Cut the beetroot into cubes. Don’t grate it or it will ferment too quickly, producing alcohol. Put the beetroot into a clean 1-litre jar — you want the jar to be about half full with beets. Add your liquid, either the 2% brine or filtered water plus the starter and salt. Either way fill up the jar with liquid, making sure you leave 2.5cm of headspace at the top of the jar.

If you are not using a starter, let the kvass ferment at room temperature for up to three weeks. If you have used a starter, check it for taste after five days. When you are satisfied with the flavour, you can keep it in the refrigerator for up to six months. Drink diluted with water if you find the taste a little powerful at first.