Before we get started I don't want you to believe that you can not make a respectable cup of tea in Brisbane. In the arena of taste there is a level of subjectivity that is unique to each individual. I personally have had some of the most satisfying brews as well as some of the most disappointing in this city.
It has taken me a little while to stop the denial about the impact of the local tap water in the tea making process. After adjustments to brewing parameters and a really interesting experience bringing samples back from Japan and experiencing them completely differently (negatively) in Brisbane it has spurred my curious mind to get some answers.
The reason water is so important in tea making is because it makes up around 99% of the infused tea liquor with the remaining 1% comprising the soluble tea components.
In order to understand why Brisbane's tap water may not suit the brewing of all tea types let's take a deeper look.
Our bulk water is supplied utilising the SEQ Water Grid that is made up of a series of water catchment areas and water treatment plants. Each catchment area has a water profile and treatment process that creates a unique taste to the water. Depending on supply and demand, the network will direct the water to different areas of the grid resulting in consistent changes in the water that is being drawn from our taps.
Brisbane's bulk water supply is described as hard. Hard water is high in naturally occurring dissolved minerals, specifically calcium and magnesium carbonates (chalk).
In 2017/18 the total dissolved solids (TDS) for SEQ Water Supply (including Brisbane and Ipswich) was reported as 290 mg/L. Compare this to Richmond in Melbourne that comes under the City West Water supplier who reported a TDS of 22mg/L. You can see that Melbourne's water supply is lower in TDS than Brisbane. In this range the water can be described as soft. And I hear few complaints about water from my Melbourne tea colleagues.
Before getting too excited that this single digit scale offers the answer as to what the water will taste like it is important to realise that this number does not describe the actual mix of the minerals dissolved in the water. It is this mix (as well as some other key information including pH) that start to give us clues as to how tea might be experienced. Those chemicals most plentiful in water are calcium & magnesium, carbonate and bicarbonate and form the basis of most of the discussions around water and taste in my preceding posts. To round out the picture Brisbane's total hardness (calcium and magnesium) is 120mg/L and pH 7.7.
The Experiment
In the first really basic experiment I cupped 3 samples of Arakai Estate's 2018/19 black teas using the following parameters. Out of curiosity I asked Arakai Estate what water they use to evaluate their teas and they told me they used rain water (which can be categorised as soft water).
Water: 150mL of either carbon filtered water (my home set-up with the hard tap water) or Mount Franklin (the water used by my Japanese tea friend for green tea making and what I had available in the realm of soft water). Going forward I will measure the water as best I can prior to brewing and share this with you.
Tea: 3G
Infusion time: 5 minutes
In the image below. The top cupping line has been brewed using Mount Franklin water and the bottom line with carbon filtered tap water.
The colour of the tea liquor is the first noticeable difference between the water sources. The tap water has brewed what looks like a lighter infusion compared to the bottled water.
The aroma of the tea liquor and infused leaves was also very different. The soft water revealed more complexity in aroma profile with very distinct floral notes whilst the tap water muted these.
There was also a difference in the flavour of these teas. Those brewed with tap water had a good mouthfeel, a rounded and balanced infusion that had floral notes and a semi-sweet finish. Those brewed with the bottled water were more complex with more distinguished floral notes that I think I would definitely prefer to gong fu cha. These teas are very recent harvest black teas and I found the tap water drew out more of the fresh green profile of the tea.
Conclusion:
In this experiment the aroma and flavour that was brought out by the bottled water was more bright and complex and was preferred to the tap water. The tap water tasted a little under-extracted with the flavours particularly the floral notes being softer. I would say the mouthfeel was similar in both waters and both were drinkable brews.
The most enjoyable brew was the third tea in the cupping line and I didn't waste either of the infusions.
Tune in next week for more tea for water fun!
