Why Is It Unlucky To Spill Salt? I thought it may be interesting to post a superstition and its history once a week. So this week it will be Why is it unlucky to spill salt. There are two origins for this. The first is at the last supper Judas spilt salt. He was the one who later betrayed Jesus. It is said the Romans had started this superstition. The second comes from a time when salt was valued very highly. Infact, people were once payed in salt. So the spilling of salt was seen as a waste. Salt can also be used to divert bad luck. It started as throwing salt on an open fire while you would wish luck to an enemy. This has since turned into throwing spilled salt over over the left shoulder.