Leave a glass and paper in the kitchen sink before vacation: why it's recommended

Returning home after a vacation can sometimes be met with the unwelcome surprise of unpleasant odors, often originating not from a lack of cleaning but from gradual processes in an unoccupied house. A simple, widely shared tip suggests leaving a glass inverted over a piece of paper placed in the kitchen sink to combat this.

The effectiveness of this method lies in its ability to preserve the water seal within the sink's siphon. This U-shaped pipe naturally retains water, forming a crucial barrier that prevents gases from the sewage system from entering the home. When a house is vacant for extended periods, especially in warm weather, this water can evaporate, compromising the seal and allowing odors to escape.

The glass-and-paper technique aims to slow this evaporation. The paper helps retain moisture, while the inverted glass reduces direct air circulation over the drain. By minimizing exposure to air, the water level in the siphon is maintained for longer, thus delaying the onset of unpleasant smells. This physical principle offers a low-tech solution to a common household issue.

Beyond the kitchen sink, maintaining water in other drains like those in bathrooms and showers is also recommended. Ensuring no blockages or food debris remain in the sink can further prevent odor issues. If persistent smells arise despite these precautions, it may indicate a more significant problem with the plumbing or ventilation system.