I buy all my olive oil in bulk at a large supplier here in Pittsburgh. This place probably sells hundreds of gallons every Saturday. I have never seen this issue before. We filled a 1 gallon glass bottle to about 1 inch from the top and use a screw top cap on it. When we got home my wife said the top must not have been on tight because the bag was wet from oil. When she went to tighten the cap it was pretty tight. She wiped the bottle and we went back out shopping. About an hour later when we got home there was oil on the counter around the bottle. After looking close I could see oil running out of the cap. I took the cap off and saw the oil had expanded and was now forcing its way out the cap. I emptied about an inch out and it rose a quarter inch again in the next couple of hours. Overnight it did not change. Has anyone ever heard of this? My wife has been in the food industry all her life and never experienced this. The oil smells, tastes, and looks normal.
