Thoroughly clean and sterilize the container and utensils you will be using.
Wash, drain and then cut your beets into disks, halves or quarters. Optionally, you can grate, slice, shred or chop the beets into a non-metal bowl. You can do this by hand or with a food processor. Pieces should be about the size of a quarter, or smaller. (I prefer a coarse shred.)
With a wooden spoon, mix the grated beets with sea salt, to taste.
Add caraway seeds either whole or crushed. Crushed caraway seeds give a more intense flavor.
Pack the beets firmly and evenly into a clean crock, glass jar or enamel container until liquid comes out of the beets freely. Leave 2 inches of room at the top of a jar or 4-5 inches of room at the top of a crock. Make sure juice covers the beets completely!
Once beets are immersed, place fermentation weights into the jar or crock. If you don't have weights, put a plate on top of the beets (if using a crock) and a large freezer bag filled with water on top of the plate. (I use 2 large bags, one inside the other so that if the bag breaks, it will not water down the beets into a tasteless mess.)
Latch or screw the lid down loosely. Or use an airlock fermentation lid. The beets must be completely submerged so no air can get in and contaminate the them with unwanted yeasts or molds!
Put jar or crock in a cool area where the temperature will be around 75 degrees. Fermentation will begin within a day, depending upon the room temperature. If temperature too high or too low, the beets may not ferment and could spoil!
Cover the container with a clean towel and check after 2 days, releasing some of the carbon dioxide that has built up inside. Scoop any scum off the top (it is harmless), and repack. Check every 3 days and repeat as necessary.
After 2 weeks, sample the beets to see if they taste ready to eat. The flavor will continue to mature for the next several weeks. Refrigerating the beets will extend their shelf life.