I can’t believe that this recipe for a fermented lemon lime soda is my SIXTH fermented soda post. But I was so pleasantly surprised with how delicious my first attempt turned out, a fermented blueberry soda, that I’ve just kept making them. And I’ll probably continue to make more.
Which is a little weird, I admit, for a site that has a lot of blogs about digestive health and the dangers of sugar.
But real, fermented soda, made with real fruit and organic sugar is a totally different animal than conventional flavored sodas, like, oh, I don’t know, Sprite and 7 Up, two of the largest sellers of lemon-lime flavored soda.
Flavored sodas use “natural flavors” which are created in labs and really aren’t that natural at all (check out the cover pic example in this link).
So for starters, in the recipe below for a fermented lemon lime soda, I actually use REAL lemon and lime juice.
Yeah I’m such a rebel.
Nor does it contain genetically modified high fructose corn syrup or other common lists of preservatives and chemicals that you’ll find in most mass-produced sodas.
And get this. It also contains actual health benefits. My fermented blueberry soda discusses some of those benefits.
1. Make fermented lemon lime soda as lemony or limey as you want.
In the recipe below I split the lemon and lime juice into equal amounts. I used 3/4 cup of each one. But I also made two separate batches of JUST a lemon soda and just a lime soda. The differences in taste were pretty subtle between all three. If you prefer lemon instead of lime, use more lemon juice compared to lime juice or just use all lemon juice (or vice versa). It’s totally up to you.
2. Make the lemon and lime juice yourself and don’t use the concentrated bottled stuff.
Those little bottles that contain lemon and lime juice concentrates are way too, well, concentrated. So yes, that means you have to squeeze the juice out of actual real lemons and limes. Don’t roll your eyes! It doesn’t take that much time. A simple electric citrus juicer or an even simpler citrus press will certainly help speed the process.
Also, a typical whole lime will give you about a 1/4 cup of juice. A typical lemon might give you a little more than that. So in the recipe below you’ll need about 3 limes and lemons.
3. There are several options for starter cultures
A starter culture is necessary to kick-start the fermentation process. There are a few types of liquid starter cultures as well a yeast-based starter that comes in dried form.
My preferred starter culture is a ginger bug. I love the flavor it gives to fermented sodas. My friends over at Oh Lardy! have a great post for how to make a ginger bug.
It does take 5-7 days to prepare a ginger bug though. Another option is water kefir which also takes some time to prepare. If you don’t want to wait that long, you can use whey, which only takes a few hours to make from whole milk yogurt.
Another option is 1/8 of a teaspoon of dried champagne yeast, which comes in a small packet.
Starter cultures introduce the bacteria that will ferment the sugar and as a result, naturally carbonate the soda. Trapping the carbon dioxide in the soda bottles is what gives a fermented lemon lime soda (and all fermented sodas) a natural fizz.
But you have to be careful.
4. Use the right type of glass soda bottles and check your soda EVERY DAY.
This is VERY important. As I showed in my fermented cream soda post, if you use a poor quality bottle and are careless, bottles can explode. Some types of glass bottles are better than others. These are the best:
These bottles are built soundly and stand up well to the pressure that will build from the fermentation process. Regardless, you still need to check and release the pressure every day to prevent the bottles from exploding as pressure can build rapidly, especially in warmer weather.
To prevent any possibility of exploding glass, you could certainly use plastic bottles too. Personally, I don’t like to use plastic but I know some people who do just to be on the safe side.
Another option if you’re going to use glass bottles is to also use one small plastic bottle as a gauge of pressure. As pressure builds, the plastic will expand and you can feel the increased pressure when you squeeze the bottle. This will help you know when to open the glass bottles to let the pressure out.
Simply add lemon juice, lime juice, water, sugar and a starter culture and in a few days you'll get a lemon-lime soda!
For more lacto-fermented soda recipes:
Craig Fear is the creator of Fearless Eating and the author of three books, The 30-Day Heartburn Solution, Fearless Broths and Soups and The Thai Soup Secret. After years helping clients with digestive issues, Craig decided to pursue writing full-time. He intends to write many more books on broths and soups from around the world! Click here to learn more about Craig.