Need to calm down? There’s a science to brewing the perfect post-Swiftposium cuppa

Taytay loves her teatime (and “everybody agrees”), but did you know that the perfect cup is not luck, it’s both an art and a science.

By A/Prof Senaka Ranadheera, The University of Melbourne

Taylor Swift is not alone in her fondness for tea, in fact tea is the world’s most popular beverage (after water). So if you’re looking to do as Taylor does and take some time out for yourself with a good cuppa, read on to understand how to brew the perfect cup.

Tea has become a motif for Taylor, appearing in both her lyrics (see London Boy, Seven, Gold Rush and Anti-Hero) and her music videos (eg: Look What you Made Me Do). This has inspired countless memes and even her own Midnights-themed tea cups.

But, while tea is popular with Taylor – and the rest of the world – brewing the perfect cup is not as simple as hot water with a tea bag… there are many factors that influence the quality and flavour of tea. So, if you’re one of those who enjoy a cuppa (or “sweet tea in the summer”), read on to ensure you save yourself from the “gray of your day-old tea”.

Tea comes in many different types, including black, green, oolong and white. These varieties come from the young, tender, and freshly picked leaves of a plant called Camellia sinensis and the main difference between these types is the processing method. For example, black tea (the most popular type worldwide), is produced through a complete fermentation process, whereas green tea is a non-fermented product.

We have been consuming tea for centuries and not only is tea hugely popular; brewing tea is embedded in the traditions and culture of many societies, for example tea is not only used as a tool for social bonding (offering a cuppa to your guests), but it is also a comfort ritual (popping the kettle on when times are tough).

It also has many health benefits. It’s frequently referred to as a ‘mood food’ – and for good reason. The caffeine in tea contributes to the mood-enhancing and stimulating effects, and tea has been shown to improve mood and cognition (1). Tea also offers health benefits due to its antioxidant properties (2), potential as an anti-inflammatory (3) and ability to reduce the risk of heart disease (4), diabetes (5), obesity (6) and even cancer (7).

The ‘magic’ behind tea’s health benefits lies in the bioactive compounds that are found in tea leaves. A prime example is polyphenols, which is a naturally occurring chemical compound. These polyphenols – the major one being ‘catechins’ (8) – can fight the free radicals produced in our body, which are responsible for many health problems.

So, how do you brew the perfect cup of tea?

1. It begins with the leaves

Firstly, the time of harvesting affects the characteristics of each type of tea. White teas are produced from early harvested young leaves, which, in addition to their minimal processing, makes ‘lighter’ than green and black teas. As any tea drinker knows, the type of tea leaf dramatically affects the taste of teas and this varies by person and culture.

The flavour of tea varies depending on many factors, including the quality and size of tea leaves. This largely relates to where the tea leaves are harvested, and how they are grown and processed. While you can’t directly control these factors, you can investigate the source of the tea leaves either through the packaging or with the manufacturer directly, giving you the information you need to narrow down your brand of choice).

2. Brewing is key
The process of brewing also influences the tea’s flavour and understanding the science behind tea brewing can help you to make that perfect cuppa for your post-Eras winddown.

Tea polyphenols, caffeine and other compounds in tea leaves, when released into hot water contribute to the flavour of tea, so the longer you brew the more bioactives you get and the stronger the taste. However, brewing time also influences the level of tannins (polyphenolic compound) in your tea, which can make your tea bitter.

Brewing black and oolong tea for about 4-5 minutes in hot or boiling water (98-100oC) will help to extract suitable amounts of tea compounds to release maximum flavours, while slightly lower temperatures ~82oC for 4-15 minutes are used for green tea. The recommended temperature differs because higher temperatures release more tannins. While green tea has lower levels of tannins compared to black tea, lower brewing temperatures will help to preserve its unique pleasant flavours.

3. Pay attention to the water
Pre-heating your mug with some hot water can help to maintain water temperature during brewing, which is a good idea as temperature fluctuation can affect the extraction process.

Surprisingly, although for many cups of tea the only other ingredient is water, this can actually have a big impact on the final product. Using ‘soft’ or ‘pure’ water is always better than using ‘hard’ water, as chemicals such as calcium affect the extraction process during brewing.

Heating up your cuppa using a microwave may be sacrilegious for tea purists, but is gaining in popularity, especially in the United States. Research suggests the microwave can enhance the bioactive levels, as long as the tea bag or loose leaves remain in the cup during heating. However, one study by Chinese researchers suggests that microwaving causes the water to heat unevenly, negatively influence the taste. It’s also worth noting that Taylor bucks the trend and uses a kettle.

While the research-backed evidence for this is a little thin, tea experts also recommend never using re-boiled water as re-boiling removes oxygen from the water, which is considered vital for releasing the flavour in your favourite tea.

4. Milk matters

Adding milk to black tea is a common habit in the many parts of the world and there is some debate over whether to add milk first or last? Experts advise pouring milk into the cup first followed by the tea. This relates to the temperature of the milk, which reaches a higher temperature if added to the boiling tea than it does when the tea is added to the cooler milk. This influences the flavour by preventing denaturation of milk proteins, meaning your cuppa maintains a smooth, pleasant flavour.

5.Sweet tea in the summer
Adding sweeteners like sugar and honey lowers the antioxidant potential of tea, but stevia – a sweet-tasting plan does not, so may be a better option (and has the added benefit of fewer calories).
Lemon can also be beneficial, with the acid helping to extract beneficial tea bioactives, so if you want to add lemon to your cuppa, it may be beneficial to do so before removing the teabag.

And finally, as you head to the kitchen equipped with the knowledge to brew your perfect cup of tea, remember to store your leaves carefully so they don’t damage – avoid light, heat, moisture, odour and air. Now, put your feet up, pop on your favourite Taylor Swift song and enjoy!

References

1.Dietz, C., & Dekker, M. (2017). Effect of green tea phytochemicals on mood and cognition. Current pharmaceutical design, 23(19), 2876-2905.
2.Senanayake, S. N. (2013). Green tea extract: Chemistry, antioxidant properties and food applications–A review. Journal of functional foods, 5(4), 1529-1541.
3.Lin, F. J., Wei, X. L., Liu, H. Y., Li, H., Xia, Y., Wu, D. T., ... & Gan, R. Y. (2021). State-of-the-art review of dark tea: From chemistry to health benefits. Trends in Food Science & Technology, 109, 126-138.
4.Hartley, L., Flowers, N., Holmes, J., Clarke, A., Stranges, S., Hooper, L., & Rees, K. (2013). Green and black tea for the primary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews, (6).
5.Chen, Y., Li, W., Qiu, S., Vladmir, C., Xu, X., Wang, X., ... & Sun, Z. (2020). Tea consumption and risk of diabetes in the Chinese population: a multi-centre, cross-sectional study. British Journal of Nutrition, 123(4), 428-436.
6.Lin, F. J., Wei, X. L., Liu, H. Y., Li, H., Xia, Y., Wu, D. T., ... & Gan, R. Y. (2021). State-of-the-art review of dark tea: From chemistry to health benefits. Trends in Food Science & Technology, 109, 126-138.
7.Cheng, Z., Zhang, Z., Han, Y., Wang, J., Wang, Y., Chen, X., ... & Wu, Z. (2020). A review on anti-cancer effect of green tea catechins. Journal of functional foods, 74, 104172.
8.Dubeau, S., Samson, G., & Tajmir-Riahi, H. A. (2010). Dual effect of milk on the antioxidant capacity of green, Darjeeling, and English breakfast teas. Food Chemistry, 122(3), 539-545.