The Tea Curious Blog

5 Reasons To Test The Water You Use To Brew Tea


Electric kettle next to a few different brands of bottled water

Have you ever found an amazing tea at a tea shop, only to find out that it tastes suspiciously different at home?

Or have you ever found that your tea has none of the fancy flavor notes on the vendor's website, making you wonder if you're just not a good taster?

Uhhh, I sure have! And for a long time I blamed myself (for not brewing or tasting things right), my teaware setup, or I blamed the tea. Like, maybe the vendor was overselling the tea a bit or something, or I just wasn't into that specific kind of Chinese white or whatever.

But there's no need to blame any of that, because there's something even more fundamental that might be going haywire.

Y'know, the thing that makes up 98% of a cup of tea. 


lineup of bottled waters

For some reason, water is the elephant in the room we almost never talk about in tea.

I get it. We don't wanna look like stuck-up snobs, ooh-ing and aah-ing about the merits of meltwater from the Swiss Alps versus Icelandic glacial water. But in truth, water isn't just a pretentious extra to the tea making process: it's the foundation of good tea, more than any traditional tea pot or fancy brewing technique.

So if you're already testing different types of teas and tea accessories, you should definitely add water to that list. Here's why.

#1: Certain waters make tea look AND taste different.

Sure, different teas definitely have different flavors and appearances. But beyond the type of tea you're using, your specific water could be changing things up, too.

Depending on what kind of water you're using, you could be experiencing more bright, aromatic and flowery notes, or more deep, kinda bassy and earthy flavors. And in some cases, certain waters can mute the tea altogether, making the tea seem tasteless or flat!

And while I'm still waiting for Flavor-Vision to be invented so that you can taste the proof through the Internet, I can at least show you that there's a difference.

brewed tea using different waters, varying colors

Here's a picture from an experiment I did with the same green tea, brewed with 8 different bottled waters. I prepared it the exact same way: same amount of water, same time, same temperature.

YO. Can you believe the color differences here? This green tea looks like two different teas here: but I swear it's the same tea. All that's different is the water: and with such a big change in color, you bet the flavor, aroma, and texture changed a loooooooot, too.  

Check out the full results in my experiment, “Comparing 8 Bottled Water Brands for Green Tea”.

Out of the 8 brands of water I tested with the green tea, I liked just two: a 20% success rate from that selection. And of the rest, 4 of them did terrible things to that poor tea, which means it was basically a 50/50 chance that the water screwed up the tea royally.

This doesn't apply to just green teas, either. It matters for all teas. Check out another experiment I did with a black tea brewed with three different kinds of water (and spot the color differences again!).

The same tea made using three different waters, varying colors

The same Assam black tea with three different waters: Aquafina, Arrowhead, and tap water.

SERIOUSLY, doesn't it look like a different tea in the first cup?

But again, I brewed this tea in the exact same way each time, keeping all the ratios and times and temperatures the same: except for the water. In this case I used Aquafina, Arrowhead, and tap water, and it was the Arrowhead that came on top, making the tea taste wonderfully bold and malty!

As for the other two? The Aquafina made it taste tinny and weak, while the tap water made it taste like old pool water. Yum...

I've been doing these tests for years now, but the results shock me every time. It's like drinking three completely different teas. And when you do these tests, you'll be shocked by how often you find waters that just completely kill the tea while others just take the tea to the next freakin' level!

#2: You may be able to fix your stubborn tea stains.

So for a long time, I was dealing with super tough stains on all my teaware.

No matter how diligent I was at cleaning out the tea immediately after drinking, I'd get ugly brown spots on the rims and insides of all my teaware. Eugh.

I figured this was a #JustTeaThings problem, but in reality, it had less to do with my all-day tea habit and more to do with the water.

Check this picture out, from the black tea experiment from earlier:

Two cups of the same tea made with different waters. Left, no stains. Right, stains.

Remember, I used the same tea and brewing method, but with different waters: so then why is one stained, and the other squeaky clean? It's because of the water!

These oily, grungy stains kinda look like dirt, but they're actually caused by water with high calcium content. Calcium can bind to tea tannins, which are found in high quantities in black tea and certain oolongs. Having one or the other is OK, but when there's an excess of both we get these stubborn af stains.

Basically, super hard water + tannin-heavy teas = tea stain city.

And if these tea stains are commonplace for you, you may have also noticed that your water leaves chalky residues on just about everything, including your dinnerware, windows, car... and most horrifyingly, your tea kettle.

Y'know that weird build up in your kettle that's REALLY hard to scrub off?

Yup! That's another water issue too, and totally preventable. Water scaling in kettles goes away completely with the right water, usually a lighter, softer one with fewer minerals.

The good news is that many of the best waters for tea are naturally soft, without the excess calcium that causes these stains and chalky residues. So you get amazing tea AND keep your tea stuff super clean. It's a win-win all around when you find the right water.

#3: You won't know how your water measures up until you test it. (Yes, even if it SEEMS good!)

When I first started posting my water experiments on Instagram, I received some confused messages from tea friends from some truly H2O-blessed countries: places like Canada, Finland, Sweden, Germany. 

“I didn’t know that water mattered so much for tea!” they said.

Also, “Did you know that in Finland, our tap water is better than the local bottled water?”

Cue some serious natural resource jealousy!

It's absolutely true though: some places just have better water than others. And yes, you may already have the perfect water for brewing tea, but the thing is, you won't know just HOW good your water is until you test it side-by-side with something else.

