The lively discussion that followed my post on how the British really cared about their tea reminded me of an issue that I had idly thought about some time ago when I visited relatives in New Zealand. They are Sri Lankan and thus, like the British, take their tea seriously so that they make sure that the ‘tea things’ (tea kettle, tea pot, tea, sugar, milk, cups, strainer, and spoons) are located in prominent and easily accessible places in the kitchen so that no one dies due to tea-deprivation. Their tea kettle is a powerful electric one that heats water very quickly, not the wimpy one that I have that you heat on the stove.
When I make tea, I only put sufficient water into the kettle that I needed for my tea, by first filling a cup with water, then pouring that water into the kettle, and repeating depending on the number of cups of tea I was planning to make. But I noticed that when they made tea they would hold the kettle under the faucet until there was much more water than they needed, boil and use it, and leave the remainder in the kettle to cool. Then when they needed to make tea again, they would throw away the water that remained in the kettle, fill it up again, and repeat the process.
This struck me as wasteful of energy (and water) and I asked them why they did this. It had never occurred to them to measure the water into the kettle, presumably because their powerful electric kettle heated the water up so fast, unlike my stove top one. Also electric kettles require a certain amount of water in the kettle to completely cover the heating coil at the bottom, though they used far more than the minimum required. But what intrigued me was their claim that one should never use water that has been boiled more than once to make tea. The video I linked to in my previous post also had that guy sternly telling the viewer that you should never do that but always use fresh water from the tap.
I had never heard of this theory, possibly because I grew up in a home in Sri Lanka that had domestic help and so never made tea myself. It appeared mysteriously out of the kitchen whenever I needed it. When I asked my relatives why they this was important, they couldn’t say, apart from some vague suggestions that it was bad for you or that it affected the taste of the tea. It seemed to be one of those pieces of folklore that are handed down from generation to generation and are followed unthinkingly. Off the top of my head, all I could think of was that since any dissolved gases that might affect the taste would boil off the first time anyway, boiling again would have no effect.
I meant to follow up on this question but forgot and this discussion made me look it up. There are some sites that recommend this and suggest all manner of scary things that can happen to those who used re-boiled water but Karl Smallwood seems to have gone into this issue on great detail (you can check his sources at the bottom of his post). He says that unless you are boiling down a massive quantity of water to a tiny amount and thus hugely magnifying the concentration of naturally occurring impurities in the water that do not boil away, there is no benefit to avoiding re-boiled water.
As for the taste question, there seem to be no studies that suggest that taste is affected by boiling water more than once.
While I could not find any studies on the idea of twice boiled water changing the taste of tea, we can at least look at the mechanism involved to get an idea on whether it is likely or not that such a taste shift is occurring.
For starters, many claim the taste difference comes about due to twice boiled water having less dissolved oxygen in it, referencing the fact that, as the water temperature increases, the solubility of oxygen decreases. This latter fact is absolutely true. The former is not.
You see, at 100˚C (boiling point) the concentration of dissolved oxygen (assuming normal atmospheric pressure) will ultimately be near zero, whether it’s once or tenth boiled water. How long you boil the water does come into play somewhat, but even then the differences are minimal, with dissolved oxygen levels at 1 atmosphere and 0°C on the order of 15 ppm, compared to approximately 5 ppm at 50°C and near 0 ppm at 100°C.
“But my tea tasting palate is extremely refined and able to detect even the smallest of changes of dissolved oxygen levels,” you say as you idly clean your monocle.
It doesn’t matter.
Once the water is allowed to cool back down, its dissolved oxygen levels will once again begin to rise to normal levels given atmospheric pressure and temperature. (CO2 levels, which can affect the taste, will also return to normal.) Given this, the second time you bring the water back up to boil, things like the oxygen level are not going to be any different than the first, assuming equal boiling times and/or temperature levels.
