How to make the best cup of tea (according to science)

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With the sheer variety of tea traditions and preferences around the world, is there really a best way to make tea? Just look at Tibetan butter tea, which is made with yak’s milk, or tea in Morocco that’s typically prepared with green tea, sugar, and mint.

Beau-tea might be in the eye of the beholder, but science and centuries of tea drinking have taught us a thing or two about how tea preparation affects taste, aroma, and health properties.

Because adding milk and other ingredients to tea is largely up to personal taste, let’s focus on how to steep the best cup of pure tea without all the add-ins.

The best way to make tea

From your teacup’s material to how much room your tea leaves have to expand, there are a surprising number of factors that influence how tea tastes and how to properly make tea.

1. Choose a smooth glass, ceramic, or porcelain cup

Whatever you do, steer clear of Styrofoam cups, which absorb flavor and leave a less robust brew [12].

And while tempting for their cozy campground vibes, stainless steel mugs are also flavor sucking culprits due to their porous properties. In addition, steel has high heat conductivity, meaning the liquid inside will cool down rather quickly [1].

In comparison, glass followed by ceramic as a mug material retains heat for a longer time, so your tea stays warmer, longer [2]. Another benefit of using glass, ceramic, and even porcelain teacups and mugs for tea is that the glazed finish prevents the tea from seeping into the material and changing the taste profile no matter what kind of tea you use.

The same study also found that the cup texture can affect the perceived taste of tea [2]. For example, tea drunk from a rough finished mug can taste more acidic, drying, and rough than from a smooth mug.

The verdict? Use a smooth, glass mug for tea if you have one handy for the best tasting tea.

2. Use filtered water

Sometimes, a thin film of what looks like oil or grime forms at the top of a cup of tea.

One reason is that the calcium carbonate in hard (or unfiltered) water reacts with tea leaves to leave nasty looking residue behind [3].

The solution is to stick to filtered water to keep out large amounts of minerals that can alter the look and taste of the tea.

What do you need to steep loose leaf tea?

Loose leaf tea can be intimidating to first-timers, but steeping these little leaves is as easy as just having a steeper or infuser handy.

Infusers come in all shapes, materials, and sizes, but a good rule of thumb is to give tea leaves the most room possible to expand and swish around to extract all the good stuff out of them. Tiny metal tea balls or fun animal shaped tea infusers are cute, but don’t give tea leaves the room they need.

If you don’t have an infuser handy, there are tons of other ways to create your own with things around the kitchen.

steel ball infuser — Small infusers like this one don’t give tea leaves the space they need to expand and properly steep.

3. Measure out the right water to tea ratio

Tea bags are generally made for 8 oz of water, which is about the amount of liquid a teacup holds. Mugs have a larger capacity of 12 oz or more, so be mindful about not topping off your mug with water, which might result in a watered down brew.

For loose leaf tea, use a teaspoon of tea leaves per 8 oz of water.

Ultimately, most tea packaging will have a suggestion for your tea to water ratio.

4. Heat water to the temperature for each tea type

Each type of tea is processed differently, resulting in a slightly different method required to properly steep each one. The right water temperature extracts the right amount of aroma, tannins (affects the bitter taste), antioxidants, and amino acids [4].

Black: 195 - 212°F (90 - 100°C). Water should reach a full boil.
Oolong: 180 - 185°F (82 - 85°C) for lighter oolongs and close to boiling for darker oolongs.
Green: 160 - 185°F (71 - 85°C). Let water cool for a few minutes right after it has almost reached a boil.
White: 185 - 200°F (85 - 93°C). Similar to green tea.

5. Steep for the appropriate amount of time

Steep time is the final crucial step to make the scientifically best cup of tea.

The time you leave your tea leaves in the water affects the caffeine concentration, bitterness, and boldness of flavor [5] [6]. A study found that almost all the antioxidants are extracted within the first 5 minutes of steeping [7]. For a stronger steep, just use more tea leaves rather than increasing the steep time, which can make tea bitter.

I once saw a woman at the breakfast buffet of a hotel dunk her tea bag in water a few times only to then immediately dispose of it once her water turned colors and walked away (to my horror) satisfied with the non-tea, watery substance she created.

Here’s the suggested time for how long to steep each tea type [8]:

Black: 2-5 minutes (depends on cut of leaf)
Oolong: 1-5 minutes (depends on the style)
Green: 2 minutes
White: 2 minutes

Again, when in doubt on how long to steep tea, the tea’s packaging or brand website is likely to have more precise instructions on steeptime.

