How do you stop boiled beetroot going mouldy?

To prevent boiled beetroot from going mouldy, ensure it is cooled quickly after cooking and stored in an airtight container in the refrigerator. Additionally, you can submerge the beetroot in vinegar or brine, which acts as a natural preservative. Make sure to use clean utensils when handling the beetroot to minimize contamination. Lastly, consume it within a week for optimal freshness.