Which sugar is best for fermenting?
The use of sugar in brewing and fermenting can raise a lot of questions, particularly if you’re just getting started in this creative realm. We’ve put together a brief overview of why you need to add sugar for brewing your ginger beer and kombucha, what types of sugar are the best for your products and some suggestions for experimentation.
The use of sugar in brewing and fermenting can raise a lot of questions, particularly if you’re just getting started in this creative realm. Below we’ve put together a brief overview of why you need to add sugar for brewing your ginger beer and kombucha, what types of sugar are the best for your products and some suggestions for experimentation.
Why do I need to add sugar?
Without sugar, there is no kombucha or ginger beer! The ginger beer yeast and/or your kombucha SCOBY (Symbiotic Culture of Bacteria and Yeast) need to be fed with sugar to allow the fermentation/brewing process to happen.
Below is a graph to show how the yeast consumes the sugar that you are adding. Once you add your yeast or kombucha SCOBY to your sweetened brew the yeast begins to digest the sugar and produce ethanol and CO2 (carbon dioxide). The amount of ethanol that is produced is controlled by the amount of sugar that is added, as well as how much time it the yeast has to ferment.
With both ginger beer and kombucha there is a first and second ferment step.
Step 1: Most of the sugar used is added here and fermentation happens in a fermenting vessel/jar/crock so the CO2 that is produced can escape. If you lengthen this step you can go all the way to a very low sugar beverage, but it depends on taste preference.
Step 2: For the second ferment a measured amount of sugar is added to each bottle before adding your ginger beer or kombucha. This feeds the yeast up just enough that they produce CO2 bubbles to make your drink fizzy, but not so much that the bottle explodes.
With kombucha there is also the additional activity of the bacteria! The bacteria take the ethanol that is produced by the yeast and turn it into healthy acetic acids. This is why kombucha can be so good for your gut health, but beer is not.
How much sugar do I add?
The amount of sugar is specified in your recipe. If you are making non-alcoholic ginger beer you only complete Step 2 of the process so
For kombucha the sugar addition is very important as it ensures normal healthy development of your kombucha. If you add too much sugar the balance of yeast to bacteria will change and your kombucha will be overrun with yeast, giving too much alcohol and off flavours. If you don’t use enough sugar you will inhibit the SCOBY growth and production of acetic acid, this may also lead to increased mould issues due to an unhealthy SCOBY.
How much sugar will be left at the end of my first stage of fermenting?
The majority of the sugar is consumed by the yeast and is broken down into fructose and glucose, these both have a lower glycaemic impact on the body.
The longer you ferment, the more sugar that will be converted by the yeast so experiment with ferment times to get your preferred sweetness profile.
What type of sugar should I use for my ginger beer or kombucha?
For ginger beer we recommend brown sugar for Step 1 of your Alcoholic Ginger Beer fermentation. This gives a lovely caramelised note to your end ginger beer. For Step 2 we recommend white cane sugar as it’s readily available to produce the best carbonation.
Cane sugar or more commonly known as white sugar is the best and most common type of sugar used for kombucha brewing. It is the most easily available source of sucrose for the yeast to convert to ethanol.
If you want to try some different options, we have given you some info below. Any of the below options can be used for ginger beer, they will each give quite a different flavour to your final product.
Before getting stuck into sugar experimentation with your kombucha we recommend that you make sure you have completed a few good strong brews and have back up SCOBYs. SCOBYs can be temperamental at times and may not easily adjust to a new sugar for fermentation. The best way to experiment is to substitute a portion of your white sugar for your preferred sugar alternative and figure out what gives you your favourite flavour profile. We recommend starting with 1/4 new/alternative sugar source + 3/4 white sugar.
The possible options:
Evaporated Cane Juice or Cane Juice Crystals – this is a less refined sugar and is a good option to try.
Brown Sugar – this works well for ginger beer but is harder for the SCOBY to break down. It will contribute a more caramel/molasses flavour.
Coconut Palm Sugar or Syrup – this will work well but may give sour or bitter flavours due to the high level of minerals. It may need a shorter brewing time so keep regularly tasting your brew.
Agave or Maple Syrup – make sure it is a pure source and not mixed with anything. For kombucha this may require some experimentation and extra culture to be added at the start to give your SCOBY the best possible chance of survival. We recommend starting with proportions of white and new/alternative sugar to allow adjustment of your SCOBY.
Molasses – this has a relatively low level of sucrose so is best paired with a mixture of white sugar and molasses. This will add some interesting notes to your brew so some experimentation will be required.
Honey – there are different ratios of sugar in different types of honey so you may see some contrasting results, but it can be used for experimentation. The main thing is DO NOT use raw honey for kombucha as the naturally present bacteria in the honey will compete with the SCOBY bacteria and we cannot guarantee which will win.
What sugars should I not be using in my brewing?
Raw honey - the naturally present bacteria in the honey will compete with the SCOBY bacteria and we cannot guarantee which will win. It’s ok to use raw honey in ginger beer.
Stevia – this is a plant sugar and will not ferment.
Artificial Sweeteners (Erythritol, Aspartame, Sucralose) – none of these will work.
There are lots of opportunities to get creative with your brewing. For kombucha the main recommendation we have is to get a good, strong SCOBY brew going and have a few back ups in case things don’t go so well the first time. Start with incremental amounts to get your SCOBY used to the new sugar sources and take it from there. We’re here to help so contact us if you have any further questions or comments.