We wash dishes with hot soapy water for several reasons, as the heat and soap work together to enhance the cleaning process:
Grease and Oil Dissolution: Hot water helps to dissolve grease, oil, and food residues more effectively than cold water. When grease and oil are heated, they become less viscous, making it easier for the soap to break them down and lift them off the dishes.
Increased Surface Tension: Hot water has lower surface tension compared to cold water. Lower surface tension means that hot soapy water can spread more easily and cover a larger area on the dishes, helping to reach and clean tight spaces and corners.
Enhanced Soap Activity: Heat increases the activity of soap molecules, making them more efficient at breaking down and lifting away dirt, food particles, and bacteria from the dishes' surfaces.
Bacteria Elimination: Hot water can help to kill or reduce the number of harmful bacteria present on the dishes. Although hot water from a typical household water heater may not be hot enough to sterilize the dishes completely, it can still aid in reducing bacterial contamination.
Comfort and Speed: Using hot water can make dishwashing a more comfortable and faster task, as warm water is more pleasant to work with, and it can help to soften and remove dried-on food residues more easily.
However, it's essential to strike a balance when using hot water, as excessively hot water can damage some types of dishes, particularly delicate items or those made of certain materials. Additionally, when washing dishes by hand, it's crucial to be cautious to avoid scalding yourself with hot water.
Overall, using hot soapy water when washing dishes can improve cleaning efficiency, help remove stubborn residues, and contribute to better hygiene in the kitchen.