All steamed up about reboiling kettles
Posted by Jon on Tue 26 May 2009Categories: Food , RSC in the media | [55] Comments
2009 marks the inexplicably overlooked 50th anniversary of the automatic electric kettle, the true patriarch of this noble dynasty being the Russell Hobbs K2.
As reported in today’s Metro, we’re appealing to the public on this contentious issue: should you reboil or refill a kettle for that second cuppa? The best answer wins a trip down to London for two people to indulge in a British instution: tea at the Ritz.
There’s a huge body of opinion that maintains a bad-tasting brew is inevitable if you reuse water once boiled – some say it rids the water of taste-enhancing dissolved oxygen gas. There are others who heard from their grannies that reboiled water causes cancer.
But some say that the difference in taste and composition is minimal, and a new draught of water is just a waste of a precious resource – not to mention more expensive. Still others say it makes no difference at all!
Arguments about limescale, dissolved gases… surely this is just chemistry, yes? So there must be a scientific explanation for all this.
Explain your choice of reboiled or reused water, in a clear and scientific manner, in a comment to this post. The answer we judge to be the best will win a trip for two to London, and tea at the Ritz hotel on Piccadilly – incidentally just a few steps down the road from home of the RSC, Burlington House.
We’ll be closing comments on 30 June, so pull up your favourite search engine, give your granny a ring and present your theory below!
Click here if you can’t see the comments box.
Tue 26 May 2009 at 15:36
The purpose of refilling the kettle is to rinse out the flakes of limescale that have accumulated in the kettle the last time it was boiled, as no one wants limescale flakes stuck between their teeth.
Tue 26 May 2009 at 15:39
Thanks David. This may indeed be true for some areas of the country, but where I grew up – South Wales – we had some of the softest water in the country, no issue with limescale at all, yet still my Nan insisted on fresh water for tea!
Tue 26 May 2009 at 15:55
It is a problem in London as it is a hard water area, in fact the accumulation of limescale in the kettle will reduce the energy efficiency of the kettle and thus it is advisable to clean the kettle between uses. The same is true for rotary evaporators used in the lab!
Wed 27 May 2009 at 05:38
I use one of those electronic gizmos that (supposedly) removes limescale. Their instructions are to empty the kettle of any unused water as the wonder gadget doesn’t work with once boiled water. It also improves their dividend from the water company.
Wed 27 May 2009 at 06:59
The maker of my electronic gizmo scale remover told me to replace boiled water in the kettle. By so doing I improve their dividend from the water company
Wed 27 May 2009 at 13:57
I would not reboil as boiling produces limescale which reduces the calcium, not good for our bones.
Also dissolved gases in the water are further reduced .
Wed 27 May 2009 at 16:15
The perfect temperature of boiled water will enhance the final tea taste. As water boils oxygen is released and oxygen is necessary for the tea’s soluble essential oils to react with water.
The essential oils in black tea are responsible for much of the taste and will only be released in boiling water , but if we boil the water too much we boil the oxygen out of the water and stop the essential oils binding to the water molecules/
If using an electric kettle one always overboils the water which is fine for mass produced tea, but not for rare and fine teas , where the flavour will be spoiled.
Thu 28 May 2009 at 05:56
I strongly feel that we can reboil the water. Reboiling will not change the chemistry (if the water is free from any dissolved compounds). If it contains dissolved compounds the taste may change as we reboil. The bad taste is from nano-carbon suspension. (I do not have a scientific explanation for this). Why i feel this is true because in earlier days in our rural areas people boils water in an open container with fire woods. The people say that the water has a taste of smoke. But the taste was like carbonated water. So i feel it is nano-carbons. The same might be happening in reboiling.
obviously people will ask from where the carbon comes in reboiling.
Thu 28 May 2009 at 05:59
Correction
Line 7 should read
But the taste was not like carbonated water.
