My double sink backed up with brown, nasty water with bits of food waste 2 days ago. It shoots out the overflow and comes up and down in both sides of the sink when I run the garbage disposer. I tried a commercial drain cleaner to no avail. Hours later, my husband took it apart and ran a snake down and didn't find a clog as far as the snake would go. Our kitchen is directly over our laundry room - don't seem to be having issues down there.

I had wedged a new wood shelf under the garbage disposal side that day, but had been using the sink with no problems until hours later. Could I possibly have accidentally turned a handle under the sink that would cause this back-up? :confused: The bathrooms 20 feet or so away upstairs and down don't seem to be affected by the clog at the moment. The house is 30 years old.

The wedge was just a coincidence, not related to your drain. Your hubby needs a longer snake, he might also try roding up from below.

Where did Hubby snake from? The trap. ( it is "P" trap isn't it?) or the kitchen roof vent? Back to you, Tom