That’s not to mention that the idea that more oxygen = better tasting gets into the aforementioned debate on what does or does not taste better when making tea- everyone’s got their own preferences. And if you’re curious, there have been studies (Pangborn & Bertolero 1972, Faust & Aly 1998) that have indicated that dissolved oxygen actually doesn’t noticeably impact the flavour of water, though it should be noted that those studies weren’t dealing with brewing tea, and it is possible (even probable) that dissolved oxygen could be interacting with elements of the tea to change the flavour (similar to what happens with wine). But either way, whether once, twice, or thrice boiled, you’re getting essentially the same dissolved oxygen levels, assuming you boil/steep the same way each time.
I recall the time when I was in a hotel restaurant for breakfast and overheard the woman at the next table order orange juice. But she asked the waiter whether the juice was from concentrate or not. He confidently said that it was not but she was not convinced. She asked to speak to the head waiter and he too said that it was not but seemed to waver a bit. She then asked for the manager and he said that they did not actually squeeze the oranges in the hotel but it came from a supplier and that he thought it was not from a concentrate but could not guarantee it.
While I was impressed by the woman’s dedication to avoiding orange juice from concentrate, I could not see why, if she could tell the difference, she did not simply taste it and check for herself. If she could not tell the difference, then why did it matter, since I doubt that orange juice from concentrate is actually harmful to you?
People who think that they have very discriminating palates when it comes to wine, tea, coffee, orange juice, and the like often cannot tell even major differences when subjected to double-blind taste tests. No amount of science is going to persuade such people that they may be imagining that they can detect subtle flavor differences. But clearly simply knowing some facts about what they are drinking affects their enjoyment. So as with whether to add milk and sugar to tea, we should let people do what they want since it is pretty much harmless either way. If they think it affects the taste, so be it.
Since “taste” is a phenomenon of perception, can’t we reasonably say that “taste” incorporates the entire system by which we perceive flavor -- which would necessarily include its interpretation? If that’s the case, yes, once you know that you’re drinking cheap plonk wine, it “tastes” inferior to the multi- hundred-dollar conoisseur’s delight, because knowing its price is part of the “taste”
Of course that reasoning would lead us inevitably to believing (as I do!) that if you can fool your guest into thinking they’re drinking a glass of Opus One, then for all intents and purposes, they are. Because the glass of Opus One is also a performance and not an isolated thing. Aesthetics has to incorporate the values of the consumer as well as any inherent properties in the artwork being consumed, because it’s always a matter of interpretation.
This now makes me wish…. OK. I used to have a friend who was very suggestible to hypnosis. It was fascinating. With permission, I did a few experiments. At one point I experimented with inducing the memory of senses -- which worked really well. “Remember what roses smell like. Remember the aroma and how it seems to fill your head. When I say ‘roses’ today you’ll vividly smell that aroma.” -- that kind of thing. I wonder what would happen if, instead of inducing a memory you induced a superlative, “Remember the best wine you ever had? How rich but sweet and biting it was? Remember … Now, the next thing you will drink is better than that. The sweetness is deeper and richer. The color is more red and perfect..” etc. Too bad my subject moved away, it would be interesting to see if they could experience something better than they had ever had. It’s just a matter of imagining that the knob goes up to 11.
That’s what I was thinking. If my re-boiled water is now 450 ml (and that’s grossly overestimating the amount of water that is boiled off) instead of 500 ml I now have the same amount of “undesirable” compounds as in 500 ml of fresh water. Clearly we do not monitor our water intake that closely for this to matter.
Marcus
Let me order some vanilla ice cream and pour it on top!
I’m wondering how this would be going with somebody like me for whom “sweet” and “good wine” do not go together.
It should be noted that most of what we perceive as taste is actually done by the nose. There are only five types of taste receptors, after all (sweet, salty, bitter, sour, and umami.) So something with many volatile components, such as wine, can taste quite differently from one batch to another. Different tasting orange juice, however, will depend much more on how much sweet and acid is in the juice, and using concentrate actually makes it easier to get a consistent flavor.
