Always boil water?

[t-curious]

I watched this YouTube where the guy said you should always bring water to boil for making tea. That if you needed cooler water, to let it cool from a boil. He said electric kettles with preset temperatures were convenient but don't make suitable water for tea, unless they bring the water to boil first.

Anyway, paraphrasing there but that's the gist I got. Any credence to this or is this just folklore?

Thanks,

Kent

[pedant]

any teaching presented without rationale is hard for me to get behind

same for warnings and notes taped to equipment. if someone doesn't care to explain, i don't care to listen.

[There is no self]

I watched this YouTube where the guy said you should always bring water to boil for making tea. That if you needed cooler water, to let it cool from a boil. He said electric kettles with preset temperatures were convenient but don't make suitable water for tea, unless they bring the water to boil first.

Did he say why though?
I'm not sure whether it makes much of a difference either way, although Baisao explained in the Water thread that boiling too much does things to the minerals (I'm also paraphrasing) so if anything I'm more inclined to say it's the other way around.

[.m.]

Cooled down boiled water tends to taste a bit different then unboiled. Fuller, sweeter. I guess depends on the mineral content, the kettle etc. Some hydrocarbonates may also precipitate.

[tjkdubya]

Fully boiling helps to precipitate the dissolved bicarbonates into insoluble carbonates (they "fall out" of the solution), reducing the hardness of water. See "temporary hardness" section here:

https://en.m.wikipedia.org/wiki/Hard_water

This is also why pre-boil TDS numbers do not always tell the story. Two waters may have the same TDS starting out, but due to the different levels of bicarbonates vs sulfides/chlorides, end up with different TDS after boil.

Fully boiling also helps to reduce any residual chlorine, if you happen to be using chlorinated filtered tap. Heating water in general will tend to do that regardless, but it's a matter of degree...

[tjkdubya]

None of this can tell you which water is "better." We can talk about how the world works, how water chemistry affects tea brewing, etc., but at the end of the day which water tastes "good" with which kind of tea is a subjective decision, on a personal level and perhaps on a cultural snowball level.

Sometimes if I feel like a bit harder water with a certain green tea, I will just heat to 80C or whatever, instead of boiling then cooling.

[Baisao]

I can’t explain it but boiled and cooled spring water tastes different to me than spring water warmed to temp. In these cases the target water temp was 60°C and the “boiled” water was heated to 90°.

The notion that over-boiling water creates an unpleasant taste because it has less oxygen doesn’t pass muster. Oxygen levels saturate almost instantly as the water cools. And yet over-boiled water tastes unpleasant even when brought down to lower temps, like 60°C.

As @There is no self alluded to and as @tjkdubya elaborated on, I have witnessed scale precipitate out of boiled spring water (Crystal Geyser, Ouchita Source).

Something I would like to mention from my experiences with sourdough baking and entomology: science has not thoroughly explained/described as many things as we may comfortably think it has. This isn’t because of some failure in science to apprehend unknowables so much as there are more things to be explained than there are scientists, time, and funding.

[_Soggy_]

Fully boiling helps to precipitate the dissolved bicarbonates into insoluble carbonates (they "fall out" of the solution), reducing the hardness of water. See "temporary hardness" section here:

https://en.m.wikipedia.org/wiki/Hard_water

This is also why pre-boil TDS numbers do not always tell the story. Two waters may have the same TDS starting out, but due to the different levels of bicarbonates vs sulfides/chlorides, end up with different TDS after boil.

Fully boiling also helps to reduce any residual chlorine, if you happen to be using chlorinated filtered tap. Heating water in general will tend to do that regardless, but it's a matter of degree...

It is best to filter out chlorine in the first place since it takes a lot of energy to boil out all the chlorine(should I mention dissolved oxygen or not? lol). Also, many municipalities use chloramine instead of chlorine to chlorinate the water supply. This chloramine is a more robust bond with water and doesn't evaporate at the rate chlorine does when it leaves the pressure of the water supply(I assume boiling takes longer vs chlorine as well).

[Ethan Kurland]

I can’t explain it but boiled and cooled spring water tastes different to me than spring water warmed to temp. In these cases the target water temp was 60°C and the “boiled

As There is no self alluded to and as tjkdubya elaborated on, I have witnessed scale precipitate out of boiled spring water

If you can taste a difference, then there is a difference.

I think scale precipitate can come out of spring water that is not heated to a full boil. (At a heat of 95C the water touching the bottom of a kettle might be around 100C while the water closest to the top is closer to 90C. I don't know. I do know that when heating to 96C for many sessions over a few days, a small amount of white particles can be seen at the bottom of my kettle. I like to empty the last couple of ounces of water from the kettle into a glass pitcher sometimes. I let the "salts" settle, then pour out as much of the water that I can until I get to the minerals that seem like they should be sent down the drain. Much less often, I clean the kettle.)