Thu 28 May 2009 at 12:12
The taste of water is predominatly caused by dissolved minerals. Some of those minerals are bicarbonates, which will be removed when the water is boiled:
Ca(HCO3)2 —> CaCO3 + H2O + CO2
According to the ‘Typical Analysis’ data on a bottle of Volvic mineral water, the total dry residue is 130mg/L. If we subtract the 31.7mg/L of silica (which I thought was insoluble?!), we are left with 98.3mg/L of dissolved minerals, of which 71.0mg/L are bicarbonates. Since 72% of the dissolved minerals are bicarbonates, boiling the water is going to have a significant affect on the taste of the water.
Fri 29 May 2009 at 13:14
Reboiling water removes the dissolved gases and also the hardness. It flattens the taste of the tea. Use a filter eg Brita
Fri 29 May 2009 at 22:02
As you should only boil the amount of water you need at any one time so as not to waste energy there should never be the option to reboil!
However should you be faced with the choice to refill or reboil, the kettle should always be refilled with fresh water for each use to reduce limescale depositing: Preventing limescale building up will maintain the heating efficiency of the element and ultimately increase the appliance lifetime. The net energy costs will therefore actually decrease when compared with reboiling (and more importantly it keeps your nan happy!)
Sun 31 May 2009 at 05:52
Dont boil at all ,steep at 70 dgrees c ,ketel can have thermo control for the range upto 80 degrees c for ctc teas.All teas of this world will yeild their goodness around 70 degree.
Mon 1 Jun 2009 at 10:41
I seem to remember being told by tea-experts that reboiling the water will reduce the amount of oxygen dissolved in it, thus changing the flavour.
In a footnote I think the acceptable range of temp for tea ranges from about 75C for green tea, to 95C for an oolong or equivalent.
Tue 2 Jun 2009 at 19:07
I think that people might change the water everytime because if someone were to sneeze or cough or do something disgusting near your kettle then you wouldn’t exactly want all their germs and bacteria in your water therfore you would cahnge the water wverytime just in case.
Thu 11 Jun 2009 at 12:40
I’ve not noticed any difference between tea made with the same water boiled for the first time or several times (assuming the same amount of tea is infused for the same length of time). I think it has a lot to do with the marvellous variety between individual tastes, and highlights the pleasure people get from having a minor ritual about how they like their tea. So long as we enjoy our cuppa, does it really matter?
Fri 12 Jun 2009 at 16:10
I think we should expand the debate to whether or not the milk should be added before or after the tea is poured…..
Fri 12 Jun 2009 at 23:22
@ Martin Rose:
Seconded! I’ve heard plenty about denatured proteins which I’m not convinced by, and poor-quality china not being able to take the boiling water in the olden days, which I find more believable.
Anyone got any conclusive answers in that department?
Sat 13 Jun 2009 at 08:01
My choice would be fresh water everytime!I believe that the orginal debate stems from appreciation of the delicate tastes of fine teas.
A re boiled kettle uses water that may have ben standing for a while, therfore it’s not fresh. As water is boiled, oxygen is released. The more the water is boiled, the less oxygen it contains, this in turn, effects the taste of the tea as oxygen in the water is needed to bind the essential oils in the tea to the water molecules. This can cause the clean, crisp, taste of tea being tainted.
One last point is that re-boiling water can increase the concentration of inpurities and other mineral contaminates – which is particulary important when making babies’ bottles. Although this is less important when making the average cup of tea.
Wed 17 Jun 2009 at 08:07
I really don’t think anyone who has drunk tea made from water from an urn (that has probably been held near boiling from anything from half an hour to the best part of a day) should be in the slightest concerned about re-using the water.
Tue 23 Jun 2009 at 15:48
This must surely be the most authoritative scientific reference and explanation as to how to make the perfect cup of tea (dare you suggest otherwise?)
