I’ve procrastinated writing this due to the sheer amount of information I have to post. Water was a topic I did quite a bit of studying of back in 2016. If my information came from the web, its likely from tea blogs I was visiting at the time. If you are reading this and really want a source, I will search for them diligently. If it came from books it would have been Fine Waters by Michael Mascha or Water: A Comprehensive Guide for Brewers by John Palmer and Colin Kaminski. Other books are quoted when relevant because I’ve taken maybe 1 sentence from them.
Water Chemistry and its effects on Flavor:
pH is measured on a scale of 0 to 14 with 7 being neutral. Values less than 7 are increasingly acidic while values greater than 7 are increasingly basic. pH is a logarithmic scale, the difference of 1 indicates a 10 fold increase or decrease in acidity or alkalinity. Water with a pH of 5 for example is 10 times more acidic than that with a pH of 6.
Acidic pH 5~6.7
Neutral pH 6.7~7.3
Hint of Sweet pH 7.3~7.8
Alkaline pH 7.8~10
High pH water (alkaline) will create a tea infusion that looks darker brown due to the greater ionisation of the polyphenols found in tea. Lower pH water (acidic) will turn water yellower.
Water has buffers in place which cause it to resist changes in pH when another chemical is added (Salt, Sugar, Acids, Bases.) The primary buffer in water is usually its Alkalinity.
“Boiling has been used for hundreds of years to reduce alkalinity and hardness of water. Broadly the way that it works is that the rise in temperature changes the state of saturation of all the carbonate species in a solution.
First the carbon dioxide evolves from the water due to the rise in temperature. The removal of carbon dioxide unbalances the equilibrium between the bicarbonate and carbonic. This causes bicarbonate ions to convert to carbonic acid and aqueous carbon dioxide, and in doing so consumes protons thus raising the pH. The increased pH causes some of the remaining bicarbonate ions to convert to carbonate ions. This results in saturation with respect to calcium carbonate which precipitates.
The calcium carbonate which precipitates exists as micro crystals in suspension which will eventually grow heavy enough to settle at the bottom of the water. Historical brewing texts for beer wrote water would typically be boiled for 30 minutes to scrub away the carbon dioxide. It would be allowed to settle overnight. The water would be decanted off the sediment and used as brewing liquor which would have reduced alkalinity.”
It should be noted that because boiling water reduces alkalinity (increases acidity), reboiled water can brew tea of a different color and strength. According to our friends in India at the Tea Research Association in Kolkata reboiled water is not suitable to brew a good cup of tea.
Removal of carbon dioxide effectively removes acid, which increases the pH, and a high pH favors the conversion of bicarbonate to carbonate. During this process calcium is also lost which is not necessarily favorable. It can be replenished with calcium chloride or sulfate.
At this point, reading through my old notes is confusing me and I’d need to speak with someone verbally to help me understand it. Boiling water increases acidity by reducing alkalinity. Just now I’ve said removal of carbon dioxide (which boiling does) removes acid which would raise alkalinity? I don’t know, man. Science.
To get rid of the temporary hardness of water it must be boiled for no less than 20 minutes. Note that temporary hardness means calcium carbonate and calcium bicarbonate. Magnesium content is a major component of how water is perceived as ‘hard’ — it’s the combination between magnesium and calcium which determine a waters ‘hardness’.
Low alkaline waters (ph 7.1~7.5) may be percieved as sweet. Not that the water tastes sugary, but simply that it tastes neither bitter nor sour. Alkaline substances tend to taste bitter and may seem to have a slippery feel. Acidic substances taste sour.
