Tea and Water – Does Water Quality Alter the Taste of Brewed Tea? Part 2

Tea and Water – Does Water Quality Alter The Taste Of Brewed Tea? Part 2 – Iced Tea

Apparently, it does.

Last week, we experimented brewing hot tea with different types of water (tap, filtered, Mt Franklin and Evian) to see if they created a difference in taste, results found here: The resulting brews were quite surprising in their individual characteristics, with some unexpected insights revealed about which water source produced the best outcome when making a hot cup of tea.

Today, we take on a different approach to traditional brewing by making iced tea using the cold-brew method.

To cold-brew a tea is as simple as tossing a teabag in some cold water and leaving it in the fridge overnight. The benefit of brewing iced tea this way, is that the slower extraction process brings out the more delicate subtleties of the tea leaf. And as a much lower temperature is used, fewer tannins are extracted, resulting in virtually no bitterness to speak of. Scientific studies have also shown that tea brewed in cold water for 12 hours contain more polyphenol antioxidants than tea brewed in hot water for five minutes, making this a very healthy option for summertime refreshment.

So we’ve sliced up some fruit, thrown in a teabag, added nothing else but water, and what we are left with in the morning is a beautifully flavoursome iced tea, completely natural in sweetness and fuss-free.

Once again, curiosity got the better of us, and in the search for the most delicious taste sensation possible, we decided this time to explore how different kinds of water alter the taste of iced tea.

The Water

Sydney Tap Water: high quality, easily accessible, convenient, contains natural minerals and additives like fluorine, environmentally friendly, $0.0022/litre

Filtered (Clean Water Products P/L): experts in filtration, removes many sediments and impurities from tap water, usually a ‘cleaner’ and more refreshing taste, requires ongoing investment

Mt. Franklin: most popular bottled water in Australia. It might be worthy to note that Mt Franklin water does not actually come from a mountain, but is purely from various Australian springs. Relatively neutral in pH and balanced in mineral content. $2/litre

Evian: sourced from the French Alps, filtered through mineral aquifer for 15 years within the mountains before emerging at the spring in Evian-Les-Bains. Balanced mineral composition, $4/litre

The Tea

Pear and Jasmine Iced Tea – using our exclusive Buddha’s Brew, a naturally fruity and floral Jasmine green tea, with fresh sliced pears. One pyramid and half a pear per 200ml, brewed with cold water for twelve hours in the refridgerator.

Peach Black Tea – using Altitude Tea’s English Breakfast blend, a naturally sweet black tea, with the addition of fresh sliced peaches. One pyramid and one third of a peach per 200ml, brewed with cold water for twelve hours in the refridgerator.


Again, the flavour profile remained consistently excellent throughout all eight trials, with less discernible variations between them than those from our hot tea experiment. The colouring of all eight glasses of iced tea were consistent in brightness and depth after twelve hours, but the Altitude Team still managed to spot a few differences in taste and aroma.

Both the green and black iced teas made with tap water produced a lightly fragrant cup, delicious and perfectly good for cold-brew tea. These cups brought out a slight tartness from the fruit, a tang which some participants found enjoyable. Perhaps a noteworthy opinion was that using tap water meant that to maintain the freshest taste possible, one has to consume the iced tea as soon as the brew is ready. This may be due to the various additives and impurities which may render tap water less likely to keep fresh in refrigerated storage for a prolonged period of time.

In stark contrast to our hot tea experiment, filtered water produced the most brilliant results of the four. The scent of this iced tea was the most aromatic and fresh, like the crisp wind that blows through the fruit orchard on a cold winter’s morning. We felt like filtered water achieved the purest taste and the simplicity of flavours presented, combined with a very clean finish, produced the most refreshing glass of the day.

It is hard to go wrong with our expert selection of tea no matter how you brew them, for the quality behind the leaves means they are likely to taste wonderful nonetheless. The iced tea brewed with Mt. Franklin was no exception, but we did find it made for a less rounded taste, slightly flatter than the rest, but satisfyingly smooth.

Again as a close contender was the bottled water Evian. Flavour from the fruit and tea leaves were very efficiently extracted, resulting in a concentrated brew which was heavier in structure. Highly enjoyable by all, but ranked lower in terms of refreshing qualities due to the strong nature of the flavours presented.

If we were to rank our four choices, these are our impressions, with the top three being relatively close in reviews:

  1. Filtered
  2. Evian
  3. Tap
  4. Franklin


It appears reasonable to the Altitude Team that filtered water made it to the top of the list, with the reduction in minerals and sediments being conducive to the cleaner and more refreshing taste that we preferred in an iced tea. Filtered water imparted a purer flavour from both the leaf and the fruit; a refined interpretation. For this reason, we use filtered water in every bottle of Altitude-made cold-brew.

Again, Evian comes second; fantastic for the extraction of flavour due to its balanced mineral composition and undoubtedly premium in quality for its mountaintop origins. A slightly heavier beverage meant this was less refreshing than filtered, but we were impressed at the level of concentration obtained from the leaves.

Tap water made for a delicious and convenient glass of iced tea, flavoursome as the options above and with more tasting notes detected than in the other types of water. As we said, it’s a close call but we have chosen to rank it slightly lower for its decreased ability to remain fresh in storage in comparison to filtered and bottled water.

We enjoyed the smooth characteristics of Mt Franklin, but as bottled water in general comes as a cost to the environment, and this particular brand did not especially enhance the taste of the tea, we have ranked these cups as last on our list.

Another productive experiment from the Altitude Team and we hope you have enjoyed reading our findings. Let us know how your cold brew adventures go!