Troubleshooting

The main list is alphabetical by the complaint rather than grouped by cause, because the cause is not what a reader knows on arrival — working out which one you have is what these pages are for, and the label beside each entry says where it usually leads. If you already know, start from the cause index below instead.

• Every infusion in my gongfu session tastes the same

  Usually leaf quantity5 likely causes

  The cups are pleasant and interchangeable, with none of the change from steep to steep the method is supposed to show.

  Showing a tea change across a session is the entire argument for gongfu brewing, and a flat session usually means the setup has quietly become western brewing with extra washing-up. Three parameters account for nearly all of it.

• I bought a big bag to save money and it was stale before I finished it

  Usually storage5 likely causes

  A large quantity bought at a good unit price faded well before it was drunk, so the saving turned into waste.

  The unit price falls with quantity and the rate of deterioration does not, so beyond a certain size the cheaper tea costs more per drinkable cup. Which size that is depends almost entirely on category, and green tea and black tea sit at opposite ends of it.

• I bought a water filter for my tea and it changed nothing

  Usually water chemistry4 likely causes

  A filter jug or tap filter was bought specifically to improve the tea, and the cup tastes the same as it did before — with the same dullness, the same film and the same scale in the kettle.

  Domestic filters are effective at what they are built for and mostly do not do the thing tea drinkers buy them for. A carbon filter is designed to remove chlorine, taste, odour and some metals; hardness — the dissolved calcium and magnesium that flattens aroma and produces the surface film — is a different problem needing a different mechanism. So a reader whose complaint was chlorine gets a clear improvement, and a reader whose complaint was hard water gets almost none, from the same product.

• I cannot taste the difference between my expensive tea and my cheap one

  Usually technique6 likely causes

  Two teas at very different prices taste much the same in the cup, and the tasting notes on both packets describe things you cannot find.

  Sometimes this is a real observation about the teas and sometimes it is an artefact of how they were tasted. Working through it in order is worthwhile, because the answer is occasionally that the expensive tea is not worth the money and more often that the comparison was never set up to show a difference.

• I filtered my water and the tea got worse

  Usually water chemistry4 likely causes

  After switching to filtered, distilled or reverse-osmosis water the tea is cleaner and emptier — no off-notes, and no body either. It tastes thin and slightly hollow.

  Filtering is usually an improvement and it can be taken too far. Tea needs some dissolved mineral to extract properly and to carry body; water stripped of everything produces a clean, characterless cup, and this is the one water problem that gets worse the harder you work at it.

• I have too many teas open and most of them are going stale

  Usually storage5 likely causes

  A dozen or more packets are open at once, three or four get drunk regularly, and the rest fade quietly on the shelf until they are thrown away.

  This is an arithmetic problem rather than a storage one, and it is worth separating from the bulk-buying fault it resembles. There the mistake is one packet that is too big; here every packet is a sensible size and there are simply more open at once than the drinking rate can clear. Better containers do not help, because nothing is wrong with the containers — what is wrong is the ratio between how fast tea is opened and how fast it is drunk.

• I think the famous tea I bought is not what it claims to be

  Usually leaf quality5 likely causes

  A tea sold under a protected or famous place name — West Lake Longjing, Tongmu Zheng Shan Xiao Zhong, a named pu-erh village, Anxi Tie Guan Yin — does not match its descriptions, and the price was suspiciously reasonable.

  The honest starting position is that you cannot verify a place-name claim after purchase without laboratory access, and nobody selling you a verification service can either. What you can do is establish whether the tea is consistent with the claim, and understand the arithmetic that makes most such claims false — which is more useful than a verdict on your particular packet.

• Leaves stick to the cup, the pot and my teeth

  Usually technique4 likely causes

  Fine leaf clings to the inside of the vessel, comes through into the cup, and ends up in the last mouthful.

  Usually a mismatch between leaf grade and filtration, and occasionally a sign that the leaf is more broken than it should be. Grandpa-style brewing has its own version of this and its own answer.

• My bamboo whisk is losing tines

  Usually technique5 likely causes

  Fine bamboo tines snap off during whisking and turn up in the bowl, and the whisk feels stiff and splayed.

  A chasen is a consumable rather than an heirloom, so some loss is expected. What is not expected is losing tines within weeks, and that is almost always how it is being handled and dried.

