Direct Uptake of Nutrition and Caffeine Study: biscuit based comparative study

Objectives: To identify the time required to achieve optimal palatability of a cup of tea without risk of harm (oral scalding) using the resources available in a standard hospital staff room, and to identify the best accompanying biscuit for nutritional content, crunchiness, and integrity when dunking.

Design: Prospective, non-masked, biscuit based, comparative study.

Setting: Staff room in the surgery department of a UK hospital.

Participants: Four different varieties of round, non-chocolate biscuit: oat, digestive, rich tea, and shortie. A standardised cup of tea was determined on the basis of the investigators’ preference for colour and palatability and pragmatic tea making methods.

Main outcome measures: The main outcome was time to achieve a safe temperature for consumption of tea, and the best biscuit to pair with the tea on the basis of nutritional content, absorptive ability, crunchiness, and integrity after dunking. Biscuits were ranked first to last (according to scores 1-4), with penalty points given for adverse events such as scalds and breakability.

Results: Baseline data suggested that after adding 240 mL of freshly boiled water to an unwarmed mug containing a tea bag, the median temperature of a standard cup of tea was 82ºC (range 81-84ºC). Optimal palatability and agreed universal drinking temperature of 61ºC was achieved at 400 (range 360-420) seconds with 30 mL of cow’s milk and 370 (330-450) seconds with 40 mL of milk. The investigators considered tea colour preferable with 40 mL of milk.

Conclusion: Healthcare workers can safely consume a cup of tea after less than 10 minutes, especially if enjoyed with a biscuit. Making time for a cup of tea may help healthcare workers avoid their break point.