Overstocked, and accumulated a stockpile of old coffee grounds at home? In our fifth episode of Coffee On, we collaborated with Singapore's 'Prince of Fermentation' Ding Jie Tan, founder of Starter Culture to discover creative ways to repurpose old coffee grounds.
If naturally fizzy coffee 'soda' is something you might like, then this recipe is for you!
Coffee Kombucha Recipe
Ingredients Makes 1litre 900ml water 100ml Kombucha starter 100g coarse-ground coffee 80g raw cane sugar/honey/white sugar
Equipment Glass jar (at least 1000ml) Paper filter Kitchen towel or clean cloth Rubber band
Step 1: Brew the coffee Steep coarse-ground coffee in 700 ml of water for 10 hours at room temperature. Strain with a paper filter to remove sediments and oils.
Step 2: Add Kombucha starter Dissolve 80 g raw cane sugar in 200 mL water. Combine and mix the sugar syrup, kombucha starter, and cold brew coffee in a large glass jar.
Step 3: Ferment for 5 to 7 days Cover with a clean kitchen towel and secure it with a rubber band. Leave it in room temperature. Label and monitor the fermentation process over 5 to 7 days. Reserve 100ml of your fermented coffee as a starter for your next batch of coffee konbucha!
Step 4: Bottle for 3 to 4 days Transfer to an air-tight bottle and top up with sugar (1g sugar of per 100ml of kombucha). Refrigerate when bubbles are observed at the surface. Once it's chilled, you can pour and enjoy your naturally fizzy and fruity coffee ‘soda’!
Observe the fermentation process by smelling and tasting small portions along the way.
When using old or spent coffee grounds, double the amount of coffee needed in the recipe.
Look for lighter roast coffee to allow the fruity characteristics to shine through.
A cellulose gel or pellicle forms on the surface of kombucha. This is a natural, edible by-product.