- the freshly drawn v. previously drawn water issue is addressed at the bottom of the first page.
http://www.rsc.org/pdf/pressoffice/2003/tea.pdf
Fri 26 Jun 2009 at 11:45
I am not sure where everyone gets the idea that reboiling results in more limescale. There is a fixed dose of minerals in each fill. This will precipitate out when the water is boiled. Every time fresh water is added to a kettle and boiled, a fresh dose of dissolved minerals will precipitate, resulting in more limescale buildup. To minimise limescale buildup it should be much better to reboil, particularly in hard water areas.
Fri 26 Jun 2009 at 11:56
I have a water meter, so I only put in enough water to make a cup/mug/pot (as required), and most of the time there’s so little left the remaining drops go in what ever is sitting waiting to go in the dish-washer.
My brother (also metered) does the same, so I suspect much of the re-boil vs. new water must be coming from un-metered people – you may need to take that into account (but I’m not sure how you could differentate in the debate!).
Simon
Fri 26 Jun 2009 at 11:59
Right then. Here goes.I reckon that the theory of no re-boil comes from a variety of sources:
Where I work (in Derby) we have an urn for the water, i can supply pictures of the limescale build up if necessary, it is awful. This is inevitably one instance where reuse of the water is horrible just due to the limescale flakes (as per David James at the first post).
Add to this the fact that the predominant Major Aquifer in the UK is the chalk that supplies the south east (most populous) area of the UK the fact that a few sheep in Wales and other minor areas might be privvy to really soft water is barely a counter at all, the majority of people aren’t and wives tales and the like come around by trend patterns and not outliers. Ergo if most people are exposed to hard or relatively hard water then this would be a trend.
Dissolved oxygen is important for a reaction with tannins to produce a flavour or ‘body’ for the tea as they do in wines. So teas can ultimately taste weak, empty and pointless. There’s basically less for the human taste buds to pick up with regards to the compounds present.
Milk is not really an issue as this is just adding more subjection to the problem. Ever tried green tea from reboiled water…. it is RANK!
With reboiled water the gentle flavours of jasmine bud tea, oolong and the variety of bergamot teas are masked by an almost fustiness.
I don’t even have to boil water to know there is a major difference. The fresh water from a tap and the glass of water that has been on my bedside table for 4 hours have completely different tastes.
Water that has been boiled in a kettle produces more H3O+ ions and I reckon that this picks up stuff from inside the kettle (not very scientific but then I don’t know what goes on in there). stuff probably doesn’t taste very nice.
Well those are some of my points, I could go on for days but I really need a cup of tea…….
love
Rusty Bullethole x
Fri 26 Jun 2009 at 12:05
Since many tea drinkers will adulterate their freshly boiled / reboiled cuppa with large dollops of milk and sugar is this arguement not a bit superficial?. The quality of the brew will depend on the concentration of tannins etc. leached from the tealeaves (one bag or two?), why else have the tea bags with room to move the leaves around. Should we perhaps seek to standardise the taste assesment e.g. 5g +/- 0.1g of best Typhoo (or whatever fills your cup) at 90 +/- 2°C (you can tell were an accredited lab). I will watch the thread with interest.
Fri 26 Jun 2009 at 12:08
Well, the answer very much depends on where you live. I once lived in Kent, here you had to refill rather than reboil as you just got too much limescale otherwise, also tap water could not be used, unless you fancied a mug of gritty tea (limescale). I now live in Nottingham and it is fine to reboil the kettle, even using water out of the tap, I’ve been here over two years and not had to descale once! – there simply is none! At work we use an urn to fill our (very large) teapot and it tastes great. I think the taste of the tea is not down to whether you reboil water or not, it’s down to the tea you use. I always use yorkshire tea, simply – it’s the best. The pot has to be warmed before being filled with hot (not boiling) water for the tea and the milk added to the cup before the tea is poured – definately gives the best cuppa, and, been a very keen tea fan I’ve tried everything!