• My chai catches on the pan or boils over

  Usually technique5 likely causes

  A scorched note runs through the finished drink, or the pan foams over the moment your back is turned.

  Both problems come from the same step — bringing milk to the boil — and both are handled by the order in which things go into the pan and by staying with it. There is no single authoritative recipe, but the sequence is fairly consistent across households.

• My chai is harsh and drying rather than rich

  Usually agitation5 likely causes

  The drink is strong enough but unpleasant with it: a rough, drying grip on the tongue and a flat cooked note, rather than the round sweetness a good chai has.

  This is the opposite fault from thin chai and it has a different cause. What is wrong here is usually not bitterness from over-extraction but astringency from boiling the leaf hard for too long, and the two want opposite corrections — shortening the boil rather than adding leaf.

• My chai tastes of hot spiced milk rather than tea

  Usually technique6 likely causes

  The drink is pleasant and sweet and the tea is nowhere in it — no colour to speak of, no briskness, and nothing that would tell you tea had been involved.

  Chai is a decoction, and it is built to be strong enough to survive milk, sugar and spice. Almost every thin chai comes from one of three things: not enough leaf, the wrong leaf, or milk added too early and in too high a proportion for the tea to compete with.

• My clay pot has changed how the tea tastes

  Usually equipment5 likely causes

  A tea that tasted right in porcelain comes out muted, differently scented, or carrying something that was not in the leaf.

  This is the clay doing exactly what it is for, and whether it is a fault depends entirely on what the pot was used for previously. Unglazed clay is porous: it absorbs a trace of every session and gives some of it back.

• My cold brew tastes like faintly flavoured water

  Usually leaf quantity5 likely causes

  After a night in the fridge the jug is pale and tastes of very little, with none of the sweetness cold brewing is supposed to give.

  Cold brewing is forgiving on time and unforgiving on the two things people get wrong: how much leaf went in, and whether the tea was suited to the method at all. Extending the steep is the instinctive fix and does the least.

• My first infusion is always the worst one

  Usually leaf quality5 likely causes

  The opening cup is thin, dusty or flat, and the second is markedly better — consistently, across different teas.

  For a large class of teas this is expected behaviour rather than a fault. Compressed, tightly rolled and heavily roasted leaf has not opened by the end of the first steep, and the first infusion is doing the work of wetting rather than of extraction.

• My gaiwan is too hot to hold

  Usually technique5 likely causes

  The rim and lid become uncomfortable within seconds, the pour is rushed, and tea ends up on the tray.

  Almost entirely a fill-level and grip problem rather than a vessel problem, and the fixes are free. A gaiwan is designed so that a dry rim stays holdable; filling it to the brim removes that design.

• My gongfu brewing falls apart when I have guests

  Usually equipment5 likely causes

  Sessions that work perfectly alone become chaotic with three or four people: the tea is inconsistent, the pours are rushed, and the cups arrive at different strengths and temperatures.

  Gongfu is designed around a small vessel and a fast decant, and both properties become harder as the number of drinkers rises. Scaling it is a matter of changing the equipment and the sequence rather than of brewing faster.

• My gongfu tea is bitter even at five seconds

  Usually over-extraction5 likely causes

  The timer says five or ten seconds and the cup is over-extracted anyway, with the later infusions dropping off sharply.

  The steep does not end when the timer stops; it ends when the vessel is empty. If pouring off takes fifteen seconds, a five-second infusion was a twenty-second infusion, and every correction made to the timer is being applied to the wrong number.

• My green tea goes yellow or brown in the cup

  Usually technique5 likely causes

  The liquor is green when poured and turns yellow, olive or brownish within minutes, sometimes with a darker rim.

  Some of this is normal and unavoidable, and some of it points at water and temperature. Separating the two matters, because the normal version is not worth chasing and the water version is a genuine and fixable fault.

• My green tea tastes bitter

  Usually over-extraction6 likely causes

  The cup is sharp and unpleasant, sometimes with a drying, mouth-puckering quality alongside the bitterness.

  Almost always water that is too hot, and almost never the tea’s fault. Work through the causes in order — the first one accounts for most cases.

• My green tea tastes flat and looks dark in this house

  Usually water chemistry5 likely causes

  A delicate green tea that tasted bright elsewhere comes out dull and heavy here, with a darker, browner liquor than it should have and none of its aroma.