As for “twice boiled” water (never mind how really old all the water on this planet actually is) the closest such argument I’ve seen had to do with how hard water affects the ability to extract volatiles from plant material. Water can only hold so much in dissolved material, so a lot of dissolved calcium carbonate and other minerals just has less “room” to hold what gets extracted from tea, resulting in a weaker flavor. Hard water can also taste “off” compared to filtered or distilled water, but that is true whether it has been heated once or a dozen times.
Boiling more water than needed for tea (and coffee) actually is wastefull, if my calculations are correct. I am drinking 1 to 1,5 l tea per day. I do measure the water prior to cooking with the cup. If I did not do so and cooked say 20% more per each cup, it would amount to 0,2-0,3 litres a day, that is 73-109,5 litres of water per year heated up to boiling temperature and needlessly dumped. This ammounts to approximately 6,8 to 10 kWh. This is 0,7% to 1% of average yearly energy consumption per person where I live (which is 1 to 2 MWh depending on whether you heat your washing water with gas or electricity).
To me that seems a lot of wasted energy just for tea. And I think tha worldwide an awfull lot of CO2 pollutions would be saved, if only people took care of these little “banal” wastes.
Orwell: “tea should be made in small quantities — that is, in a teapot.” G.O. would be appalled at the idea of boiling water in a pot and pouring it into a cup to brew. It follows from his advice that one should boil only the desired quantity of water.
As for boiling water twice, as Gregory suggests, the more steam is evaporated from a pot, the greater the concentration of non-volatile solutes remaining. This would include calcium and also trace minerals including lead. On the other hand, prolonged boiling reduces the amount of chlorine used in water treatment by public utilities in many cities. Chloramines evaporate slowly and can be reduced by prolonged boiling.
Have y’all ever heard of Adam Ruins Everything? It’s become one of my favorite shows. Thought I’d link to a couple clips here dealing with wine and orange juice, which both suggest a lot about the myths we have about food, drinks, and taste:
Adam Ruins Everything -- Why Orange Juice Is Totally Unnatural
Adam Ruins Everything -- Why Wine Snobs Are Faking It
That second is set up to be kinda mansplainy, so sorry for that. But it is interesting.
As a person who grew up without drinking any tea or coffee, I had to learn all about tea from my wife who is an avid drinker of both substances. Nevertheless, as an engineer and experimenter I’ve worked out the following principles:
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A good cup of tea can only be made when all parts of the process are adequate.
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Good quality water is important. My wife never made tea with anything other than rain water. Mains water contains too many impurities, spring water or filtered water would be suitable. Friends would come up from the city and exclaim how wonderful the tea tasted at our place. Our house is in a good rainfall district and has 24,000 gallons of rainwater storage so we live on it all year round even during drought years.
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A quality stainless steel kettle will not impart undesirable taste on the water. When our last electric kettle died I fished out an old plastic kettle and the taste was distinctly worse. The new kettle is fine and after 12 months still doesn’t have any scale in it due to the soft rain water.
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Quality tea doesn’t need to be strong to be drinkable if the water is good. I’m happy to use loose leaf or tea bags but the bags get dipped for a few seconds only, to be reused 1-2 times later. I take tea at around 10% the strength that some of my friends serve it, makes for a little funny moment at times. Watching a person go wide eyed compulsively jiggling a bag a few more times for you after asking them for very weak tea is quite funny too. I tip 90% of it back out and ask for some hot water. One friend of mine got the hang of making what he termed “crickets widdle” for me after a while.
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Milk to taste, a tiny amount is all that is needed if you like the taste. I won’t use anything other than fresh low fat milk as that is my preferred taste. Black is good too.
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Reboiling water is fine so long as it is good water. I often use the bit of water left in the kettle after making hot drinks to rinse cups and spoons. This saves running the hot tap long enough to get warm from the storage tank.
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Anyway, have a nice cuppa to your own taste, it would be boring if everyone was exactly the same.
@ david (#5)
Calcium carbonate experiences retrograde solubility. Heating up water makes CaCO3 LESS soluble, not more, and thus it precipitates out. This is why we get scale in kettles, shower heads, etc. So while boiling water twice concentrates some impurities, it also removes even more of the hardness.