Fri 26 Jun 2009 at 12:16
I believe that the presence of oxygen does play a part in the taste of a good cuppa. After you’ve made a cup of tea try pouring it from one cup to another several times allowing the tea to fall as far as possible to aerate the brew. Compare the taste with a control sample not treated this way. The difference is surprising. I doubt if reboiling makes sufficient difference to the dissolved oxygen content to affect the tast; however, I have no data on this.
Fri 26 Jun 2009 at 12:17
I always renew the water because on re-boiling I can detect a taste somewhat similar to very dilute TCP. I can only attribute this to a reaction between any residual chlorine, from the water treatment process, and phenolic compounds leaching from the plastic of the kettle. If the water is used immediately on boiling then the contact time in the kettle is relatively short, but any water remaining hot in the kettle awaiting later re-boiling will obviously have a much longer contact time. The kettle has been changed several times always with the same result.
Fri 26 Jun 2009 at 12:34
Given that tea is an aroma, rather than a taste per se, it is possible that changes in surface tension have an impact. Also, do those with a heightened sense of smell more readily notice the difference or it is truly the taste of the water that’s changed?
Completely agree with Craig that you should only ever boil the amount of water required – saves water, energy and this heinous taste faux pas!
Fri 26 Jun 2009 at 12:39
Alison’s point are dubious. Most of the dissolved oxygen would be removed after the first boiling.
Fri 26 Jun 2009 at 12:54
The question seems to assume that you are making your tea by means of tea bags, in which case it will taste like dishwater however the water is heated. Use leaf tea and a teapot – and your second cupful is there, ready and waiting.
Whereas I am sceptical about most of the mumbo jumbo around teamaking, the water is certainly significant. As a student I moved between Chelmsford and Oxford. Both are hard water areas, but after each transit, tea had no flavour for a couple of weeks, until I acclimatised.
Fri 26 Jun 2009 at 13:32
In this politically correct era we live in, everybody should be attempting to minimise their carbon footprints by only boiling the required volume of water, thus eliminating the need to reboil any water and rendering this debate irrelevant
Fri 26 Jun 2009 at 13:49
Continuing boiling water will deposit the permanant hardness, Calcium Sulphate. This impossible to clean off using the removers designed for Calcium Carbonate, Hydrochloric acid is the only way.
Fri 26 Jun 2009 at 14:29
The reason why almost everyone prefer to refill the kettle than reboil some old water has indeed a scientific explanation.
It’s for the same reason why we’d rather swim in the sea or in a stream instead than in a pond.
Our survival instinct tells us that running water is safe while stagnant water is not. Indeed stagnant water is a nest of bacterias. It’s contaminated. Especially lest exposed to the light or the air.
The noise and the vision of fresh water running out of the tap reassure our instincts and make us feel good.
Our survival instinct which make us feel sick for exemple if we find a hair in our food because of that idea of contamination (even if the food would be perfectly aetable) or make us feel nauseating to drink from a glass of water that has been left on the kitchen table for many hours, also apply when it comes to reuse some boiled water from the kettle. Our conscience tells us it’s fine but our instincts push us to run some fresh water from the tap.
Fri 26 Jun 2009 at 15:02
As seen at http://water.usgs.gov/owq/FieldManual/Chapter6/table6.2_6.pdf the Solubility of oxygen in water (in mm Hg) at 760 mbar decreases from 9.1 at 20°C to 6.4 at only 40°. Thus it is a good guess that only minute amounts of oxygen will be present in boiling water or water near the boiling point.
Experiments to be performed:
1) bubble either air, oxygen or nitrogen through tee while being prepared and measure at least simple items like colour.
2) measure some markers (e.g. theine content) or by HPLC after making tea using water of different temperatures.
