Following on from the previous article, let’s continue talking about the extremely large and complicated topic that is water and tea brewing.

After all, water is important for the taste of your tea. And the most effective thing you can do to improve your tea, short of getting better tea, is to improve your water.

What water is right for making tea?

Firstly, the results of a simple experiment.

look around you

I made several batches of water from scratch by adding magnesium sulfate (epsom salts) and sodium bicarbonate (bicarbonate/baking soda) to distilled water. I made two concentrates in separate bottles, and then titrated these concentrates into distilled water with the equation of 1000g DI water - weight in grams of concentrates added. The concentrates are made such that 1g of concentrate = 1mg/L of either the magnesium or bicarbonates. I will detail exactly how to make your own water at the end of this post.

I then tested brewing tea with each batch, with the goal of graphing the small changes in buffer and hardness against changes in taste. The same tea, ratio, teaware, brewing times, and temperature was used throughout. The only changed variable was the amount of buffer and magnesium in the water itself. The kettle was thoroughly rinsed with distilled before the new water was added to minimise mixing of different waters.

The tea was assessed informally for sweetness, body, and presence of any off flavours. At this time I don’t have the resources to do a better quality experiment, but I plan to do one in the future, using around 8 different kettles and sets of brewing tea, and tasting them side by side, blind with multiple participants. Stay tuned!

However, this experiment still proved interesting. It added evidence to some previously held theorising, and made me re-appreciate just how complex water chemistry is.

RESULTS

tea brewed for the same time with distilled (left) and hard water (right)

In the sweet spot, there was a balance of the thickness of the infusion, no faulty aftertastes, proper expression of astringency and bitterness, and most noticeably, the best amount of sweetness (including huigan).

On the graph, there is two zones. The light red is an approximation of a range where you should get maximum sweetness and a clean tea with good clarity of flavours. The dark red zone is where there is more body, and a little less sweetness depending on the tea, but there is no negative flavours from the water.

MAKING YOUR OWN WATER

Taken straight from Barista Hustle, here's how to make your own water.

Ingredients:

Baking Soda - NaHCO3, Sodium Bicarbonate, Bicarb (not baking powder)

Epsom Salts - MgSO4, Magnesium Sulfate, Epsom Salts

Deionised/Distilled/Ultra-pure water 

You should be able to buy these ingredients at the supermarket for little cost.

Equipment:

Scales (accurate to 0.01g)

3 x ~1L water containers (preferably glass, and odour/residue free)

Method:

• Dissolve 1.38g baking soda in 1L of deionised water — this is your “buffer” concentrate, or “alkalinity”. Label and set aside.
• Dissolve 10.14g Epsom salts in another 1L of deionised water — this is your “Magnesium” concentrate, or “total hardness”. Label and set aside.

Now that we have the two concentrates, we can start building our own water from distilled.

From my earlier experimentation, this seems to be a good starting point for most teas, and will give a clean, clear, tea with good expression of flavours and sweetness, but not too much body.

7g Buffer
2.8g Mg
990.2g Distilled water

For heavier teas or if you prefer a bit more body/punch at the cost of some sweetness and crispness, we nearly double the previous recipe:

12g Buffer
5g Mg
983g Distilled water

The table below shows all the waters I tested and the amounts of buffer and magnesium for each.

It seems like a small difference in terms of mg/L, but it makes a noticeable difference. Of course, again, caveat: these are based of my simple, very non-scientific experimentation, and are based on my particular tastes and biases and the tea I used. Your preference might be vastly different, so experiment heavily and find out!

Represented as a (very) rough compass of flavours vs concentration of each:

The beauty of making your own water this way, is that you can directly control the flavours, and that you can be almost perfectly consistent. Even buying spring water from some companies or especially locally can vary significantly depending on rainfall and other factors, between batches.

Other advantages are that this water is cheap to make relative to buying spring water. Making the salt and buffer solutions is quite easy and cheap, and making a 1L batch of each will last a long time for making tea water.

FINAL WORDS

Again, my greater point with these two articles is to stress the importance of water on the taste of your brewed tea. At the very least I would strongly encourage you to try different waters that are available to you for brewing tea; don’t just assume that the water you currently use is the best water. If you’ve used it for a while, you will have adjusted to the flavours and they will be what you think of as ‘good’. But if you try out some different waters, you might find a whole bunch of flavours you didn’t think were possible before. If your tea tastes better, then you’ve just found the easiest thing you can do to improve your sessions! Fantastic!

Play around with different water recipes to see what works for you, and just as importantly, what doesn’t. I think it’s a good idea to see the total range of water does and doesn’t do to the taste of your tea. This may help you in situations where you have unfamiliar water, or when brewing tea and it doesn’t quite taste as it should, or when assessing tea brewed by someone else or in an unfamiliar place. A tea that tastes bad in a shop might actually be a great tea underneath that subpar water. If you familiarise yourself with the general tastes associated with extremes of water, you’ll be better prepared for these situations.

Water chemistry is decidedly more complex than the DIY method here can hope to COMPLETELY explore, but for practical purposes I think this is a great way to get started. If was a scientist and had access to mass spectroscopy and chromatography and other such methods, it would be interesting to see this experiment with water make up repeated and related directly to total extraction of tea compounds.

Heavily drawing upon the book Water for Coffee, as well as the DIY water recipe approach from Barista Hustle.

Have a play around yourself and see how you go.

Enjoy your tea!