As for this issue at large, I have heard it theorized that it’s a matter of dissolved oxygen, and that oxygenated water makes tea taste better. Boiling drives some oxygen out of water, and the more you do it, the less O2 remains. I used to work in a chemistry lab and whenever we were making stock solutions of compounds that reacted with oxygen (particularly sodium sulfide), we’d boil the water for several minutes and bubble nitrogen through it to ensure no O2 remained. However, I’m not sure how long water needs to boil to remove enough O2 to change the taste of tea made with that water (assuming that this does indeed happen). When I make tea, I boil water twice, briefly, the first time to heat the pot up (water that is discarded), and the second time for the tea proper. This is how my parents taught me, and their parents taught them. No idea whether this methodology truly produces better-tasting tea, or whether it just makes for a pleasing ritual that has no actual effect on the chemical content of the final beverage.
Boiling extra water is no waste if you use the cooled boiled water for drinking. It’s certainly better than buying drinking water in a bottle.
Charly
That’s the one argument I accept. It uses more energy than needed. 1-2MWh? I’m always wondering how people manage to use so much electricity…
Chris Whitehouse
Well, I live in a place with excellent tap water so it is still wasteful compared to just opening the tap. And it does taste stale.
I think this may have started as a regional thing. Where I live, the water from the tap is delicious and soft, and I’ve owned my kettle for nearly 20 years. A friend of mine who lives in the south would sooner drink his own urine than what comes of his tap, and he has to buy a new kettle every year or so. When you put water in his kettle and swill it around, it sounds like a bag of gravel… which is what it is, effectively, because of the CaCO3 in there. It’s horrible. So if you live where the water is hard I can well understand wanting to boil the water as little as possible.
I wish I hadn’t got used to sugar in tea. I wish I could drink it without. Partly because it marks me out clearly as a member of the morally inferior lower classes, but mainly because it’s probably the single largest source of refined sugar in my diet. This is not harmless. Obviously I could stop taking sugar, but that would make tea intolerable. And I could stop drinking tea, but I’m English and are you MAD?
You can wean yourself off it fairly quickly -- the trick is not to try to cut it out all at once. Just reduce the amount of sugar you take a little at a time… You might be surprised by just how quickly your palate adapts.
It’s actually a worse than that, because you’re neglecting the energy needed to collect, treat, and distribute the water. I’m having trouble laying my hands on handy statistics in useful units, but it’s certainly not insignificant.
I believe that Orwell is referring to brewing tea in the correct manner, i.e. boiling the water in a kettle and then transferring it into a (warmed) teapot to brew the tea, before finally pouring it into a cup to serve. You need to boil slightly more water than you actually need, so that you have enough to warm the teapot. Since he says “in small quantities”, and given the period in which he was writing, he is most likely objecting to the practice of preparing large urns of tea and keeping them hot all day, as was common in work or institutional settings in that era.
I had heard -- many times over many years -- a version of this argument where the level of dissolved O2 (purportedly) affects the brewing process. As one with a near-obsession for tea, as one with quite the sensitive palate, and as one with a greater tea collection than anyone I know (and I deliberately befriend others who savor tea) I have never tasted any difference i can reliably attribute to multiple boilings of my tea water.
Given my experience refuting this hypothesis to which so many desperately cling, I can only howl in response:
I have seen the best minds of my generation destroyed by madness: parched, hysterical, naked, dragging themselves through youtube comment threads before dawn looking for an angry fix, assam-headed hipsters burning for the ancient heavenly connection to the leafy dynamo in the machinery of water.
…Dreams! adorations! illuminations! religions! the whole boatload of sensitive bullshit!
Mano,
My wife’s family is very serious about their tea and they adhere to the boil once rule.
I’ve never questioned the rule because of a related experience when I was a child. Our household used cistern/rain water on a daily basis, but once we had a contamination issue for about a week and we had to boil all our drinking water. The last step of the process, before the water went into jugs, was to pour the water back and forth between two large pots to aerate the water so that it didn’t taste flat.
