Fermented lemonade - 2-way carbonated

First of all for all people who are confused about soda versus lemonade a simple bullet point characterization:

Soda

• Quite sweet
• Can have basically any flavor
• Carbonated
• Usually clear
• The overall characterizing aroma comes from the original "flavor" which is augmented from the sugar and balanced by citric acid or another flavorless acid.

Lemonade

• Medium sweetness - more on the tart side
• Basic flavor is... lemon (because of LEMONade)
• Normally not carbonated
• Cloudy
• The overall characteristic comes from the lemons (and sometimes other fruits) which are balanced with sugar. Acid comes part or mainly from the lemon.

I quite enjoy both - more often soda, but lemonade is also refreshing. But then there are drinks like Pellegrino Limonata, which has the refreshing fizz of soda, but also includes lemon juice, which taste more natural.

Off course, all commercial products taste a bit off, due to the fact, that most juices are degrading (that's why soda is using usually not fresh juice but natural aromas). 

But homemade fizzy lemonade is a treat.

Fermentation

Fermentation can be a bit challenging - especially when it comes to flavors. You don't want to ferment with yeast - it will result into far too much alcohol - plus your bev taste yeasty and fermenty.

I found, that water-kefir is a magical stick for all your applications... you ferment the sugar, which makes it a bit more healthy. It gets additional aromas, but it won't taste too funky. There will no or very very less alcohol. So all good.

In this application I won't ferment the lemon with the water-kefir - I will simply make aroma-less (1st ferment) water kefir, and after about 2 days at room temperature and 1 day in the fridge (or more in the fridge) I will add lemon juice and drink it...

This turns awesome. I used for 1l about 1½ lemons - which results into a tart but not too tart beverage.

But my first try had very little area of improvement. So I thought: sodium citrate... well in most commercial products, you will find sodium citrate. It is an acid balancer... In our application you don't even have to buy it:

Add just 2 lemons (½ lemon more) into the bottle then add a pinch of sodium bicarbonate into the lid and close the bottle extremely quickly. I really suggest, that you are using a soda PET bottle, as the pressure seems to be pretty high. The baking soda is reacting with the acidity of the lemons and will result for more carbon dioxide (because we like extra carbonation) and... sodium citrate (here we are). Hence your lemonade will be super fizzy and not too sour - yet lemony.

1l      plain water kefir
2       lemons
1       pinch of bicarbonate of soda

 This might be just the simplest recipe ever, if you already have water kefir.