(Yield : one-half gallon)
2 quarts water
2-inch piece fresh ginger root (or more), minced
1⁄2 cup fresh lemon or lime juice
Bring 2 quarts of water to a boil. Add ginger root, sugar and salt. Stir to dissolve. Lower heat and simmer for 30 minutes. Remove from heat and let cool to room temperature. Pour through a strainer lined with muslin cloth into a large crock or glass jar. Stir in the ginger bug or whey and the lemon or lime juice.
Cover container with muslin cloth and secure cloth with a rubber band. Ferment at room temperature for 24 hours. Transfer into four 16-oz bottles using a funnel and a strainer. Be sure to use bottles made to withstand pressure. Leave an inch of head space in each bottle.
Allow the ginger beer to ferment in bottles for 2-7 days at room temperature, checking for carbonation daily. Once carbonated, transfer to the refrigerator for an additional two days to age. Consume within 4 weeks.
Cold storage slows down fermentation activity, but does not stop it. Always open bottles carefully over a sink.
Recipe adapted from Wild Fermentation.