When you dream of seeing an alum in your dream it signifies the disappointment of something you were going to do as part of your scheme. When you dream of eating an alum it signifies how sorry you feel for something bad and harmful you did in the past for someone who did not deserve it. This dream represents your guilt and abomination you are suffering from. Make sure you redeem the mistakes you did and only then you will be able to live in peace.
Read more about dreaming of Alum in other dream meanings interpretations.