Possible Fuel Contamination

For the racers using Alcohol to fuel your race car, especially with a carb. My AMX is crackling and popping a little bit while making a pass. It doesn't appear to be effecting the et of the car. But you can defiantly hear it. Most of my alcohol is stored in the metal drum and sealed. It's also not on the floor. I keep 20 gallons in 5 gallon fuel jugs in the trailer. Some of it has been in the trailer for a couple of months. I know alcohol is hydroscopic. Is it possible that the alcohol that I store in the trailer has become contaminated with water? Have any of you guys ever experienced you alcohol being contaminated with water? Can you test for that? If so how?