Sourdough Soda (Fermented Cinnamon & Raisin Drink)
A refreshing, lightly sparkling kvass-style drink made from toasted stale sourdough, cinnamon, and raisins.
Low sugar, gut-supportive, hydrating — and completely natural.
🥤 Ingredients (1.5–2 L)
- 200–250 g stale sourdough bread (ideally wholegrain or rye-based)
- 1.5 L water
- 50–70 g sugar or honey (fuel for fermentation; most is consumed)
- 1 small handful raisins (10–15)
- 1 cinnamon stick (or ½ tsp ground cinnamon)
- Optional but helpful: 1 tbsp active sourdough starter
- Optional flavour extras:
- strip of lemon peel
- a few cloves
- thin slice of fresh ginger
🍞 Method
-
Toast the bread
Cut the stale sourdough into chunks and toast at 180 °C until deep golden-brown with some darker edges.
This builds flavour, colour, and melanoidin/antioxidant complexity. -
Make the infusion
Add the toasted bread, raisins, cinnamon (and any optional peel/spices) to a large pot.
Pour over 1.5 L of water.
Bring just to a gentle simmer for 5–10 minutes, then switch off the heat. -
Steep and cool
Let the mixture steep as it cools to room temperature (about 1–2 hours).
You’re making a flavoured, bread-based “tea” as the base of the soda. -
Strain
Pour through a fine sieve or cheesecloth into a fermentation jug or large jar.
Gently press the bread to extract liquid, but don’t mash it into paste. -
Sweeten and inoculate
Once the liquid is just warm (not hot), stir in the 50–70 g sugar or honey until fully dissolved.
If using, add 1 tbsp sourdough starter and stir again. -
Primary fermentation (12–36 hours)
Cover the jar with a clean cloth or a loose lid.
Leave at room temperature for 12–36 hours.- At ~12 h: very mild tang, little fizz
- At ~24 h: more flavour, light carbonation
- At ~36+ h: tangier, more pronounced fermentation
Taste every 8–12 h and stop when it reaches a pleasant balance of light sourness and gentle fizz.
-
Bottle and carbonate
Strain again if needed into clean swing-top bottles or screw-cap glass bottles.
Add 2–3 fresh raisins to each bottle (traditional kvass trick: they float when it’s ready).
Seal and leave at room temperature for 6–12 hours to build carbonation. -
Chill and serve
Move bottles to the fridge to slow fermentation.
Open carefully (over the sink the first time), pour into a glass, and enjoy chilled.
🌿 Notes & Variations
- Best consumed within 3–4 days for optimal flavour and low alcohol (typically well under 1% if timings are modest).
- For a more citrusy profile, add lemon peel and reduce cinnamon slightly.
- For a ginger version, add a thin slice of fresh ginger during the initial simmer, then remove before bottling.
- If you prefer it less sweet, ferment closer to the 36-hour mark so more sugar is consumed by the microbes.
🔍 BRAIN Diet Snapshot
- Systems targeted: Gut–brain axis, hydration, mild SCFA support, emotional regulation (sensory / olfactory), circadian-friendly evening drink.
- UPF profile: 100% non-UPF; uses simple ingredients and fermentation rather than additives.
- Use case: As a low-sugar, low-alcohol alternative to soft drinks in the evening, or as a gentle digestive drink with meals.
🧠 Scientific Sidebar
Mechanistic Notes (Gut–Brain Axis, SCFAs, Neurochemistry)
1. Fermentation & the Gut–Brain Axis
- The drink captures lactic acid bacteria and wild yeasts originating from the sourdough bread.
- Fermentation generates organic acids (lactate, acetate) and a modest range of postbiotic molecules (small peptides, microbial metabolites).
- Even in low doses, these can help shape the gut environment and support vagal signalling and gut–brain communication.
2. SCFA Potential (Downstream)
- The drink itself is not a fibre source, but regular fermented-food intake is associated with:
- increased diversity of SCFA-producing microbes
- improved production of butyrate, acetate and propionate when the overall diet is fibre-rich.
- In the context of the BRAIN Diet, this drink is a supporting ferment alongside fibre-rich meals, not a stand-alone SCFA source.
3. Mineral & B-Vitamin Availability
- Prolonged soaking and simmering of sourdough bread can solubilise:
- magnesium
- potassium
- trace zinc
- a fraction of B-vitamins (notably B1, B3, B6; heat-sensitive losses partly offset by prior sourdough fermentation).
- Sourdough fermentation itself reduces phytates, which can enhance mineral bioavailability in the crumbs used.
4. Polyphenols, Melanoidins & Antioxidant Effects
- Toasting the bread to a deep golden-brown creates melanoidins and transforms existing polyphenols.
- These Maillard-derived compounds may act as mild antioxidants and prebiotics, supporting beneficial gut bacteria and lowering oxidative stress.
5. Glycaemic and HPA Axis Considerations
- Most of the added sugar is consumed by microbes during fermentation, reducing the final glycaemic load.
- Compared to sweet soft drinks, sourdough soda is much less likely to cause rapid glucose spikes and downstream cortisol / adrenaline surges, offering a calmer metabolic profile that aligns with ADHD and mood-stability goals.
6. Sensory & Emotional Regulation
- The combination of gentle carbonation, cinnamon aroma, mild acidity and ritual (toasting, brewing, bottling) offers:
- sensory richness without ultra-processed hyper-stimulation
- a calming, predictable evening drink pattern
- potential support for emotional regulation via olfactory–limbic pathways and reduced reliance on sugary or alcoholic drinks.