Be sure not to let pH have too much influence when considering the flavor of water. In the 5~10 range the pH factor plays a minor role (5% of the flavor) relative to the total dissolved solids (20%) and the carbonation (75%) In the realm of tea preparation the ideal water is pH neutral and low TDS (especially calcium/magnesium)
Regarding water chemistry in the scope of Coffee: (excerpt from Everything but Espresso by Scott Rao)
Too Low TDS results in unrefined flavors, little mouthfeel
Too High TDS results in dull, muddled flavors
Too Low (Acidic) pH results in brighter and more acidic flavors
Too High (Alkaline) pH results in dull flavors
Too Low Hardness results in thin coffee which lacks structure
Too High Hardness results in chalky tasting coffee
Regarding water chemistry in the score of Sake: (excerpt from The Sake Handbook)
The most famous example of good brewing water is that which comes gushing up in the Nada region of the city Kobe in Hyogo prefecture after filtering slowly down through a nearby mountain, Mt. Rokko. It is known as ‘Miyamizu’ and has an ideal mineral content for sake brewing. This has made the Nada region the top brewing region in the country, in terms of volume. When brewing sake there are a number of elements whose presence is indispensable, as well as some which are only detrimental.
By far the most detrimental element is iron. Iron will darken the sake and and adversely affect its taste and fragrance. This happens because it chemically attaches itself to the center of a normally colorless and odorless compound which is in itself attached to an amino acid produced while the koji is being made. Also as sake ages the residual sugars react with amino acids that are present which changes the flavor and aroma, in the presence of iron this process is hastened.
Manganese plays a different but equally despicable role. When sake is exposed to UV light manganese promotes a chemical reaction that will discolor and dull the appearance of sake. In direct sunlight a noticable change will occur in less than 3 hours.
Beneficial elements are potassium, magnesium, and phosphoric acid.
Hard water allows a more vigorous fermentation to happen and leads to a clean, solid sake. Soft water helps bring about a sake which melts onto the palate.
Sourcing Water:
Traditionally spring water that was collected for tea has maintained a connection to the earth it was drawn from. The longer this connection with the earth is maintained the more fresh the tea will be.
Breath-ability is important when you are storing water. The water must be able to breathe or else it will not maintain its vibrancy and will no longer be suitable for tea. This is especially true if the water will sit for a long time. If it cannot breathe the water will suffocate, its Qi will be depleted. Water in nature breathes and so should it in storage. As water sits it becomes stagnant and its Qi scatters. It is very important that water used for tea is either stored properly or only for a short while. Waters connection with the earth (a ceramic jar in my case) will ensure the Qi is maintained and is enhanced by the minerals in the clay influencing the water.
Rain is the origin of all water (if a cycle can have an origin.) When winter snowfall in the alpine regions melts during Spring, it flows into rivers and into the underground water table. Rain Water and Snow Melt is young with an extra low mineral content. Typically pH is around 7.1~7.8 and the TDS is between 5mg/l and 91mg/l. In a ‘mystical’ point of view water from a mountain peak is pure and light, and the higher in elevation water is found the more yang energy it has. It is thought to have this energy because it had to have traveled from a source so low to a place so high. It is thought to be pure because it is closer to heaven. It’s also less likely to be contaminated by things flowing down stream.
Deep circulating water often has a high mineral content because it interacts with rocks for longer periods of time. Water from a spring at the foot of a mountain is pure but heavy. It is still pure because it came from a mountain and has not been contaminated by things flowing down stream. It is considered heavy because it doesn’t have the ability to climb. It is weighed down and flows from the mountain at a low altitude. It is more likely to contain minerals and salts. This type of water has strong, pure yin energy.
At the end of my pile of papers there are several proverbs. I’ll end with these.
“Water emerging amidst the rocks is pure and sweet. Earth tastes sweet and rocks are considered the truest earth. Yang.”
“Water emerging from sand is pure and cold. Yin.”
“Water emerging from soil is bland and plain. It has no essence. Soil leaches out the waters minerals.”
“Water flowing from yellow rocks is good. Yellow is the color of the earth. Yellow rocks indicate the water that has the most harmony with the earth.”
“Water draining from dark rocks cannot be used. Black or even dark blue is the most yin color. The water contains too much yin energy and will not be active enough to bring out the essence of the tea.”
“Flowing water is better than still water.”
“Water emerging from a shady place is better than a sunny place. Sun causes the water to accumulate algae/life therefore water should not be exposed to light.”
When preparing tea: “the most suitable water is from the same region as the tea” – Lu Yu
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