Wash two half pint mason jars well with warm soapy water. Rinse well.
Use scissors to cut the spiralized beets into smaller, bite-sized strands. Place them into a large bowl and sprinkle over the salt. Massage with your hands for about five minutes until they release a bit of liquid. You can use your bare hands, the beet juice washes off easily, or slip them into plastic bags if you’re worried about dying them.
Pack the beets into the mason jars, tossing in a few leaves of dill from time to time. Squish the beets down to ensure that the juice covers them entirely. If not, you can make a brine of ¼ cup (60 ml) filtered water (don’t use tap water) and a pinch of sea salt. Add as much as is necessary to submerge the beets completely.
Take a leftover end of a beet from the spiralizer (the bit that looks like a mushroom), turn it upside down and wedge it into the jar, “stem” sticking up. This is to hold the beets down in the jar and ensure that they maintain submerged. If it’s not working, you’ll have to find something heavy. You can boil rocks and put them on top (seriously).
Cover the jars with a towel and leave to ferment. Begin checking them after a couple of days to ensure that the beets are still submerged, add more brine if necessary, and taste to see how they’re doing. They may develop a bit of scum on top, scoop it off, it’s harmless.
You can eat them when they have enough sourness for your taste. They will continue to sour until you’re ready to eat them or put them in the fridge to maintain their level of sourness.