Every week when I brew kombucha I have a ton of yucky yeasties in the bottom of each of my vessels – and while I know it’s actually good bacteria working hard, it’s very cloudy and stringy.
It’s actually not all that yucky though, it looks worse than it is. But every week I hated to throw it out, and I really didn’t want to carry the sludge to the next week. In the past, we have used milk kefir to make sourdough bread, and it worked relatively easy – there has to be a way to use kombucha to make sourdough too. Right?!
Sludge makes the Perfect Sourdough Starter
Next time you find yourself cleaning the sludge from the bottom of your kombucha vessel, keep that liquid – it’s full of yeasties that is perfect for making bread.
The cloudier your sludge from the bottom of the kombucha vessel, the better – just set it aside and you’ll find that this is a wonderful way to make your next loaf – as an added bonus, making starter from this cloudy kombucha is actually much easier and faster than making traditional sourdough starter that you would have to feed daily for almost a week.
What is Kombucha?
Kombucha is a symbiotic culture of bacteria and yeast (or, as we most commonly know it as SCOBY). The yeasts (which some are used in baking and brewing) ferment the sugar into alcohol in which the bacteria are converted into acetic and gluconic acid.
We use our SCOBY most commonly to make kombucha – which is a sweet tea that has been fermented, and has a wide range of health benefits. My kids have dubbed the SCOBY their “scary alien” but it’s really not all that scary at all – it’s more gross looking than anything, but keep in mind that the probiotics in the SCOBY help foster healthy bacteria in your stomach lining and digestive tracts.
Kombucha Sourdough Starter
Making this kombucha sourdough starter is relatively easy – you’ll want to mix the ingredients for the sourdough starter the night before you want to make the bread. Set aside 1 1/2 C. of the cloudy, yeasty kombucha bits from the bottom of the vessel, and combine with 1 1/2 C. of flour in a large jar or bowl. Stir well with a non-reactive spoon, and cover loosely with a cheesecloth or coffee filter.
For the flour, use your favorite variety – organic unbleached all purpose, or rye, a mix of spelt and rye, or even a gluten-free variety.
Leave sit in a warm place – the oven is a wonderful place for this, make sure you shut the oven door and turn off the light. In the morning, the mixture should be nice and bubbly, and some of the liquid may have begun to separate from the flour. There should be enough yeast now to make your bread.
Give it a good stir and redistribute the separated liquid and use that starter to make sourdough bread.
When is the starter ready?
Bubbles on the surface don’t always indicate that the starter is ready – because once you feed the starter, it can bubble just from the activity of you adding and stirring. I have found that the best way to check my starter before making bread is to fill a cup with water at room temp – then add a spoon or so of the starter to the glass. If the starter floats, it’s active and ready. If it sinks.. then feed again and allow to sit 4-5 hours before checking again.
If your starter is not ready, you may have to feed your starter again and wait an additional day – to feed again, give it equal parts of kombucha sludge and flour, and give it a good stir with a non-reactive spoon.
A strong, healthy starter with lots of bubbles will make a wonderful fluffy bread, so if you don’t feel as if it’s ready yet, give it a few days of feeding and wait patiently until you see active bubbles on the top of your starter, or do the water test.