Sourdough Cold Brew Coffee Soda
A lightly fermented, naturally fizzy coffee soda using sourdough culture for gentle tang, sparkle and gut-loving benefits.
I have become a little addicted to this. I made it early on in the development of the course and it is still going strong!
This sits right at the crossroads of caffeine and culture. Cold brew coffee is lightly fermented with sourdough starter to create a softly fizzy, subtly tangy soda that feels refreshing rather than heavy. It’s coffee, but calmer, less acidic, gently sparkling and designed to be sipped, not slammed. As part of the Gut Instinct drinks chapter, this is a clever way to use sourdough discard while introducing fermentation into your daily coffee ritual. Perfect over ice on warm days, or topped up with sparkling water for a long, slow afternoon drink.
We completely riffed in the video attached, and it was fantastic, so go for it, what will be your favourite combo?
I did say I would link the Brewspresso Fizz Tonic recipe here. This is using Brew Choc, which alas, is no more unless you have some in the back of your pantry. Coffee is a great substitute, though completely different flavour of course.
Serving suggestions & additions
Serve over plenty of ice with a twist of orange or lemon peel to lift the natural coffee bitterness.
Top with sparkling mineral water for a lighter, long-drink style soda.
Add a splash of vanilla syrup or vanilla bean paste for a soft, cream-soda vibe without dairy.
Sweeten gently with a little honey, maple syrup or date syrup if you prefer a rounder finish.
Serve with a dash of cinnamon or cardamom for warmth and spice.
Pour over ice and finish with a thin slice of fresh ginger for extra zing and digestion support.
Use as a mixer with tonic water for a coffee-tonic style drink.
Add a float of cold foam, oat milk or coconut cream for a creamy-top contrast.
Serve in a wine glass with ice and citrus for an aperitivo-style coffee soda moment.
Dilute with chilled herbal tea (like chamomile or rooibos) for a softer caffeine hit.
Need
- 150 Grams coffee beans of your choice
- 2 Litres filtered water
- 10 raisins, plus some more
- 2 Teaspoons Sourdough Starter Recipe
- 1 Tablespoon raw sugar per day for 5 days
Do
- 1
You will need a large jar with a lid that will fit about 2.2L of liquid or more for this recipe.
- 2
Place coffee into the Thermomix bowl and mill 20 sec/speed 8. Your coffee shouldn't be super fine, so the time may depend slightly on your coffee beans. Tip into the large jar.
- 3
Add the water to jar and give it a good stir with a spatula. Seal the jar and leave on the bench at ambient room temperature for 24 hours minimum, an extra day is also ok.
- 4
Strain the coffee well, I use a nut milk bag for best results. Return the liquid to the cleaned jar. (Use the solids as garden mulch, my herb garden has never been so fine!)
- 5
Add the raisins, sourdough starter, and 1 tbsp of the sugar to the jar and stir to combine. Seal the jar and leave on the bench for 5 days, opening and adding an additional tbsp of sugar every day.
- 6
When you open the jar by the 5th day you should be getting a slight fizz and also there should be bubbles rising in the liquid when you open the jar.
- 7
Strain and divide between 1 litre glass bottles with a pop top lid (available at Kmart for way less than a kitchen store) and you can further ferment another 1-2 days on the bench. A great way to know that you are getting good fermentation is by using the raisins. Once they float to the surface, you can assume you have good fizziness. You should burp the bottles a couple of times a day so as to avoid the possibility of a kitchen explosion.
- 8
Try this on its own or use in our drink suggestions. It is really a great way to get your coffee fix without dairy if that is your thing.
This recipe can be seen if you sign up for the related course. Join the course to get access!
Gut Instinct Protocol: The Power of Fermented and Cultured Foods
Tenina Holder is a wife, mother of five and grandmother of nine, who started cooking in the olden days before Thermomix was even a thing.
Tenina has become the premium go to source for all Thermomix expertise and of course fresh and easy recipes that work. Her cooking classes and foodie trips are sold out in literally hours, her cookbooks appear on the Australian best seller lists and her social reach is in the millions. Her Insider Club is the most fun you can have with a Thermomix and you really should join her! She believes chocolate, butter and salt are health foods. Her food positivity mantra is, eat everything, just not all at once!
