A "ginger bug" is a starter culture that will turn any fruit juice or sweetened herbal tea into a lightly fermented, naturally bubbly beverage. All you need in order to make one is fresh ginger, filtered or non-chlorinated water, and sugar.
Don't be alarmed by the inclusion of sugar in the ingredients. The sugar is food for the beneficial probiotic bacteria that you need in order to make your naturally carbonated soda. The longer you let your soda ferment, the less sugar is present in the final drink: You decide how sweet you want it to be according to how long you let the probiotics work on the sugars. But they do need some sugar in order to do their thing.
The reason for using filtered or non-chlorinated water (most municipal tap water is chlorinated) is that the chlorine can kill the beneficial bacteria you are trying to encourage.
Making a Ginger Bug
- 1 cup filtered or non-chlorinated water
- 1 tablespoon grated or finely chopped fresh ginger
- 1 tablespoon sugar
You'll get a more vigorous fermentation started quickly if you use organically grown fresh ginger and don't peel it. If conventionally grown ginger is all you can find, do peel it first.
Combine the ingredients in a glass jar and stir to dissolve the sugar. Cover the top of the jar with cheesecloth or a dishtowel. Leave it out at room temperature.
Every day for 3 days add:
- 1 teaspoon grated or finely chopped fresh ginger
- 1 teaspoon sugar
Stir vigorously each time to dissolve the sugar.
After the three days you should start to see some bubbles on the surface of the liquid. Screw on the jar's lid and transfer the ginger bug to the refrigerator. The cool temperatures of the refrigerator will slow fermentation, but not kill off the beneficial bacteria that are causing it.
Keeping Your Bug Going
Once you have a ginger bug started, you can keep it going in the refrigerator indefinitely by occasionally feeding it a teaspoon each of grated ginger and sugar.
How to Use Your Ginger Bug
- 1/4 cup active ginger bug
- 1 quart fruit juice or lightly sweetened, room temperature herbal tea
Strain the ginger bug into a quart jar. Add the juice or lightly sweetened tea and stir vigorously. Cover the jar with a clean cloth or towel and leave out at room temperature for 3 days. Stir the mixture vigorously at least twice daily (more frequently would be even better). Do not add any additional ingredients during this time.
By the end of the 3 days, you should start to see bubbles on the surface of the liquid. Taste a sip. If it is too sweet for you, leave the mixture out to ferment for another day or two.
When you are pleased with the degree of sweetness, transfer the soda to a thick flip-top glass bottle (such as those used to contain bubbly drinks like beer and soda). Or repurpose a plastic soda bottle for this use.
Secure the cap. Although during the initial fermentation you wanted the liquid exposed to air to allow gases to escape, now you want those gases to build up and create the effervescence you're after.
Leave the freshly bottled soda at room temperature for 24 hours, then transfer it to the refrigerator to chill before serving.
If you are using herbal tea rather than fruit juice, it is important to add sugar or another caloric sweetener. Remember that the sugar is for the probiotic bacteria, not you!
Keep a close eye on your naturally fermented soda once it is bottled and capped. If left out longer than 24 hours, or if the room temperature is very hot or the ginger bug super active, too much pressure could build up from the trapped gasses. That could result in a messy explosion! Transfer the soda to the cool temperatures of the refrigerator as soon as it is sufficiently bubbly.