To boil or not to boil

[Jayaratna]

Dear all,

recently several topics here are concerned, directly or not, with water quality and how tea is affected by different water and different tools/method for boiling it.

This led me to consider that, being mostly a green tea drinker, I never truly boil my water. I have always heard that water should not be boiling for green teas, and that a prolonged boiling may negatively affect the water. On the other hand, I have learned that usually Japanese people boil the water and wait for it to reach "downwards" the right temperature.

What I usually do is to bring the water to the right temperature in my tetsubin kettle and keep my kettle on and off my electric plate (which has been turned off) for keeping and, later, increasing temperature through subsequent infusions (but for oolongs and puerhs my water reaches full boil). I prepare my water by keeping tap water in a jug for 12-24 hours, then I filter it through my Brita, leave a piece of bamboo charcoal in it during the night and warm (rather than boil) it with another piece of charcoal in the kettle.

I think I am going to make some experiment now, but I would like other teachatters' opinion on this. Maybe boiling is necessary for the bamboo charcoal to affect the water? Maybe boiled water is truly worse than water which has not reached the boiling point (and why?)? Maybe some teas are better with boiled water (Japanese greens?), while others (Chinese greens?) turn out better with "warmed" water?

Thank you for your suggestions.

A


PS Sorry if this has already turned up in a different topic.

[olivierco]

I always boil the water and wait for it to reach "downwards" the right temperature so that I am able to control the temperature without any thermometer. I don't see much difference in taste (as long as the water had been boiling only for a short time).

[Chip]

+ 1 ... however with thermometer usually for the first steep at least with most greens.

I always boil and cool down. Also doing so allows me to do 4-5 steeps without reheating the UtiliTea electric kettle, just heat once.

[Oni]

I watch the bubbles with chinese greens, and pour only 1/4 full, crab eyes water, with japanese greens I do a full boil, big bubbles breaking the surface, and I cool down for the desired temperature, and I use soft mountain spring water, it is very cheap, I am surrounded by mountains, I recall reading that water should not reach Dragon eye or old man water state or it will lose oxigen, and nitrates will transform into nitrites and some scientifically explainable way your tea will not taste good.

[Jayaratna]

I have tried to boil water and let it cool, with no difference in taste. Maybe one just has to avoid prolonged boiling.

[judyw]

Another vote for boiling and letting cool.

[Jasmin]

I use good filtered water to begin with, the same that I use to drink. I don't see a difference to letting it boil first, or using it before it comes to a boil.
If I would use the water straight out of the tap, I would definately let it come to a boil first.

[clareandromeda]

Im interested in this bamboo charcoal.... How does it work? Is it similar to the charcoal found in Brita and Pur?

[Oolonga]

For my greens I usually warm filtered water to the exact temperature I need without prior boiling. Sometimes I use the water that was previously boiled to brew oolongs or blacks and has already cooled down so I can use it for greens. I don't notice any difference in taste of tea though.

[MarshalN]

Always boil

[TIM]

Boil, age, boil again.

[Seraphsody]

My water is simply wonderful from the tap, so I just use that. ^_^

For green tea, I watch the water (usually tippy toeing from foot to foot) and let it go until slightly before it really boils.

For white tea, I watch (and tiptoe) and let it get until just after the small bubbles start to rise to the surface

For black and red I let it go until my kettle flicks off. : P

When I was young, my tea shop guy told me that was the way to do it, and I've done it that way ever since.

[Zanaspus]

I'll be different. I never let mine get to a boil. My reasoning follows;

The higher the water temperature, the less dissolved air it is capable of holding. Also, boiling removes temporary hardness from water. To my mind, airless, calciumless water tastes flat (boil some water, let it cool, drink it, and tell me what you think.) I have done it both ways in the past, but I find that never boiled water makes for a "snappier" tea.

Just my 2 nickels.

[Intuit]

>boiling removes temporary hardness from water

I wasn't sure about this point, but...

Temporary hardness, definition from wikipedia
http://en.wikipedia.org/wiki/Hard_water
Temporary hardness is caused by a combination of calcium ions and bicarbonate ions in the water. It can be removed by boiling the water or by the addition of lime (calcium hydroxide). Boiling promotes the formation of carbonate from the bicarbonate and precipitates calcium carbonate out of solution, leaving water that is softer upon cooling.

The following is the equilibrium reaction when calcium carbonate (CaCO3) is dissolved in water:

CaCO3(s) + CO2(aq) + H2O ⇋ Ca2+(aq) + 2HCO3-(aq)

Upon heating, less CO2 is able to dissolve into the water (see Solubility). Since there is not enough CO2 around, the reaction cannot proceed from left to right, and therefore the CaCO3 will not dissolve as rapidly. Instead, the reaction is forced to the left (i.e., products to reactants) to re-establish equilibrium, and solid CaCO3 is formed. Boiling the water will remove hardness as long as the solid CaCO3 that precipitates out is removed. After cooling, if enough time passes, the water will pick up CO2 from the air and the reaction will again proceed from left to right, allowing the CaCO3 to "re-dissolve" into the water."

Reading about this was pretty cool. We don't generally talk about temporary hardness in water quality/water treatment coursework in college. Most of the emphasis on carbonate hardness centers on permanent water hardness chemistry, processes and pipe fouling.

Edit: we do talk about temp hardness in advanced courses, with regard to boiler operations and maintenance.