Rhubarb season is one of our favourite times of the year. Last year we were all about rhubarb kimchi, if this sounds up your street then checkout the recipe. We're always on the lookout for new ways to make use of this unique veggie (yes, rhubarb is a veg!) and this year we thought we'd try out a fizzy, living rhubarb soda made with our ginger bug as a starter.
The process basically takes homemade rhubarb cordial, tops it up with water to make a delightful drink and then adds a starter (a predefined ecosystem of microbes which carry out fermentation for us) which ferments some of the sugars creating carbon dioxide (and small amounts of alcohol) as a by-product!
In the case of the ginger bug we're using to kickstart fermentation it will mostly be yeasts and bacteria (some of which will be lactic acid bacteria, like those found in sauerkraut and kimchi). These microbes make the drink less sugary and create the fizzy drink we're after. Commercial fizzy drinks are carbonated by 'force-carbonation' which means they introduce carbon dioxide under pressure to create the bubbles. With naturally fermented sodas it's microbial power alone that makes those all-important bubbles!
This living rhubarb soda turned out SO well and we'd love you to give it a go. You'll need a ginger bug to make it, or another source of starter liquid. You could use a starter made with other yeasty ingredients, some finished kombucha, water kefir or whey. All of these will provide the microbes to ferment those sugars and get those bubbles going.
Ingredients (makes around 1 litre)
Rhubarb x 450g
White sugar x 100g
Water x 750ml (plus extra)
Ginger bug starter liquid x 30ml (see previous recipe on making wild bugs)
Method
Put the rhubarb and sugar in a medium saucepan, add 750ml water and stir to combine.
Bring to a boil, and then reduce the heat and simmer gently for about 8 minutes. The rhubarb will have given up its color and flavour and will be very soft.
Let the mixture cool to room temperature, then strain through a fine sieve or cheesecloth. Push gently to get as much of the juice out as you can. This is your rhubarb cordial. We recommend using the solid part to mix with yoghurt in baking or in a rhubarb fool.
Refrigerate the rhubarb cordial until you're ready to make soda or you can just mix with water and drink as it is right now!
Mix the rhubarb cordial with equal parts water in a bottle that can fit 1-1.5 litres (we use an empty plastic soda bottle).
Sieve out 30ml starter liquid from your ginger bug (or other wild bug) into a measuring jug (you can use weighing scales to measure 30g) and pour into the rhubarb mix.
Seal the bottle and gently invert to combine then leave at room temperature for 1-3 days until fizzy. If you're using plastic then you'll be able to feel the bottle get firmer as gases build up. If you're using glass then make sure to keep burping the bottle so that pressure doesn't build up. You don't want exploding bottles on your hands!
8. Once it tastes as you'd like and it's fizzy pop in the fridge and enjoy within one week. It will last longer than this but is likely to keep getting more sour and therefore less enjoyable.