  This is a water composition problem rather than a contamination one, and it is distinct from scale in the kettle: the water can be perfectly clean and still be wrong for the leaf. Hard water shifts the colour of the liquor and suppresses aroma, and delicate green, white and yellow teas show it first.

• My gyokuro tastes like an expensive sencha

  Usually temperature5 likely causes

  A costly shaded tea gives a cup that is pleasant, green and unremarkable, with none of the thick sweetness and savoury depth it was bought for.

  Gyokuro is not a better sencha to be brewed the same way; it is a tea whose entire character only appears under a specific set of parameters. Brewed at sencha temperature in sencha proportions it becomes a good ordinary green tea, which is a waste rather than a fault.

• My iced tea has gone cloudy

  Usually technique3 likely causes

  Tea that was clear when hot turns hazy or milky once chilled.

  A physical effect rather than a fault: certain compounds come out of solution as the tea cools slowly. It affects appearance far more than flavour, and it is straightforward to avoid.

• My iced tea tastes watery once the ice melts

  Usually technique4 likely causes

  The tea is good for the first mouthful and thin by the bottom of the glass.

  Flash-chilled iced tea is brewed to be diluted, and the arithmetic is the whole method. Brewing at normal strength and pouring it over ice produces exactly this, and no amount of longer steeping compensates for the wrong ratio.

• My Japanese green tea comes out cloudy

  Usually leaf quality4 likely causes

  The liquor is opaque and deep green rather than clear, with fine particles suspended through it and a layer settling in the bottom of the cup.

  In most cases this is the tea doing exactly what it was made to do. Deep-steamed sencha breaks down into fine particles during processing, and those particles are the source of its colour, its thickness and much of its flavour — they are not sediment and not a fault.

• My Japanese green tea tastes of seaweed or fish

  Usually leaf quality5 likely causes

  A sencha, gyokuro or matcha reads as marine — seaweed at best, distinctly fishy at worst — and it is not clear whether that is the tea or a fault.

  The marine descriptor is genuine and intended in steamed Japanese green tea, and it is also what a stale one smells of. The two are distinguishable, and the distinguishing feature is whether the note is sweet and clean underneath or sits on its own with nothing behind it.

• My leaf floats on top and will not sink

  Usually leaf quality5 likely causes

  Dry leaf sits on the surface in a dry-looking raft, and the tea underneath is pale long after it should have been ready.

  Floating leaf is not brewing leaf. Whatever is on the surface is only partly wetted, so the effective dose is lower than the dose you weighed, and the result is a weak cup that a longer steep only partly rescues.

• My matcha foams and then the foam collapses

  Usually equipment6 likely causes

  A good head of foam forms during whisking and has largely disappeared by the time the bowl reaches the table, leaving a flat surface with a ring of bubbles round the edge.

  This is a different problem from matcha that will not foam at all. The foam formed, so the powder was suspended and the whisking worked; what failed was the foam’s stability, and that is governed by bubble size, water temperature and how much powder is holding the structure up.

• My matcha is harsh and I think it is a cooking grade

  Usually leaf quality5 likely causes

  A matcha bought to drink is dull-coloured, gritty and aggressively bitter, and the tin says culinary, cooking or ingredient grade — or says nothing at all.

  Grade words on matcha are not defined by anybody. Ceremonial, premium and culinary are marketing terms with no standard behind them, so the same word means different things between two brands. What is real is what the terms are gesturing at, and those are observable properties you can check on the tin in front of you.

• My matcha is lumpy, gritty or will not foam

  Usually technique4 likely causes

  Undissolved lumps float on the surface, powder settles at the bottom, and no fine foam forms.

  Matcha is suspended rather than dissolved, so anything that stops the powder dispersing shows immediately. Almost all of it is technique and vessel rather than the powder itself.

• My matcha latte is lumpy and the powder sinks

  Usually technique5 likely causes

  Whisked straight into milk, the matcha forms lumps that will not break up, and within a minute a green layer has settled at the bottom of the glass.

  Matcha is a suspension, not a solution, and it has to be suspended before the milk arrives. Whisking powder directly into cold or hot milk skips the step that makes the drink work, and no amount of extra whisking afterwards recovers it.

• My matcha powder has gone dull green or khaki

  Usually storage5 likely causes

  The powder that was vivid green when the tin was opened is now olive, khaki or faintly brown, and the bowl looks muddy rather than bright.