This is, of course, purely experiential, and I’m now motivated to do my own series of tests to see if I can first detect any difference between boiled, unaerated water and boiled aerated water and the same two sources used to make tea.
Cheers,
Jeff Hess
Have Coffee Will Write
Citric acid. Put it into your kettle twice a year or as often as necessary (I do so when small pieces of chalk appear in my tea, eh, herbal infusion), bring to boil, clean with lots of fresh water, as good as new. There’s no reason to throw a kettle away because of it.
Dunc
Only if you throw it out
sonofrojblake: “Obviously I could stop taking sugar, but that would make tea intolerable. And I could stop drinking tea, but I’m English and are you MAD?”
Switch to green tea. No milk or sugar needed. The first cup or two may taste a bit bitter, but you’ll soon get the hang of it. Like your first taste of lager. I’ve never looked back. (But I still drink also coffee and ale.) Just remember that green tea is not made with boiling water. Around 70C is best.
All the tea drinkers I know always measure the water (tea leaves are always added into the boiling water) .
I wonder what the tea snobs would make of the Indian road side tea where the tea is boiled over and over again . New water/milk/tea leaves are added into the existing mixture and the process is repeated.
@Giliell, professional cynic -Ilk
My mom uses the peel of a used lemon to accomplish the same thing
@sonofrojblake
I halved the quantity of tea I drink to halve the sugar for the same reason as you (rather than the approach that Dunc suggests of gradually reducing sugar) . I like the way tea tastes with sugar too much to give it up.
deepak shetty
Or a Russian Samovar (with jam stirred in instead of sugar)
My dad and an aquaintance were very amused at pouring cheaper alternatives in fancy scotch and cognac bottles and serving it to folks who thought they could tell the difference but couldn’t.
That inability was also the basis for the Pepsi challenge.
We boil water (for any purpose that requires boiling) in an electric kettle where the coil is not in the water. We use filtered water (from those filters that go on the tap). Thus we avoid calcification, and also the oxidation of the coil by the water.
The main use of boiled water in our household is mate, which my husband drinks. While he has some gourds, he switched to drinking mate out of mugs. There is a layer of yerba at the bottom, and he keeps adding more boiled water. One does not measure water for mate, you just keep almost-boiling water at hand and keep replacing the water that was consumed.
The rice of something greatly influences how much people like something, yet it is often not very related to the product itself but depends on where you are.
First of all, yes there are quality differences. A quality wine or Scotch requires some work. You cannot grow as much wine as possible one a given area and get good wine. The leaves can only produce so much sugar and the amount of grapes that goes into matters. And then a good winemaker usually selects the grapes carefully, tossing out even more while for the cheap stuff everything gets used.
BUT, and this is a big BUT, this effect really wears off at a certain point. So yes, there’s a difference between a 3 bucks bottle and a 10 bucks bottle. Only that my 3 bucks bottle is a 10 bucks bottle in the UK and my 10 bucks bottle is something really fancy there. And we once bought some delicious 3 bucks a bottle Rioja at the vinery itself…
# 8 chris_devries
When I make tea, I boil water twice, briefly, the first time to heat the pot up (water that is discarded),
From something I read, {or perhaps heard on the Antique Show (UK}the idea of warming the pot first seems to have been a result of 18th C porcelain makers in Europe inability to duplicate the quality of Chinese glazes with the result that pouring the entire quantity of hot water into a cold pot meant no more pot.
And who knows, it may even make a difference in the taste, as well.
jrkrideau
Well, it will keep the heat for longer, which may influence taste.
Personally, if my coffee mug is straight out of the dishwasher, I’ll rinse with cold water because I don’t want to burn my tongue…
False, and stupidly false at that.
It takes energy to heat up water, and that energy is proportional to the amount of heating and the mass of water. If you boil twice as much water as you need, you are using twice as much energy and wasting half of it.
