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teasecret wrote: ↑

Thu Apr 04, 2019 12:23 pm

38 is not that low of a tds, especially with a total hardness of 25. Icelandic glacial water, while it has a tds of 62, the total hardness is 26 - almost identical.

TDS and hardness are often conflated and there's a lot of misinformation around. Hardness pertains to the calcium and magnesium carbonate dissolved in your water. In and of itself, it is only valuable to us tea drinkers because of the deposits that can be left behind in our kettles and teapots. It does not tell us much about flavor or body of the water, only how likely it is to form deposits.

When hardness and TDS are accurately measured, TDS will always be the same or higher than hardness since it is measuring all the solids in the water, not just the ones that contribute to hardness. Because the TDS is a measure of all the dissolved solids in the water it is the number that gives us some indication of the body of a water.

Iceland Springs Water has a TDS of 48 mg/L, which is quite light. Fiji is a popular bottled water for tea and it has a TDS of 222 mg/L, making it feel very thick. If you haven't tried back-to-back Fiji and a low TDS water like the ones you mentioned, give it a try. It's kind of cool.

In the past, it was generally agreed that water with a TDS of 50-150 mg/L or less was ideal since you did not want it to be either too thick or too thin. Friends in Taiwan regularly use spring waters with TDS ranging from 30-50 mg/L and they consider this ideal because it has a light body.

Something to ponder: perhaps a high TDS water would be good for teas with poor body, and low TDS would be better for teas with lots of body.

I can see what you’re saying, but I think total hardness doesn’t just mean how much scale. Why doesn’t it pertain to the body and even the flavor of the water/tea? Fiji water tastes thick and rich, and has 105 total hardness. TDS and hardness correlate, but they don’t always have to.
For the record, I could make 300 tds water by putting a teaspoon of salt in it. So maybe we should be looking closer at total hardness, permanent/temporary hardness, alkalinity, sulfate-chloride ratio, etc. to see what really specifically matters.

teasecret wrote: ↑

Thu Apr 04, 2019 9:40 pm

I can see what you’re saying, but I think total hardness doesn’t just mean how much scale. Why doesn’t it pertain to the body and even the flavor of the water/tea? Fiji water tastes thick and rich, and has 105 total hardness. TDS and hardness correlate, but they don’t always have to.

Both hardness and TDS are measured in the same units. So 25mg of the 38mg in a liter of your water is calcium and magnesium carbonate. You have 13mg/L that are other minerals and miscellaneous solids. That’s a delta of 38% that’s unaccounted for by using hardness as a measure for body.

teasecret wrote: ↑

Thu Apr 04, 2019 9:40 pm

For the record, I could make 300 tds water by putting a teaspoon of salt in it. So maybe we should be looking closer at total hardness, permanent/temporary hardness, alkalinity, sulfate-chloride ratio, etc. to see what really specifically matters.

Yes, if you could get a teaspoon of table salt (ignoring that it’s closer to 5700mg than 300mg) to fully dissolve in a liter of distilled water you would notice that the body of the water will be quite thick. Higher TDS equates to thicker body. Ok, your salt water tastes bad but we’re talking about the thickness of water not the flavor.

Neither value tells you much about how a water tastes. Hardness doesn’t tell you how the water feels in the mouth but TDS does.

Baisao wrote: ↑

Thu Apr 04, 2019 5:41 pm

TDS and hardness are often conflated and there's a lot of misinformation around. Hardness pertains to the calcium and magnesium carbonate dissolved in your water. In and of itself, it is only valuable to us tea drinkers because of the deposits that can be left behind in our kettles and teapots. It does not tell us much about flavor or body of the water, only how likely it is to form deposits.

I was under the impression that some tea compounds bind with calcium carbonate, and in my anecdotal experience hard water produces very thin and flat tasting tea, almost like the flavours are distant.
Found this article speaking about it, they obviously did not use comparable quality tea to the ones we brew but they measure some compounds after brewing and filtering which is interesting.

https://waset.org/publications/10005890 ... k-tea-brew

On the other hand one compound I noticed has a correlation with the body of a tea is either sodium or bicabonate, water I tried that gave teas a very thick body was very rich in both so I cant tell which is which since all other spring waters in my area are very low tds.

Water in question:
In sum I find though water hardness doesnt tell the whole story tds tells almost as little, as different compounds seem to affect the tea differently and higher tds= thicker brew doesnt seem to be an assumption we can make.

@gatmcm, you may have noticed that I have avoided the topic of taste and focused on the body of water. I am reluctant to go down the rabbit hole of how various minerals/chemicals/pH attenuate flavor as I have found the results to be much more complicated than "bicarbonate does x" and "calcium carbonate does y". I've been down that path and it's a fool's errand unless you are a food scientist, but I guess playing chemist can be fun.

Baisao wrote: ↑

Fri Apr 05, 2019 10:24 am

gatmcm, you may have noticed that I have avoided the topic of taste and focused on the body of water. I am reluctant to go down the rabbit hole of how various minerals/chemicals/pH attenuate flavor as I have found the results to be much more complicated than "bicarbonate does x" and "calcium carbonate does y". I've been down that path and it's a fool's errand unless you are a food scientist, but I guess playing chemist can be fun.

Oh for sure, I for one just tested the waters available to me and picked one, since we don't import water it wasnt particularly hard to test most of them. What motivated my post was that in my experience so far hard water made tea thinner and not thicker despite being much higher tds than the water I usually use.

I'm just saying that probably due to the bicarbonate and hardness making up a large portion of the TDS of that water, it provides a sufficient body for all types of tea. If it had neither of those, I doubt it would have much body at all.

teasecret wrote: ↑

Fri Apr 05, 2019 9:13 pm

If it had neither of those, I doubt it would have much body at all.

If it had 38mg/L of salt instead of calcium and and magnesium carbonate it would still have the same body. It would taste bad but the viscosity of the water would be the same.

Baisao wrote: ↑

Fri Apr 05, 2019 11:02 pm

teasecret wrote: ↑

Fri Apr 05, 2019 9:13 pm

If it had neither of those, I doubt it would have much body at all.

If it had 38mg/L of salt instead of calcium and and magnesium carbonate it would still have the same body. It would taste bad but the viscosity of the water would be the same.

Actually, it really does depend. Potassium chloride, commonly found in some waters, actually reduces the viscosity of water when added. Source: https://books.google.com/books?id=WdjNA ... er&f=false

Oh man, you have me rolling. Quoting a book from 1907, back in the dark ages of science, back when scientists injected undiluted absinthe into guinea pigs abdomens to prove it was poisonous.

And then! And then to prove your point that a mineral reduces viscosity— which would be really cool, btw— the amount of reduction was from 1.00 to 0.98!
Ok. It’s been fun. And I thank you for the belly rolls of laughter. Really. It’s been stressful lately and I needed that.

Take care and happy blogging!

Okay, I also have similar data from 2005... the belly laughter is quite unnecessary.
Enjoy your tea, that’s all I care about I guess!

Back with a new article, my top ten favorite teas! It'll be in two parts, part 2 comes out next sunday.
https://teasecrets.home.blog/2019/07/07 ... rt-1-10-6/
Let me know if you have had any of these. It was hard to pick.

Sorry for double post, but part 2 of my favorite teas is up.
https://teasecrets.home.blog/2019/07/14 ... rite-teas/

New post! 5 observations.
https://teasecrets.home.blog/2019/10/10 ... ervations/