What would cause rotten food smell in kitchen drains?

Answer 1

Hydrogen sulfide, a very dangerous gas, is produced in sewers from bacterial action. That gas can travel back up through a drain that is not equipped with an effective trap. The sink's trap blocks the path with a U-shaped loop of pipe that remains filled with water.

• The water can be siphoned out of the trap if the Plumbing is not properly vented. If you flush the toilet and you hear a slurping sound in the sink or, if you drain the sink and you hear a slurp at the end, it is time to call a plumber to inspect your pipes and and remove whatever debris might be blocking the vent stack. Birds will sometimes try building nests in them.

• The water in the trap can dry out if the drain has not been used for a very long time. If you are going to leave a house unoccupied for months at a time, a tablespoon or two of vegetable oil down all the drains will slow evaporation. If there is a chance of the pipes freezing, a bit of automotive or RV antifreeze will not only keep the traps from drying out but it will also keep the drain pipes from bursting. Use about a half-cup in a kitchen sink, a quarter-cup in a bathroom sink or bath tub or shower and a cup in a toilet.

Answer 2

Exactly that, rotten food. Purchase some drain cleaner and follow directions. Food leaves some bacteria in the pipes of kitchen sinks. Of course it shouldnt, reality is that it does. 3 or 4 times per year I use drain cleaner and the smell goes away.