Sayu means plain hot water in Japanese. Sayu is written like this: 白湯.
白 means “white,” and 湯 means “hot water.”
Recently, drinking Sayu has become popular among female Japanese entertainers as a method of weight loss and as part of an overall healthy lifestyle. They bring hot water in a thermos to studios and TV stations, and drink the hot water instead of tea, coffee, or soft drinks.
In addition to health and weight loss, they drink hot water to keep their teeth white. It also has a detox effect, and is good for weight loss as it raises the metabolism.
Drinking sayu is a health method that has been around for a long time, but it has gained in popularity recently due to a Japanese doctor named Dr. Makoto Hasumura.
Dr. Hasumura practices medicine at his clinic, Maharishi Minami Aoyama Clinic, in Minami Aoyama, Tokyo. He specialises in Ayurveda, a traditional alternative medicine from India, and recommends drinking sayu to his patients as a health method.
He published a book about sayu in 2010, 白湯 毒だし健康法: 体温を上げる魔法の飲み物 (The Plain Hot Water Detox Health Method: A Magic Drink that Raises your Temperature) which argues that drinking hot water is good for health as it raises the metabolism and increases digestion. The hot water should not be boiling, but should be moderately hot: between 50 and 60 celsius (between 122 F and 140 F). Some Japanese actresses who use this method include: Masami Nagasawa, Makiko Esumi, Haruna Kojima and Becky.
In January 2015, Dr. Hasumura had a talk with a popular model, Jessica Michibata, about his Ayurvedic method on ELLE Online. This talk happened due to Michibata’s earnest request, as Michibata has been an avid researcher of beauty methods. In addition to the talk, Dr. Hasumura provided her with his diagnosis from an Ayurvedic perspective, and gave her medical advice which she appreciated.
According to Dr. Makoto Hasumura, the way to make perfect sayu is as follows.
The only two things that you need are, clean water and a kettle.
You cannot use a microwave to make sayu, as the microwave destroys the balance in the water according Ayurvedic thinking.
First, heat a kettle with clean water on the stove. Dr. Hasumura says that mineral water, or tap water are fine to use, but if you use plain tap water, then a water filter is recommended. While boiling the water, it is preferred to turn on an overhead fan above the kettle in order to improve air circulation.
After the kettle begins boiling, take the lid of the kettle off, and continue heating the kettle for another 10 to 15 minutes. It is preferred to have the water boiling violently with big bubbles.
After 10 to 15 minutes, remove the kettle from the hot stove top and put it somewhere else to cool down naturally to the temperature that you should drink it at: around 50 to 60 celsius (between 122 F to 140 F).
Be careful not to burn your hand during the process, especially while lifting the lid off the kettle and the hot steam comes out.
Dr. Hasumura recommends to keep the sayu in a container such as a pot in your home. If you are planning to drink sayu while you are out, you should keep it in a thermos.
The daily recommended amount of sayu to drink is between 700 and 800 milliliters (five or six cups). However, he says that 700 to 800 milliliters of water per day is not enough to remain hydrated, so it is okay to drink other beverages such as tea, coffee, and water in addition to the sayu. He recommends drinking sayu first thing in the morning by sipping it slowly for around 5 to 10 minutes until you have finished drinking the whole cup (150 milliliters ). This leads to warm your stomach and intestines and lead to raise your metabolism. He claims that drinking too much sayu is not good for health either. He goes on to say that you should not drink more than the recommended amount per day as it has the possibility of creating an imbalance in your body.