I replace the yeast used in the former with the latter, so that I get a wild starter.
I put in more sugar and ferment for several weeks, aiming for an alcohol content of around 5 % by volume. The detailed calculation is left as an exercise to the reader.
Ingredients for three 2 liter bottles
- ca. 800 ml ginger bug (half that should also be fine)
- 7 tbsp grated fresh ginger
- 1 l cane sugar (900 g?)
- Distribute the ingredients evenly on the three bottles (water helps) and fill up with cold water, leaving about 5 cm of headspace.
- Screw the caps on the bottles and do some inverting to aid the sugar in dissolving.
- Put the bottles in a not too cold place. After a day or two they should be quite hard. Carefully loosen the lid, so that gas comes out, but still maintain some pressure.
- Every few days, tighten the lid, invert the bottles and loosen the lid again.
- After some time (probably at least two weeks), screw the lid tight and let ferment until the bottles are quite hard. Put them in the fridge.
- Once they are properly cooled, the beer is ready for consumption. Be careful with opening.
- It might be a good idea to use bottles which contained something sparkling before. Others might not be built to withstand high pressure.
- In the winter months I found it quite useful to put the bottles on top of a radiator. – Cozy warmth speeds up the fermentation, but is by no means necessary. It would be a sin to turn on extra heating just to make this ginger beer.
- If during the final fermentation not enough pressure is generated, you might add a teaspoon of sugar to each bottle and ferment for some more days.
- When mixing the ginger-sugar-ginger bug mixture in the beginning, it might not be a good idea trying to dissolve all the sugar in the ginger bug. The osmotic pressure would kill the yeast.
- I can't give a good total fermentation time, because it is very dependent on the environment and the mode of letting out gas. A carboy with airlock would probably be fastest.
Notes on the last batch
- Started the last batch at 2014-02-28. Still fermenting.
- Ginger bug had nearly died because of too much sugar. Saved it by halving and filling up with water.
- Non-carbonated water bottles from Bilka are not so well-suited.