Sugar gets a bad reputation — but in the world of fermentation, it plays a very different role. When you’re brewing kombucha, fermenting kefir, or experimenting with homemade sodas, sugar isn’t there just for sweetness. It’s the fuel that feeds beneficial cultures, supports healthy fermentation, and helps you get consistent results.
In this guide, we’ll break down what sugar actually does during fermentation, which sugars work best, and how to make smarter choices depending on what you’re brewing.
Why sugar is essential in fermentation
When you add sugar to a fermentation process, you’re not simply sweetening the drink. You’re feeding the microbes.
In kombucha, for example, the SCOBY (a symbiotic culture of bacteria and yeast) consumes sugar and converts it into:
- organic acids (which give kombucha its tang)
- carbon dioxide (for fizz)
- trace amounts of alcohol (usually very low in home brews)
- helpful compounds created during fermentation
The key point: most of the sugar is consumed during fermentation, especially if you allow the brew to fully mature. The end drink tastes less sweet because the microbes have been doing their job.
What types of sugar are used for fermentation?
Not all sugars behave the same way. Some ferment cleanly and predictably, while others can stress the culture or create off flavours.
1) White granulated sugar (cane or beet)
This is the “standard” for kombucha and many ferments because:
- it’s highly fermentable
- it’s consistent batch to batch
- it doesn’t add strong flavours that can mask fermentation signals
If you’re new to fermentation and want predictable results, plain white sugar is often the easiest starting point.
2) Organic cane sugar
Organic cane sugar is popular with home brewers who prefer:
- minimal processing
- a slightly more natural profile
- reliable fermentation like standard white sugar
It can be a great middle ground: still clean and consistent, but with the reassurance of organic sourcing.
3) Demerara, turbinado, and “golden” sugars
These sugars contain more molasses content than white sugar, which can:
- add a richer flavour
- slightly darken the brew
- sometimes speed or alter fermentation due to extra minerals
They can be brilliant for certain flavour profiles — but if you’re troubleshooting a brew, it’s usually better to simplify and return to white or cane sugar to isolate variables.
4) Brown sugar
Brown sugar is essentially white sugar plus extra molasses. It can be used, but it tends to:
- add stronger caramel notes
- create a heavier flavour
- be less consistent depending on brand and moisture content
Some brewers love it for spiced winter kombucha or ginger-based ferments, but it’s not always ideal for a clean “classic” kombucha base.
5) Honey (for Jun tea, not standard kombucha)
Honey ferments differently. It’s used in Jun, a similar fermented tea drink that uses honey rather than sugar. Honey has antimicrobial properties, so it can behave unpredictably in a standard kombucha brew unless you’re using a culture adapted for it.
6) Maple syrup, coconut sugar, and other alternatives
These can work, but they often introduce:
- extra minerals
- stronger flavours
- different fermentation speed and acidity patterns
They’re best used once you’ve got your brewing process consistent and you’re confident in how your culture behaves.
Does the type of sugar change the taste?
Yes — but usually in subtle ways.
- White sugar gives the cleanest, lightest base
- Cane sugar is still clean, sometimes slightly rounder
- Demerara/golden/brown adds depth and a more “toffee” tone
- Alternative sugars can create distinctive flavour notes (sometimes great, sometimes odd)
If you’re flavouring your kombucha with fruit, ginger, or herbs, the base sugar choice can either support those flavours or compete with them.
How much sugar should you use?
For kombucha, most recipes fall into a standard range that keeps the culture well-fed without overdoing it.
A common baseline is:
- about 70–80g of sugar per litre of sweet tea (varies by recipe and taste)
But what matters most is consistency. Changing sugar quantity dramatically can lead to:
- sluggish fermentation
- overly acidic brew
- yeast overgrowth
- weak carbonation
If you’re experimenting, change one thing at a time — it’ll save you wasted batches.
Common sugar mistakes that affect fermentation
Here are a few issues that regularly cause “my kombucha isn’t right” problems:
Using too little sugar
Your culture may struggle and the fermentation can stall, leaving you with flat, underdeveloped flavour.
Using strongly flavoured sugars too early
If you’re new to brewing, rich sugars can hide what’s happening. Start simple, then explore once you know what “normal” looks like.
Switching sugar types every batch
Fermentation is biological — microbes adapt. If you constantly change the fuel source, you’ll get inconsistent results.
Adding artificial sweeteners
Most artificial sweeteners do not feed fermentation cultures. They can also contain additives that aren’t friendly to SCOBY health.
Choosing the right sugar for your brew
Here’s a quick “cheat sheet”:
- New brewer or troubleshooting: white sugar or organic cane sugar
- Classic kombucha base: white sugar or cane sugar
- Richer, deeper flavour profile: demerara or golden sugar
- Jun tea: honey (with a Jun culture)
- Experimental brews: maple/coconut sugar once you’re confident
If you’re aiming for reliable results, the best sugar is usually the one that is consistent, dissolves easily, and doesn’t introduce too many variables.
Stocking up for your next brew
If you’re brewing regularly, it’s handy to keep a steady supply of fermentation-friendly sugars on hand so you can stay consistent from batch to batch.
You can browse a range of brewing sugars here:
https://happykombucha.co.uk/collections/sugars