Other random questions about making tea

For all the other little details about making tea properly:

I’ll admit to having made tea in the microwave in an act of desperation, but should the microwave be a go-to source for heating up water?
The answer is no if you can avoid it for two main reasons.
First, microwaves heat food unevenly, meaning they create pockets of cold and warm, although this is less so with water and cylindrical containers like a mug that allow the heat to travel around more easily [9].
Second, heating water for tea in a microwave makes it impossible to control how hot the water gets. Because water temperature is an instrumental step to making the perfect cup of tea, the microwave method isn’t ideal.
Teapots with a strainer or steeper are suited for loose leaf teas, as the mesh prevents the tea leaves from pouring out with the brew. Some teapots have a separate, removable strainer chamber, while others have a mesh behind the spout, giving tea leaves the ability to swish around the whole teapot.
Keep the right tea to water ratio in mind so you don’t end up with a watered down pot.
Of course, you can also use tea bags with any teapot.
Boiling water more than once drives oxygen out, which can make tea smell and taste flat [10]. While the tea will technically steep fine with twice boiled water, the taste likely won’t be the same and it won’t be as aromatic [4].
Boil water on the stove if you don’t have a kettle. You can then add your tea to the pot to steep or pour the water into a teapot or cup. Several types of tea around the world are also prepared directly on the stove like chai, with spices and milk added into the pot.
Yes! Cold brewing tea is super easy and maximizes the taste and nutrients extracted. And because you’re not dealing with hot water, there is no risk of your tea over-steeping and turning bitter.
Using a larger quantity of a bold loose leaf tea like Assam and a saucer on the stovetop is the way to go if you want to skip the water and steep straight in milk. If loose leaf isn’t an option, you can double up on tea bags and cut them open into the milk. In fact, traditional Indian chai is sometimes brewed in milk or even a combination of milk and water.
When adding milk to tea steeped in water, just a splash is standard to maintain the subtle flavors and strength of the tea [11].

[1] Cartagenas, Ivy. “Keeping Your Warm Drink Warm - a Thermal Properties Approach.” Thermtest, 3 Feb. 2022, https://thermtest.com/keeping-your-warm-drinks-warm-a-thermal-properties-approach.
[2] Spence, Charles, and Fabiana M. Carvalho. “Assessing the Influence of the Coffee Cup on the Multisensory Tasting Experience.” Food Quality and Preference, vol. 75, 2019, pp. 239–248., https://doi.org/10.1016/j.foodqual.2019.03.005.
[3] Giacomin, Caroline E., and Peter Fischer. “Black Tea Interfacial Rheology and Calcium Carbonate.” Physics of Fluids, vol. 33, no. 9, 2021, p. 092105., https://doi.org/10.1063/5.0059760.
[4] Keating, Brian, and Long, Kim. How to Make Tea: The Science Behind the Leaf. United States, ABRAMS, Incorporated (Ignition), 2015.
[5] Chin, J. M., et al. “Caffeine Content of Brewed Teas.” Journal of Analytical Toxicology, vol. 32, no. 8, 2008, pp. 702–704., https://doi.org/10.1093/jat/32.8.702.
[6] Matthews, Carolyn M. “Steep Your Genes in Health: Drink Tea.” Baylor University Medical Center Proceedings, vol. 23, no. 2, 2010, pp. 142–144., https://doi.org/10.1080/08998280.2010.11928604.
[7] McAlpine, Michael, and Wendy Ward. “Influence of Steep Time on Polyphenol Content and Antioxidant Capacity of Black, Green, Rooibos, and Herbal Teas.” Beverages, vol. 2, no. 3, 2016, p. 17., https://doi.org/10.3390/beverages2030017.
[8] Heiss, Mary Lou, and Heiss, Robert J.. The Tea Enthusiast's Handbook: A Guide to the World's Best Teas. United States, Clarkson Potter/Ten Speed, 2012.
[9] Hossan, Mohammad Robiul, et al. “Analysis of Microwave Heating for Cylindrical Shaped Objects.” International Journal of Heat and Mass Transfer, vol. 53, no. 23-24, 2010, pp. 5129–5138., https://doi.org/10.1016/j.ijheatmasstransfer.2010.07.051.
[10] “Should One Worry about Reboiling Water for Coffee or Tea?” Office for Science and Society, 23 Mar. 2017, https://www.mcgill.ca/oss/article/controversial-science-health-quackery/should-one-worry-about-reboiling-water-coffee-or-tea.
[11] Knight, Robert. “Tea Drinkers Add 5ml of Milk on Average, Says Study.” The Independent, Independent Digital News and Media, 23 Apr. 2018, https://www.independent.co.uk/life-style/national-tea-day-drinkers-milk-splash-definition-cup-average-5ml-poll-results-a8314676.html.
[12] BBC, director. YouTube, YouTube, 14 Jan. 2019, https://www.youtube.com/watch?v=Fhuc6qOGNPc. Accessed 24 Nov. 2022.

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about the author

Hello, is it tea you’re looking for? Raquel is an Arizona-based tea drinker who writes about tea as a side hobby. Her current favorites are Earl Grey with a splash of milk and any Japanese green tea.