3) do the same by varying the time before the leaves are sieved off
4) use tea experts to taste teas prepared differently and let them assess the ourcome
Fri 26 Jun 2009 at 15:42
Chemistry? You want chemistry? We got chemistry. Depending on the natural groundwater in the area of the country you live in, your water supply may contain bromide. Drinking water is chlorinated to keep it safe. The plastic in the kettle you boil the water in may leach truly minute amounts of phenols, or indeed they may arrive there from rubber tap washers or other domestic plumbing. Provide the magic combination of ingredients in the right proportions and enough time and bingo – you get chlorinated and brominated phenols which taste nasty in tea at parts per trillion levels – equal to a drop in 26 Olympic swimming pools. Not a lot. Reboiling the water makes it more likely that this will happen. Of course, if you haven’t got bromine in the water, or you have a better class of tap washer, or you drink coffee (which disguises the taste entirely) – then go ahead, save water and reboil it.
Fri 26 Jun 2009 at 16:57
In this day and age boiling fresh water, when a reboil is quicker and more energy smart, is wasteful.
Since the majority of kettles have limescale filters on/near the spout a good clearing now and again removes the concern for build up.
Also, using bottled water in a kettle makes little or no difference to the taste.
Fri 26 Jun 2009 at 18:15
Surely, any chemist would know that if you are diluting a colloid, you always had the continuous phase to the disperse phase, ie you add the tea to the milk and not vice versa?
As far as re-boiling the water is concerned, surely the calcium hydrogencarbonate will largely have decomposed by the time the water reaches boiling the boiling point, so re-boiling will not significantly affect the concentration of calcium and hydrogencarbonate ions and hence the flavour. My kettle has a fine mesh to prevent particles of precipitated limescale entering the teapot or cup.
Hard water may also contain, for example, calcium sulfate. This will remain in solution and if you allow the water to boil for a long time the concentration will gradually increase. However, an automatic kettle will cut off before significant amounts of water evaporate. So this will have a negligible effect.
The only explanation which makes any sense is that dissolved oxygen escapes on boiling and is not available to react with essential oils in the tea leaves. However, whether anyone other than an official tea-taster has a sufficiently sensitive palate to tell the difference is another matter. Personally, I prefer to save both water and energy and re-boil.
Sat 27 Jun 2009 at 07:02
Tea is anatural product and contains -in additon to caffiene about 400 different organic compounds. Some of these are soluble in water and end up in the infusion from steeping tea leaves in water for about 3 – 5 minutes. These include valuable antioxidants which prevent aging. Some of the important organic compounds containg carboxylic acid groups can be rendered insoluble by calcium ions and therefore tea should always be brewed in soft or distilled or deionised water. This is why the same brand of tea can taste very different in different regions of the UK. For a perfect cup of tea one should use freshly boiled deionised water and then the taste and health benefits of the tea will not be affected by the ionic content i.e. calcium ions etc in the water. Tea is a very special beverage and should always be prepared and drunk with due reverence and ceremony.
Sat 27 Jun 2009 at 07:30
Surely a more important point is whether the cup of tea is made with loose tea or tea bags. If loose tea is used, then a tea cosy is used on the pot and a tea strainer is used. My father always claimed he could tell the difference between a cup made with loose tea and a tea bag, but on the other hand, my mother in law can make any cup of tea taste awful.
Sat 27 Jun 2009 at 07:52
Years ago BBC’s Jilly Goulden advocated running the tap for two minutes in the morning to get,’fresh water for tea’! Shame on her!
I suggest: Pour out residual boiled water into a watering can for house & patio plants and the steam iron ; rinse out the kettle ; fill the kettle to meet cup or teapot needs plus 10% to minimise energy use.
Everybody wins!
Sat 27 Jun 2009 at 09:39
Regarding the many comments about oxygen loss from the water, is it also possible that water that has stood for a while exposed to the air with a large surface area (as with most kettles) actually contains more oxygen than that straight from a tap? My tongue-in-cheek counter hypothesis, in the absence of any evidence, is that any change in taste could be due to inceased oxygen content of the water. Or perhaps the taste depends on the position of your tongue?
