LAB ETHANOL that smells like RUM - (Nov/07/2013 )

So we have some 70% ethanol in the lab... and one batch of it smells VERY strongly like rum. As far as i can tell the most likely explanation is that it has formed an ester... (isobutyl propionate) but i am wondering if this is likely and/or how this reaction would happen, or if anyone has any other suggestions to solve this alcoholic mystery. And no, Capt jack sparrow has not been in the lab recently. 

Unlikely. Contaminated with an ester - yes. Formed an ester - no.

No idea about the ester formation, though this is a possibility in low grade ethanol preparations.  It is also possible that the batch of ethanol was prepared from the ingredients used to make rum, and then distilled down.