  Colour is the one quality signal in matcha a drinker can read directly, and it fades faster than in any other tea because milling has exposed an enormous surface area to air and light. The fading is not reversible, so every cause below is really a question about storage from the moment the tin was opened.

• My matcha tastes harshly bitter

  Usually temperature5 likely causes

  The bowl is sharp and drying rather than sweet and thick, and the bitterness stays after the drink is gone.

  Matcha has no strainer and no timer, so there is nothing to adjust after the fact — everything in the powder ends up in the bowl. That makes it the least forgiving preparation in tea, and it narrows the causes to water temperature, dose and grade.

• My matcha will not mix into cold water

  Usually technique4 likely causes

  Whisked straight into cold water or ice, the powder stays in lumps, floats in rafts on the surface and sinks in clumps to the bottom.

  Matcha is a suspension rather than a solution — nothing dissolves at any temperature — and cold water makes the wetting step much harder without changing anything else. The fix is entirely about the order of operations, and it costs about fifteen seconds.

• My milk curdles or separates in the tea

  Usually technique5 likely causes

  Flecks or threads appear when the milk goes in, or the surface breaks into small islands, and the drink looks grainy rather than smooth.

  Milk separates in tea for reasons that are mechanical and chemical rather than a sign that anything has gone off. Heat, acidity and the order things are added all destabilise milk protein, and each has a different fix.

• My pu-erh cake will not break apart cleanly

  Usually technique5 likely causes

  The cake resists the pick, then gives way suddenly into powder and fragments rather than intact leaf.

  Almost always tool and technique rather than the cake. Shredded leaf brews bitter and unevenly, so how the cake comes apart determines how it tastes — which makes this a flavour problem wearing a practical disguise.

• My pu-erh or dark tea tastes sour

  Usually leaf quality5 likely causes

  A sharp, tart, almost vinegary note runs through a ripe pu-erh, a sheng or another dark tea where the description promised earthy sweetness.

  Sourness is the single most informative fault in dark tea, because it is the one that distinguishes a brewing problem from a storage problem from a manufacturing problem. In some teas it is intended and correct; in this category it almost never is, and where it comes from decides whether the tea is recoverable.

• My pu-erh tastes exactly the same as when I bought it

  Usually storage5 likely causes

  A cake bought several years ago to age has not noticeably changed, and it was stored carefully.

  Almost always the care is the problem. Storage advice for tea is written for categories that must not change, and applying it to the one category that is supposed to change stops the process it was bought for. Ageing is microbial and enzymatic work that needs moisture, air and time, and the standard airtight-opaque-cool instruction removes two of the three.

• My refrigerated tea has gone damp and lost its aroma

  Usually storage5 likely causes

  Tea kept cold has become soft or slightly clumped, smells muted, and tastes flat and papery within weeks of being put away to protect it.

  Refrigerating tea is sound practice and it fails in one specific way: opening a cold container in a warm kitchen condenses moisture onto the leaf. The leaf reabsorbs water, and reabsorbed water accelerates every kind of staling, so a storage method chosen to preserve the tea ends up degrading it.

• My roasted oolong tastes only of burnt toast

  Usually leaf quality5 likely causes

  Char and ash dominate, and none of the fruit, mineral or floral character the tea was described as having comes through.

  Three quite different situations produce the same cup: a tea that has not rested since firing, a tea roasted too hard, and a tea brewed in a way that pushes the roast forward. The first resolves itself with time and the second does not.

• My rolled oolong tastes of almost nothing

  Usually under-extraction4 likely causes

  A tightly rolled oolong gives a pale, thin first cup, and the pellets are still mostly closed afterwards.

  Ball-rolled oolong needs a long first steep simply to begin opening. Applying a delicate-tea timing to it produces a cup made from the outside of the pellets only.

• My second infusion is much worse than the first

  Usually technique4 likely causes

  The first steep is good and the second is bitter, flat or both.

  Usually the leaf was left sitting in water between steeps, or the second infusion was given the same time as the first. Both are easy to fix and neither is the tea’s fault.

• My second infusion is thin and watery

  Usually under-extraction5 likely causes

  The first cup is good and the second has body but no flavour, or no body at all — thin rather than bitter.

  A different fault from a bitter second steep and with the opposite fix. Thin means too little was left in the leaf or too little was asked of it, and the commonest cause is that the first steep was long enough to take nearly everything.

