Cut the carrots into sticks and place them in a large glass mason jar.
Add the lemongrass, thai chilis, ginger and garlic to the jar with the carrots.
Make the salt water brine by mixing ½ cup of warm water with the salt and stir until the salt has dissolved. Add the remaining water to the salt water once the salt has dissolved.
Pour the brine into the jar with the carrots. There should be enough to submerge the carrots under the brine. If not, make more brine and add it to the jar.
Cover the jar loosely with a lid and store in a cool, dry place away from direct sunlight for 3-7 days.
Once the brine is cloudy, try a carrot to see if it’s ready. It should be sour, but still crunchy.
Store in the refrigerator for up to a month.