Sat 27 Jun 2009 at 22:36
As an American reading this in South Carolinia I can tell you we simply drink coffee but if my wife ever washed the pot I would ship her to Londaon.
Sun 28 Jun 2009 at 09:27
I made tea in the UK in a totally indiscriminate way: fresh and re-boiled water, milk with and without the tea bag in the cup, milk in my Earl Grey… Any kind of anathema that could possibly be perpetrated, was. I never tasted any difference between two cups made from the same water. But I could tell a cup made in West Yorkshire from one in Cambridgeshire without a problem.
I agree with Ian Smith about some people needing their ritual in order to enjoy they tea, and with Girdharilal and Isabelle that you should never boil the water to make tea!
Regarding hygiene, that is a moot point, first from the fact that there isn’t such a large inlet for germs in modern kettles, and second because any air-borne micro-organism that resists boiling and being swallowed and remains infectious ha
Sun 28 Jun 2009 at 09:27
… has a right to live!
Sun 28 Jun 2009 at 10:46
I haven’t notice much difference between re-boiled and fresh water – there is probably only a difference if you are drinking the fine teas such as darjeeling. However, I respect the right answer is as follows:
We should only boil the amount of water we actually need – boiling a larger quantity of water uses more energy and we are regularly being told by politicians and green organisations that we must cut energy use for the good of the environment etc. Of course if we only boil the right amount we will have to refill every time.
Mon 29 Jun 2009 at 12:08
We use a “One-Cup” water boiler, so the question is meaningless, and as it only boils one cup (~250 ml) at a time, and very quickly I must add, the boiling step is economical too…
Mon 29 Jun 2009 at 12:34
Having moved to one of the countries worst areas for hard water not only is it necessary to use fresh water, but it must be filtered as well.
I have my very own personal filtered water analyser which is far more sensitive and effective than the conductivity devices fitted to stand alone water filters – it is my partner. He warns me far in advance of the indicator on top of the filter when the cartridge needs changing.
I just need some help in calibration. I need at least two settings:
1) It’s not really that bad.
2) OK, you’re right, I’ll change the cartridge.
Maybe with some work he could be applied to judge different areas water and recommend if people should reboil or refill.
Mon 29 Jun 2009 at 12:45
I heard a lecture a few years ago about plasticisers leaching from plastic kettles – obvious when you think about steam distillation. At the time I had young children and I have seen too many skin grafts following scalds, so I always tipped away the hot water after use. Now I have a bottom-heated kettle and only boil as much as I need.
Calcium in the water (and the milk) makes an unsightly scum on the surface of the tea which stains the cups. Does anyone have an answer to that?
Mon 29 Jun 2009 at 14:02
There is a philosophical problem with the implied approach to this problem. The correct question should not be is there a chemical explanation to explain why fresh water should be used? but does using fresh water give a perceptible difference in taste? I can assure you it does to me and to most regular tea drinkers.
I have never forgotten in my student days when I had to make tea for a group of British working men. Their initial response could be paraphrased as “This tea is not of the substance and quality demanded” The expressions used as I remember were a series of comments on my personal habits and antecedents!
If we accept the experimental evidence it is proper to try and seek a chemical explanation. The likely chemical explanations can be divided into two classes namely loss of substances on boiling and gain of substances on standing.
The likely candidates for loss on boiling are oxygen and carbonates. The oxygen will interact with the tea oils in the tea while the carbonates will affet the extraction of flavour.
In the gains on standing category are lime scale and trace metals from the kettle. Soft acidic water is more likely to pick up trace metals. Even plastic kettles have metal elements.
This question reminds me of several incidents in the food industry where the management changed the process and did not understand it altering the product. The consumer noticed the difference and stopped buying it.
It has to be remembered that chemistry is an experimental science. It is entirely satisfactory to build theories around experiments but not to discard experiments because of theories
Tue 30 Jun 2009 at 09:20
Nothing tastes quite so sweet as a penny saved so re-boiling the already warm water has my vote.
