Experiment Disproves Chinese Tea Washing Custom

Numerous Chinese restaurants have eating utensils such as plates, cups, bowls, and chopsticks wrapped in clear plastic on tables all set for the use of their customers. When you sit down at a table, you tear the plastic off and then unwrap the chopsticks from their sealed cover. Subsequently, you will proceed to wash the eating utensils with hot tea that the waiter serves you along with a large metal bowl.

The Chinese have been following this custom for a long time, fully assured that it sterilises their eating utensils. As of now, to our knowledge, no one has ever sought to test this superstition until November 25, 2014, where two skeptical scientists from Ms. Tyler’s class conducted an experiment that led them to a shocking conclusion.

In the experiment, we used 8 cups from the school cafeteria to represent the eating utensils being used in the restaurants. We swabbed the interior of all cups with Q-tips for 5 seconds, and transferred the bacteria to their corresponding agar dishes for 10 seconds. We sealed the lids of all agar dishes with tape and set aside. Then we poured 100mL of 95°C distilled water into 4 cups and rolled it inside for 10 seconds. Following that we dumped the water down the sink, swabbed the interior of the cups using Q-tips for 5 seconds, and transferred the bacteria to their corresponding agar dishes. We did the same with 100mL of 95°C Iron Buddha Tea (very commonly served in local restaurants) using the remaining 4 cups and followed the aforementioned procedure. All agar dishes were put in a 35°C incubator for 2 days. After 2 days, the bacteria were counted by placing a sheet of graph paper beneath each agar dish and counting how many grids were covered by the bacteria colonies.

The result showed an unexpected trend: The bacteria count increased when washed with Iron Buddha tea while bacteria count plunged when washed with distilled water.

Disclaimer: this experiment was done with high school lab equipment— as such there was substantial room for errors and many variables were not faultlessly controlled. The above conclusion is merely a statement on the general trend suggested by the before and after data. While in the majority of the trials the bacteria count increased after washing with tea, the experiment needs to be redone with more trials and more variables under control so as to ensure consistency, accuracy and reliability. This experiment should not be taken as a solid and definite study; however, I still would not wash my eating utensils with tea in restaurants, having made the above observation personally.