I was having the same issue - dishes and glassware coming out with a stale, sour water smell if we did not immediately empty the dishwasher after washing. This started about 3 mos. after purchase and installation. Tried citric acid (active ingredient in Affresh), which only temporarily helped, running the disposal with hot soapy water pbefore a cycle, vinegar in the sanitize cycle, cleaning the basket, etc. Minimal to no improvement. I was going mad!
Finally - I solved it. I read a comment here discussing the high loop and this being an installation requirement. I confirmed we had one (we did), got out the manual, read about how the hoses must be positioned and realize the hose running from dishwasher over the cabinet and down to the disposal was too long and sagging! Thus dirty disposal/dishwasher water was sitting/backing up and turning rancid.
The manual says the hose connecting to disposal must be affixed high up on the underside of the sink. Lowes had left ours hanging low. The solution was to wrap a zip tie with screw hole around the hose and screw it into the upper part of the sink cabinet.
Problem solved! No more frustrating stink! Our dishwasher is now good as new. Simple fix!
