Factors which are already known to influence tea including brewing temperature, vessel, time, and the water-to-leaf ratio were all matched in each test. (Shutterstock/-)
New US research has found that green tea drinkers can benefit from more of the drink’s antioxidants if they brew the drink using bottled water rather than tap water, although more antioxidants also leads to a more bitter taste.
Carried out by researchers at the Department of Food Science at Cornell University, the new study recruited more than 100 consumers and carried out a series of tests at Cornell’s Sensory Evaluation Centre.
Participants were asked to taste black and green tea which had been brewed with bottled, tap, and deionized water. Factors which are already known to influence tea including brewing temperature, vessel, time, and the water-to-leaf ratio were all matched in each test.
The researchers also measured the tea’s antioxidant Epigallocatechin Gallate (EGCG) content.
The findings, published in the journal Nutrients, showed that the type of water used significantly affected the taste of green tea, with the participants preferring green tea when it was brewed using tap water rather than bottled water because it produced a sweeter taste.
However, what is lost in flavor is made up for in health benefits. Brewing green tea with bottled water also led to around double the amount of EGCG, which is what causes the bitter taste.
“If you’re drinking green tea for its health properties, you should be using bottled water,” said Robin Dando, Cornell associate professor of food science, “If you’re drinking tea for taste, tap water is better.”
The participants could not taste the difference between black tea brewed with either tap or bottled water, with the study’s lead author Melanie Franks adding, “The average consumer for black tea isn’t able to tell the difference. Whether it was tap water or bottled water, the taste differences are too subtle.”
Dando believes that the everyday minerals found in tap water, such as calcium, iron, magnesium, sodium and copper, are what causes the brewed green tea to result in lower levels of EGCG.
“Bottled water — where calcium or magnesium have been filtered out and where the iron concentration is brought down a notch — is able to extract the EGCG more efficiently,” said Dando. “With purer water, you get more health benefits out of the tea.”