• My shou pu-erh tastes fishy or muddy

  Usually leaf quality4 likely causes

  A ripe pu-erh has a pond-like, fishy or muddy note that overwhelms everything else.

  Usually a young wet-piled tea that has not been rested, and usually a rinse that was skipped. Both are recoverable, and the tea often improves substantially with time in the cupboard.

• My tea arrived broken, with dust at the bottom of the packet

  Usually leaf quality5 likely causes

  Whole-leaf tea bought at a whole-leaf price contains a lot of fragments, and there is fine material in the bottom of the bag.

  Some breakage is unavoidable and some is a fault, and the distinction is proportion and where in the packet it sits. It also matters practically rather than only commercially: broken leaf extracts faster than whole leaf, so a packet with a large fine fraction needs shorter steeps than the same tea nominally deserves.

• My tea came out too strong — can I just add water?

  Usually leaf quantity5 likely causes

  A cup or pot is far stronger than intended, and the obvious response is to dilute it.

  Diluting works for one of the two things that make tea too strong and not for the other, which is why it sometimes rescues a cup completely and sometimes produces weak, harsh tea. Concentration can be undone with water. Over-extraction cannot, because dilution lowers everything proportionally and the harsh fraction is already in the liquor.

• My tea disappears when I add milk

  Usually leaf quality4 likely causes

  A tea that tasted fine on its own becomes a pale, vaguely sweet milk drink with no tea character left in it.

  Milk mutes aroma and adds body, so a tea that survives it has to bring strength and briskness rather than fragrance. Most of the teas people are told to try are the opposite of that by design.

• My tea gets drier and harsher as it cools

  Usually technique5 likely causes

  The first mouthful is balanced and the last one, several minutes later, grips the tongue and feels rough — from the same cup, with nothing added.

  Nothing is extracting; the cup is closed. What changes is perception: astringency becomes more noticeable as tea cools, while the volatile aromatics that were balancing it have evaporated. This is astringency rather than bitterness, and the fixes are the astringency ones.

• My tea goes cold before I finish it

  Usually technique5 likely causes

  The cup is lukewarm within a few minutes, and in a gongfu session the later infusions arrive noticeably cooler than the early ones.

  Heat leaves through the vessel, the surface and the air, and small thin vessels lose it fastest. This matters beyond comfort: roasted and dark teas need sustained temperature to open, so a cooling vessel under-extracts as well as disappointing.

• My tea goes damp within weeks and I live somewhere humid

  Usually storage5 likely causes

  Leaf that arrived loose and crisp becomes soft, slightly clumped and quiet within a few weeks, and the aroma flattens long before any best-before date is close.

  Almost all tea storage advice is written for temperate kitchens, where the ambient air is dry enough that a reasonable container is enough. Where the air is permanently humid it is not, because the problem is no longer keeping moisture out of the container — it is that moisture came in with the leaf, or entered every time the container was opened, and then had nowhere to go. The fix is a different routine rather than a better tin.

• My tea is drying and puckering rather than bitter

  Usually leaf quality4 likely causes

  The tea makes the mouth feel dry and rough, gripping the tongue and cheeks, without necessarily tasting bitter.

  Astringency is a tactile sensation, not a taste, and it has different causes from bitterness. Advice that runs the two together fixes one and leaves the other, which is why this has its own page.

• My tea is harsh and I cannot tell whether it is bitter or astringent

  Usually leaf quality4 likely causes

  The cup is unpleasant in a way that is hard to name, and every piece of advice about it assumes you already know which of the two words applies.

  Bitterness is a taste and astringency is a physical sensation, and they arrive from different compounds by different routes. Almost all consumer tea writing runs them together, which is why the same advice — cooler water, shorter steep — is offered for both and only helps one. Establish which you have before changing anything, because the two faults are fixed in opposite directions.

• My tea is past the date on the packet

  Usually leaf quality5 likely causes

  A packet carries a best-before date that has passed, and it is not obvious whether that means anything.

  The date on a tea packet is a quality date rather than a safety one, and it was set for a sealed packet in a warehouse rather than for yours. What actually matters is which category it is, whether it has been opened, and how it has been kept since — and for one whole category the date is meaningless in the opposite direction, because the tea is meant to keep changing.