I personally didn't even have a clue there was something wrong with my water for years. I figured I had a nice Brita filter that I studiously changed out whenever the filter light came on -- no problem, right? I cringe thinking about all the nice, expensive tea I didn't get to fully enjoy for all those years.

Sometimes, you just don't know until you try something better.

And even if you have some extra virgin glacial meltwater coming straight out of the faucet, I still recommend testing it side by side with a few bottled water brands to see exactly how it stacks up.

Also, try comparing your water home with somewhere else in town, like your work or a friend's house. Thanks to things like old pipes and different groundwater sources, areas within the same city can get vastly different water quality: you may have noticed that your tea brews up different at home than at the office!

Finally, many waters that we love for drinking don't perform well for tea. Waters like Evian, Acqua Panna, and many other fashionable spring waters may taste great, but the same minerals that make them so tasty also perform pretty poorly when brewing tea.

Don't assume that amazing tasting water equals amazing tea brewing water. The only way to find out is to test, test, test!

So go see how your water stacks up, yeah? Brew it side-by-side with other waters, using a tea you know well. Then, mix it up and test a few other tea types as well, since certain waters do better for certain teas. You may find that your water does well with white tea but just OK for pu'erh.

And if you do find that your water really is the best water in the world... well, do me a favor and drop me a sample in the mail, will ya? ;)

#4: Traditional tea wisdom talks a LOT about water, too.

If all this water talk from me doesn't have you convinced, then I'm gonna have to name drop for a sec. ;)

You may have heard of Lu Yu - known as China's Tea Sage, author of the Classic of Tea (Cha Jing) which was published around 730 AD. He's basically the first tea nerd known to history, and he was also into finding good water for tea brewing.

Like, really into it.

In the Classic of Tea, Lu Yu covers tea preparation, tea tools, and tea culture in-depth over 10 chapters. The book demonstrates just how sophisticated tea culture was even back then, but also how choosy they were about water. A whole section of the book is dedicated to the methods for choosing, storing, and brewing water.

Which means this study for water for tea has been around for at least 1,200 years!

Lu Yu writes that water from mountain springs is the best, followed by river water. Then there's well water, also known as groundwater, which is considered to be pretty subpar. There's variation within those categories of course, but it's pretty interesting that his advice holds up well today: most groundwater does pretty poorly for tea.

A story from another work, Record of Water For Brewing Tea (825 AD), claims that Lu Yu was so keen about water that he could tell you a water's exact origin just by taste! He could even tell whether the water was drawn from the best area of the source, for example the center of the river versus the river banks.

Record of Water for Brewing Tea goes on to list Lu Yu's 20 favorite sources of water scattered across China, allegedly compiled during his travels. It's a super specific list with names such as "the pond below Zhaoxian Temple in Lushan" and "Qianzhang Waterfall in the southwest peak of Tiantai Mountain".

Guy was hardcore, man.

Above is a picture of Lu Yu's second favorite water out of the 20: Huishan Temple's spring water, located in Jiangsu, China. It's crazy that Lu Yu's water studies were done more than 1,200 years ago, but today the spring is still called Tian Xia Di Er Quan, or "The Second Best Spring Under Heaven".

For our tea brewing ancestors, good water really was inseparable from good tea. This concept is explored again and again throughout Chinese tea history, and then later in Korean and Japanese tea history as well - and today, we're lucky to have many more tools and water types at our disposal, too. Let's continue what our ancient tea friends taught us and take water seriously for tea!

#5: The right water can give you incredible amounts of control over your tea.

So if you've made it this far, you're probably pretty convinced about all this water stuff, but also still a little on the fence.

Like, it makes a lot of sense that there are different kinds of water and that some could do better than others with tea.

But is it REALLY worth the effort to fiddle around with water and do fancy side-by-sides? Like a water sommelier, or something? Maybe this water stuff is meant for ancient teamasters to do with their free time, not just "regular" tea folks like us...

notes with the lineup of waters being tested

But the thing is, if you're already testing things like brewing tools and teas, it's 10000% worth it to test your water.

Because here's what I think.More than fancy teapots, tea cups, and high grade teas...

Good water is the single most important thing you need to make good tea.

And while it's true that it takes time and effort to work on your water, it's totally worth it because good water upgrades every single tea in your collection. Think about it: even the best, most authentic Yixing clay pot (which can cost $$$) or Tokoname clay kyusu will end up improving just one or two types of tea. Good water improves ALL of it.

With the right water...

  • You get the maximum flavor, aroma, texture, and aftertaste from every tea.
  • You create a tea setup you can rely on, so you know you won't mess up precious teas!
  • You'll be aware of when water is affecting a tea session, even when you're away from home (you'll know exactly why your favorite tea isn't coming out right at your friends place - it's their gosh darn fridge water!)

And dude, when you use good water to brew tea THEN go back to the old stuff... you'll be shocked.

You'll be amazed by the difference, I promise.

So go ahead and test your water! It's as simple as picking up a few bottled water brands from the store and seeing how they do compared to your current water. Brew up your favorite tea with different waters, then test them side by side so you can get a clear read on the results.

Bonus points for testing local spring waters as well, or making use of our Tea Curious water formula. Seriously, I only wish I'd known sooner myself!

A picture of the author

About the Author

Hey there, I'm Rie and I'm a professional tea nerd. I share the techniques and strategies we've used to seriously level up our tea game so you can get super confident with tea too!