An expert chemist's guide to brewing the perfect cup of tea
According to Michelle Francl, professor of chemistry at Bryn Mawr College in Pennsylvania, USA and author of Steeped: The Chemistry of Tea , brewing tea is a rich chemical process involving hundreds of compounds that influence the colour, aroma, taste and even health benefits of every cup.
'Tea is the world's most popular beverage. What many people don't realise is how complex the chemistry behind it truly is,' she said.
While most South Africans reach for red Rooibos, the green, unfermented version actually has higher antioxidant levels.
'Fermented Rooibos has fewer antioxidants, because the fermentation process is essentially an oxidation process. Antioxidants act like little sponges soaking up oxygen. Once they've reacted, they can't function as antioxidants anymore,' Francl,added.
Green Rooibos retains more aspalathin, a rare and potent antioxidant unique to the plant, but one that degrades with time and oxygen. Her advice? 'Drink it fresh.'
Francl also cautions against using mineral-heavy water. In teas made from Camellia sinensis, it can result in 'tea scum' – a layer of compounds floating on top of your brew. She suspects something similar may occur with Rooibos if the water is particularly hard.
'These mineral-polyphenol interactions can dull flavour, while filtered water can help preserve the taste profile.'
Many Rooibos drinkers report that longer steeping enhances sweetness. Though there's no formal analysis to confirm this, Francl says it's plausible.
'Longer steep times increase the presence of maltol, a natural flavour enhancer and vanillin, the same compound that gives vanilla its signature sweetness.'
To brew the ultimate cup of Rooibos, Francl recommends the following: Use green Rooibos if your goal is to maximise antioxidant intake
Choose fresh Rooibos to retain aspalathin content
Use boiling water (100°C)
Steep for 10 minutes
If possible, opt for filtered water to avoid flavour-dulling minerals
Whether you're sipping Rooibos to unwind after a long day or seeking its health benefits, knowing the science behind the steep can elevate your tea ritual. As Francl so elegantly puts it, 'Brewing tea is not just an art. It's a beautifully balanced act of chemistry.' So next time you brew a cup, give it the full ten minutes and let science do the rest.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Eyewitness News
15 hours ago
- Eyewitness News
Joburg law enforcement urged to intervene in protests preventing foreign nationals from accessing healthcare
JOHANNESBURG - The deputy chairperson of the Johannesburg Migrant Advisory Panel is calling on law enforcement officials to intervene in ongoing protests preventing foreign nationals from receiving healthcare. Over the past week, there have been several protests staged at clinics across the metro. Protesters who were at the Rosettenville Clinic on Friday said they would not stop until South Africans were prioritised for healthcare. Siji Olorunsola has urged people to abide by the law. "According to what we've seen is that's wrong. When the law says that everybody in South Africa should have access to healthcare, they should be given the privilege to access it. And that's what the law says. So, if you are gatekeeping now and disallow people to come in, then that's another thing entirely."
Eyewitness News
19 hours ago
- Eyewitness News
Rosettenville residents block foreign nationals from accessing healthcare services
JOHANNESBURG - Some community members in Rosettenville, in southern Johannesburg, are staging a protest blocking foreign nationals from accessing healthcare services. There have been multiple protests of a similar nature across the metro in several clinics for about a week. Community members said South Africans must be prioritised because resources are limited for citizens. Several residents are at the Rosettenville Clinic entrance, standing as guards. All patients who come to get help from the facility are stopped and asked for documentation, or they are asked to speak their mother tongue to determine if they are South Africans. 'One foreign national has one ID document for about 20 people. Or they make their documentation from internet cafés? We need to put South Africans first,' said protester Ndiphiwe Mdebuka. Mdebuka said they will continue to block entry until they are heard.
The Star
2 days ago
- The Star
An expert chemist's guide to brewing the perfect cup of tea
When it comes to crafting the perfect cup of tea, lovers of the brew know it's as much about flavour and ritual as it is about comfort and connection. From black to green, oolong to herbal, every cup tells a story. But what if we told you that behind the soothing steam and fragrant leaves lies a world of chemistry – one that can actually help you brew a better, more flavourful cup? According to Michelle Francl, professor of chemistry at Bryn Mawr College in Pennsylvania, USA and author of Steeped: The Chemistry of Tea , brewing tea is a rich chemical process involving hundreds of compounds that influence the colour, aroma, taste and even health benefits of every cup. 'Tea is the world's most popular beverage. What many people don't realise is how complex the chemistry behind it truly is,' she said. While most South Africans reach for red Rooibos, the green, unfermented version actually has higher antioxidant levels. 'Fermented Rooibos has fewer antioxidants, because the fermentation process is essentially an oxidation process. Antioxidants act like little sponges soaking up oxygen. Once they've reacted, they can't function as antioxidants anymore,' Francl,added. Green Rooibos retains more aspalathin, a rare and potent antioxidant unique to the plant, but one that degrades with time and oxygen. Her advice? 'Drink it fresh.' Francl also cautions against using mineral-heavy water. In teas made from Camellia sinensis, it can result in 'tea scum' – a layer of compounds floating on top of your brew. She suspects something similar may occur with Rooibos if the water is particularly hard. 'These mineral-polyphenol interactions can dull flavour, while filtered water can help preserve the taste profile.' Many Rooibos drinkers report that longer steeping enhances sweetness. Though there's no formal analysis to confirm this, Francl says it's plausible. 'Longer steep times increase the presence of maltol, a natural flavour enhancer and vanillin, the same compound that gives vanilla its signature sweetness.' To brew the ultimate cup of Rooibos, Francl recommends the following: Use green Rooibos if your goal is to maximise antioxidant intake Choose fresh Rooibos to retain aspalathin content Use boiling water (100°C) Steep for 10 minutes If possible, opt for filtered water to avoid flavour-dulling minerals Whether you're sipping Rooibos to unwind after a long day or seeking its health benefits, knowing the science behind the steep can elevate your tea ritual. As Francl so elegantly puts it, 'Brewing tea is not just an art. It's a beautifully balanced act of chemistry.' So next time you brew a cup, give it the full ten minutes and let science do the rest.