• My tea is weak since I moved somewhere high

  Usually temperature4 likely causes

  The same tea, the same dose and the same timer produce a thin, under-developed cup, and the water is boiling — visibly and vigorously — before it goes in.

  Water boils at a lower temperature as altitude rises, so ‘boiling’ stops meaning 100 °C. At 2,000 metres it is roughly 93 °C and at 3,000 roughly 90 °C, which is a real difference for black tea, dark tea and roasted oolong, and no amount of longer boiling raises it.

• My tea smells medicinal, antiseptic or minty

  Usually leaf quality4 likely causes

  A sharp cooling note that reads as wintergreen, germoline, mouthwash or antiseptic sits over the aroma — usually in the dry leaf as well as the cup, and usually in a good tea rather than a cheap one.

  This is the fault that most often is not one. The note is a real and specific aromatic character found in some Darjeeling and some high-grown teas, and it is a recognised part of their profile rather than contamination. It is unsettling because English has no flattering word for it — every available description borrows from a first-aid cabinet — so a drinker meeting it assumes something is wrong. Ruling out the two things that genuinely would be wrong takes one brew.

• My tea smells musty or damp

  Usually storage3 likely causes

  The dry leaf smells of damp cardboard, cellar or mildew rather than of tea.

  Almost always moisture. The important distinction is between a stored dark tea developing an expected earthy character and any tea that has actually taken on damp — the first is normal and the second is not worth drinking.

• My tea tastes flat and I reboiled the kettle

  Usually water chemistry4 likely causes

  A cup made from water that had already been boiled once tastes dull, and the internet is confident that this is why.

  This is a rare troubleshooting entry where the honest answer is that the thing you suspect is probably not the cause. Reboiling does change the water slightly and the change is small; three other things that happen at the same moment are much larger, and chasing the reboil means not fixing them.

• My tea tastes flat and lifeless

  Usually storage4 likely causes

  The tea is not bitter or weak exactly, but has lost its aroma and tastes dull and papery.

  Usually storage rather than brewing. Tea fades rather than spoiling, and it loses aroma and sweetness before it loses astringency — which is why stale tea reads as flat and slightly harsh at the same time.

• My tea tastes of chlorine, metal or the kettle

  Usually equipment5 likely causes

  A chemical, swimming-pool or metallic note sits over the tea, and it is there whichever tea is brewed.

  If every tea tastes the same way, the leaf is not the variable. Tea is roughly 99 per cent water by weight, so anything in the water arrives in the cup at full strength — and a kettle used for other things arrives with it.

• My tea tastes of the cupboard it was kept in

  Usually storage5 likely causes

  The dry leaf carries a note that does not belong to it — spice, coffee, cleaning products, or simply a generalised kitchen smell — and the same note comes through in the cup.

  Tea is an excellent adsorbent, which is the property jasmine scenting exploits deliberately. Left in anything that is not airtight, leaf takes up whatever the surrounding air carries, and the vector here is ambient odour rather than a container that previously held another tea.

• My tea tastes soapy or perfumed

  Usually equipment5 likely causes

  A soapy, floral or cosmetic quality sits over the tea and does not belong to it.

  Two very different causes produce nearly the same impression: detergent residue somewhere in the chain, or a genuinely floral tea meeting a palate that reads intense florals as soap. Ruling out the first takes one brew.

• My tea tastes sour or acidic

  Usually leaf quality5 likely causes

  A tart, sharp or faintly vinegary edge sits in the cup — closer to lemon or to wine than to the bitterness or dryness tea is usually criticised for.

  Sourness is a taste, and it is a different taste from both of the faults tea writing usually discusses. Bitterness comes from catechins and caffeine and is driven by temperature and time; astringency is not a taste at all but the drying grip of polyphenols binding saliva proteins. Sourness is acid, and every cup of tea has some — tea liquor is mildly acidic by nature. It becomes a fault only when something has raised it, and the four things that raise it are different enough that the cause decides whether the tea is recoverable.

• My tea tastes weak or watery

  Usually leaf quantity4 likely causes

  The cup is thin and has little flavour, however long it is left to steep.

  Almost always too little leaf, or leaf with nowhere to expand. Steeping longer is the instinctive response and makes the cup astringent rather than stronger, because the harsh fraction keeps extracting after the pleasant one has finished.