On the subject of the “powerful electric” tea kettle itself, it might not have a resistive heating element at the bottom, but two metal plates connected directly to the mains voltage that passes the electric current directly through the water. if the kettle has a warning to only use plastic or wooden spoons and never metal ones, that would make sense.
And if you think that having electrically live plates in a tea kettle is dangerous…you’re pretty much correct. For all that we’re warned to not blow-dry our hair in the bathtub, that’s basically what they’ve done here.
EEVblog #873 -- World’s Most Dangerous Consumer Product!
https://www.youtube.com/watch?v=f14nv3uf2ik
Inside a dodgy Turkish “stinger” kettle.
Wait a minute!
You guys have tea kettles? Wow.
jrkrideau @ #27:
I have an electric variable temperature tea kettle made by Bonavita. I got it from Amazon for $99. It allows me to choose what temperature to heat my water to, with a range from 145*F to 212*F. It may not be 100% accurate, but it’s close enough to make brewing different kinds of tea easier.
I’m also looking to get this: Sharp Tea-Ceré
It’s made to grind Tencha into Matcha, but the functionality lets you grind any tea into powder to then be brewed. I’m excited by the idea of powder white tea, powdered oolong, powdered jasmine green, powdered Gyokuro… it could be so awesome…
Giliell, professional cynic -Ilk@2
I’m surprised you haven’t been kicked out of Germany!! 😉
I never really drank except for the rare glass of wine because, like Mano, I simply never really liked the taste. I did discover a few types of wine and beer that I enjoyed when I lived in Germany though (one being a German Riesling) and now my palette has expanded quite bit when it comes to alcoholic beverages. I like what I like though, and price and snobbishness don’t really enter into it. I don’t pretend to have a really well developed palette, but I can taste the differences in many different whiskeys and cognacs, as well as wines and beers.
As for boiling water twice: if it’s close to pure H2O, boiling it won’t affect it, and as far as concentrating the impurities of tap water, unless you’re boiling it to the point of a reduction, it wont’ affect anything.
The point about people who think they have super refined palettes, but failing in a double blind test is interesting, and not surprising. There are, however, some people who really do have that well of a developed palette, but it’s usually limited to one or two specialties, from what I’ve seen. (For a good instance of this, google the episode of Mythbusters about vodka).
Gilliel @ #2:
(I can’t believe missed this until now.)
That’s hilarious. I’m the exact opposite with wine. I can’t seem to drink a wine that isn’t sweet. To be fair, I’m picky even with sweet wines. I’m not one for Manishewitz. But a good Moscato, or Black Muscat, or Riesling, and I’m there. I also recently discovered Ice Win, and oh. My. God. It was everything. But most wines that aren’t sweet are largely just… bitter… to me. And I don’t really like bitter.
I’m the same way with rum, although I prefer natural sweetness to rums with added sugar. With scotch, I like it either naturally sweet (like aged in sherry or port casks, for example), or extremely peaty/smokey.
I refuse to touch beer. Every beer I’ve ever had has been nothing but bitter. Yes, even “light” beers with “lime”. I can just barely tolerate Abita’s Purple Haze, and also (though to a lesser extant) Blue Moon. But otherwise, beer is a big no for me. Although, oddly, I do love cooking with it (beer batter on onion rings, or fish, or chicken, is amazing, and I once made pancakes with just a hint of Guiness, and they were phenomenal, although that’s probably because I also used Bailey’s Irish Cream… 😀 ).
As for tea… I will always have a soft spot for southern-style sweet iced tea (grew up in Georgia, after all) and raspberry sweet iced tea. Plus, AriZona’s Green Tea with Ginseng and Honey is an outright addiction (there was a point in my life where they really should have paid me for all the advertising I was giving them; plus I was buying cases of it from Costco… and I still drink it). But ever since really delving into the world of loose leaf teas, especially Japanese and Chinese greens, I prefer a tea brewed right with no cream or sugar. And in the summer, I’ll just do one of those as a cold-brew (which takes around 8-12 hours depending on the tea).