British healthcare workers can safely drink a cup of tea in ten minutes, especially if they dip a biscuit in it. With 240 milliliters of tea water, the drinkable temperature of 61 degrees Celsius is reached in 370 seconds on average with the addition of 40 milliliters of milk. Of the four biscuits tested, an oat biscuit offers the best combination of nutritional value, cooling time and the breaking point at baptism, among other things.
Two doctors from a Welsh children’s hospital showed this in research that appeared in the special Christmas issue of the scientific The BMJ (formerly British Medical Journal).
The researchers first determined that tea is safe to drink at 61 degrees and did a refresher course in good cuppa preparation (GCP). They poured 240 ml of boiling water into an unheated mug with a tea bag, after which the tea averaged 82 degrees. They stirred the bag with a metal spoon for 60 seconds, pressed the bag, removed it from the mug, poured 40 ml of semi-skimmed milk from a refrigerator at 4 degrees and started the stopwatch. Every thirty seconds they slurped some tea, with the risk of burning their tongues. After an average of 370 seconds, more than six minutes, the tea was safe to drink.
Four kinds of biscuits
The experiment was also done with 30 ml of milk, but after a pilot, 40 ml was chosen for testing: the researchers preferred the color the tea takes on with 40 ml of milk. The time for boiling water and making tea was not included. It also turned out that no standardized method could be found, suitable for a modern working environment.
When the stopwatch was started, four types of biscuits were dipped in the tea in six sessions to see how many seconds the cooling time could be shortened. The digestive did that fastest, with 240 seconds Time to Drinkable Tea (TTDT), then the oatmeal cookie (270 seconds). The hypothesis was that the most absorbent biscuits would push the TTDT, but a dripped Rich Tea biscuit left the most tea on a paper towel. The oat biscuit was the last to break in half when dipped in the tea (both in and out of the tea). It also had the most calories: beneficial in hospitals, where staff are more likely to eat too little than too much.
Proper hydration and nutrition are fundamental, if only to avoid getting ‘hangry’ (hungry and grumpy), the authors write. Optimal fluid and energy intake is essential for peak performance of healthcare personnel.
The approach of this small study, and of this entire Christmas issue of BMJ, may be playful and humorous, there is certainly a serious undertone in one sentence: these are tough times for the British public sector, especially since the corona pandemic. And this article does not even mention the strikes of about a hundred thousand nurses and a significant increase in the number of flu admissions in the past month. “We have seen employees skip breaks due to lack of time.”
Although the doctors investigated a distinctly British custom, the experiment could also be relevant for countries where tea is drunk without milk. A shortcoming in the study is that the cooling time was not measured with tea without milk.
A version of this article also appeared in the December 29, 2022 newspaper