We have a subscription fruits & veggie service called Odd Bunch. We always get lots of limes. So Rachael has requested a recipe for some sort of salted lime soda drink so we can use up the limes.

Chanh muối

This Vietnamese drink is made from salted, pickled limes.

Chanh muối
Chanh muối is a salted, pickled lime in Vietnamese cuisine. Its name comes from the Vietnamese words chanh and muối. To make the chanh muối, many limes are packed tightly in salt in a glass container and placed in the sun until they are pickled. During the process, juices are drawn off the limes, which dissolves the salt and produces a pickling liquid which immerses the finished chanh muối.
https://en.m.wikipedia.org/wiki/Chanh_muối
Chanh muối are used to make a drink (with added sugar and water or soda) called nước chanh muối
To prepare the drink, a small piece of chanh muối (containing both peel and flesh) is cut, placed in a glass, and crushed slightly with a spoon or other utensil to release its juices, then the other ingredients are added

Here’s a recipe for making the salted limes:

Vietnamese Salty Lime Soda (Chanh Muoi)
No doubt this recipe is not authentic, and I would love anyone who has a real Vietnamese grandmother to share the authentic version. But one of the nice things about multicultural Australia is the …
https://witcheskitchen.com.au/vietnamese-salty-lime-soda-chanh-muoi/

Nimbu Soda

This is an Indian-style lime soda I found from Serious Eats:

Nimbu Soda Is the Best Way to Quench Your Thirst
There may be no better drink for beating the heat than a nimbu soda, a lime-and-soda drink that's ubiquitous in India.
https://www.seriouseats.com/nimbu-soda

The tip is mixing the sugar and some salt into the lime juice before adding soda.

And, using Kala namak, a particular kind of black salt from India.