How to make naturally fermented ginger beer at home
Peel and grate a 1-inch nub of fresh ginger (about 1 tablespoon).
Add the grated ginger, 1 tablespoon of sugar, and two cups of filtered water or spring water
(non-chlorinated) to a jar and stir. Cover the jar with a cheesecloth or towel and secure it with a rubber band. Allow jar to sit in a dark place for 24 hours.
Once a day for 4 to 10 days, add one teaspoon of sugar and one teaspoon of grated fresh ginger to the jar and stir well. This ensures your ginger starter stays fed and grows, similar to sourdough starter. Stir a couple of times per day. During this process, natural yeasts are released and create a white substance at the bottom of the jar. This is where the probiotics come from.
After 3 to 5 days (longer if your house is very cold), the liquid will begin bubbling when you stir it. Once you can see and hear bubbles without touching the jar, your ginger bug is ready to be used. If after 7 days, your ginger bug is still not bubbling, continue adding a teaspoon of sugar and ginger until it does. Note that amount of time it takes to get a ginger bug active varies widely depending on the temperature of your home and the activity of the bacteria and yeast.
Use the liquid from ginger starter to make ginger beer (instructions below).
Fill a gallon-sized jug most of the way up with spring or well water (do not use water from the tap unless your house runs on a well). This water should be room temperature or slightly warmer (aim for 70 to 78 degrees).
Stir the ginger starter well. Add 1 cup of the ginger starter, sugar, lemon juice, grated ginger, and the ginger starter. Stir very well. Cover the jug with a cheesecloth or towel bound by a rubber band and put it in a dark place at room temperature for 8 to 10 days.
Taste-test the mixture periodically to see if more sugar needs to be added (the natural probiotics will eat the sugar so if the beverage ever loses all of its sweetness, add a little more sugar (no more than 2 tablespoons at a time).
Stir the mixture once or twice a day. You will notice a white substance forming around the ginger at the bottom of the jug. The ginger beer is ready when the substance becomes bubbly when stirred (similar to when you’re making the ginger starter).
Once the ginger beer is ready, give it a taste test. If it doesn’t taste sweet, add additional sugar and ginger - once you bottle the brew, it goes through secondary fermentation and the probiotics will need more sugar to survive.
At this point, your options are to either bottle the ginger beer as-is or flavor it prior to bottling it. If you choose to leave the ginger beer as-is, simply transfer the ginger beer to
glass bottles, secure the lids, and place bottles in the refrigerator.
If you choose to flavor the ginger beer, add your flavoring ingredients to the flip cap bottles (see blog post for flavor ideas and instructions for secondary fermentation) prior to filling the bottles up with ginger beer. Secure the lids on the bottles and leave at room temperature for another 2 days.
Place bottles in the refrigerator to calm the fermentation process. Note that the ginger beer will continue to ferment in the refrigerator, so try to consume the beverage within a few days after secondary fermentation is complete for best results. Leaving it in the refrigerator for longer than a week will result in a “drier”, less sweet ginger beer.
You can now brew another batch of ginger beer using the ginger starter you have been feeding. Because your ginger starter is now more mature, it will take a little less time to brew your second batch.