Add the ginger bug starter to the tea base and stir well. Cover with a cloth and rubber band. Two or three times a day, stir the liquid well.
Storing Your Ginger Concoction
After three days, pour your soda into sealed bottles. This will make your soda fizzy, similar to secondary fermenting kombucha. Glass beer bottles or a mason jar with a sealed lid will work, as will plastic soda bottles. In fact using a plastic soda bottle can help you tell when the ferment is ready, as the bottle will be hard to the touch just like store bought soda.
If you use glass, be careful to check it and "burp" the bottles every 24 hours (release some of the gas) so they don't explode.
And make sure you open them in the sink, or outdoors.
After 24 hours or when fully carbonated, move your natural soda to the refrigerator, and enjoy. Use it within a few weeks so it doesn't get too flat.