Tue 30 Jun 2009 at 13:55
Having brewed tea for the best part of 50 years and usually credited with producing a good cuppa, my main conclusion is that the quality of the water outweighs all other factors including boiled and reboiled water. This is based on brewing tea, usually loose leaves of PG Tips , over several years in Newcastle, Maidenhead, Doncaster, Malvern, Brownsville (TX USA), Mexico City and a few other less regular places. I cannot define what I mean by the “quality” of the water but nothing else seems to matter as much to the taste.
Currently I am using Severn Trent water which is filtered through a Brita filter and I use the colour of the tea as a measure of when the filter needs changed. With a new filter the tea is much lighter in colour getting darker as the filter is exhausted. Not sure if the filter is removing or adding something to account for the colour variation.
Incidentally I gave up on ceramic teapots many years ago and now use stainless steel which I never prewarm but I do keep it clean, no brown tannin stains.
Wed 8 Jul 2009 at 11:08
I know I missed the deadline, but just wanted to say that I never reboil water because it tastes disgusting. Maybe I am more sensitive to the taste than other people. Leave boiled water in a kettle for more than 15 minutes and I can guarantee I can taste it. Consequently I only put in the amount of water I need. Unfortunately this means that usually I have to boil water just below the minimum line in order not to waste hot water. Why is it so hard to find a kettle that only boils one cup?
Thu 9 Jul 2009 at 22:43
Even in a very hard water area such as here in Wiltshire, you can consistently make a good cup of tea with ordinary unfiltered tap water if you pay attention to the most important factor — scrupulous removal of all fluffy loosely adhering limescale in your kettle from previous boilings. Make sure your brush has a good big flat end to clean the base and sides of your bottom-boiling kettle every time you make your tea BEFORE you boil the kettle. It takes about 30 seconds and uses about a third of a cup of cold water for rinsing. (Even this little can be saved for watering the plants if you are that much of an environmental puritan.) No need for water filters, pesky little plastic spout inserts that fall out and become mis-shapen so they won’t fit back or even chemical lime scale removers and a delicious cuppa every time. If you are too lazy to do this, expect the disgusting bicarb tasting brew you deserve. As for energy saving overall, your kettle will last far longer and work more efficiently; your nerves and digestion are in for a treat as well.
Science? It could not be simpler. Tough limescale only adheres strongly to the inside of the kettle after several boilings. If you do not brush, you will get enough fluffy suspended lime-scale carrying over into your pot or mug every time you brew to seriously affect the taste.
Reboil or draw fresh? If you live in a soft water area, it matters little. If you live with hard water, and your kettle was clean from last time, the amount of fluffy suspended lime-scale made by one boiling will probably be insufficient to make a diference to all but the most fastidious, so a reboil will not be a disaster.
Want a good cuppa and to be an eco-god/godess? Buy a brush. It’s brilliant.
Mon 20 Jul 2009 at 12:51
RSC
There are several factors here which mean there is no universally correct answer:
1. The area you live in and hence quality of water. In southern England the solids content in water can be as much as 2-3%, where here in central Scotland, its generally < 0.02%, a 100 fold difference! If you live in a much harder water area, you've a much higher chance of buiding up the hardness of the water after consequtive boils if you dont rinse out the kettle.
Tip: Adding around 20 ml of common cheap vinegar to around 100 ml of water in the bottom of your kettle overnight occasionally is a very cheap and effective way of staying scale free. You dont need to splash out on more expensive products but remember to rinse the kettle in the morning!
2. How full you fill the kettle is also key. You should really only boil the water you need. for instance for one cup of tea, pour one cup of water in the kettle, then you'll empty the kettle and avoid build up of concentated deposits which are bound to effect taste. Here we have a solution which is also important environmentally. If we all got used to boiling only what we need it would actually have a measurable effect on reducing the nations energy need and ensure the best tasteing tea!
Best regards, Walter