• My teapot came out of the dishwasher damaged or tasting wrong

  Usually equipment5 likely causes

  A pot or cup returns from a dishwasher cycle dulled, with faded decoration, a fine web of surface cracks, or a persistent taste that was not there before.

  A dishwasher combines three things teaware handles badly: strongly alkaline detergent, sustained high temperature, and a long wet cycle followed by heated drying. Glazed porcelain without decoration generally survives all three; almost every other kind of teaware fails on at least one, and two of the failures cannot be undone. The useful move is one rule per material rather than one rule for the cupboard.

• My teapot spout dribbles down the side

  Usually technique4 likely causes

  Tea runs back along the underside of the spout and onto the table instead of leaving cleanly.

  A pouring fault with three common causes, one of which is a genuine design defect and two of which are not. Working out which you have takes one pour of plain water.

• My tin smells of the tea that was in it before

  Usually storage4 likely causes

  A caddy or jar carries the aroma of its previous contents, and the new tea starts to taste of it within days.

  Tea absorbs aroma readily — the same property that makes jasmine scenting possible works against you in a cupboard, and it works in both directions. Washing the tin is the instinctive fix and usually the wrong one.

• My vacuum-packed tea faded quickly once I opened it

  Usually storage4 likely causes

  A brick-hard vacuum block or a taut foil packet was excellent on opening and noticeably flat within weeks, despite being resealed carefully — or the packet arrived puffed up rather than tight, which looked like a fault.

  Commercial packing excludes oxygen, either by pulling a vacuum or by flushing the packet with an inert gas. Both work extremely well and neither can be re-created at home, so opening the packet is a much larger event than it looks: it ends the preservation method rather than interrupting it. The date on the packet was set for the sealed state and stops describing the tea the moment the seal is broken.

• My water is not the temperature the kettle says

  Usually equipment5 likely causes

  The kettle is set to 80 °C and the tea behaves as though it were much hotter or much cooler, and the same setting gives different results on different days.

  The number on a kettle describes the water in the kettle at the moment it stopped heating, and several degrees are routinely lost between there and the leaf. Some of the loss is predictable and can be planned for; some indicates a kettle that has drifted.

• My white tea cake tastes nothing like the loose version

  Usually leaf quality5 likely causes

  A pressed white tea cake gives a darker, heavier, fruitier cup than loose white tea from the same grade, and the delicate hay-and-melon character is missing.

  Compression is not a packaging decision. Steaming the leaf to press it and then holding it in a dense form changes both what the tea is on the day it is made and how it develops afterwards, so a cake and a loose tea of the same grade are genuinely different products.

• My white tea tastes of almost nothing

  Usually temperature5 likely causes

  The cup is pale and barely flavoured, and it stays that way whatever is adjusted.

  White tea is routinely brewed as though it were the most delicate thing in the cupboard, and it is the category that most often wants the opposite. The leaf is bulky, lightly worked and slow to give anything up.

• My young sheng pu-erh is unbearably harsh

  Usually leaf quantity5 likely causes

  A recent raw pu-erh is aggressively bitter and drying from the first infusion, with a rasping quality that stays in the throat.

  Young sheng is genuinely harsh, and some of it is meant to be — the material bought for long ageing is often the least pleasant to drink now. Separating the part that is the tea from the part that is the brewing is the whole diagnosis here, and bitterness and drying astringency have different causes within it.

• Tea from my cafetière is cloudy and turns bitter

  Usually equipment5 likely causes

  The first cup out of a French press is acceptable and the rest is murky, silty and increasingly harsh.

  A cafetière is a good tea vessel with two specific and fixable problems, both of them consequences of hardware designed for coffee. The mesh is far coarser than tea needs and the plunger does not end the steep, so the tea keeps extracting in the pot while sediment passes into every cup.

• Tea from my flask tastes stewed by mid-morning

  Usually over-extraction5 likely causes

  Tea that was fine when it went into the flask is dark, thick and harshly drying an hour or two later, and worse again by lunchtime.

  A vacuum flask is very good at what it does, which is the problem. Held near brewing temperature for hours, leaf keeps extracting long past the point of pleasure, and the fix is about what goes in the flask rather than about the flask itself.

• Tea from the office boiler or the hot tap never tastes right

  Usually equipment5 likely causes

  The same tea that works at home is thin, flat or stewed when made from a plumbed hot tap, a wall boiler or a catering urn.

  Two separate faults hide behind one symptom, and they pull in opposite directions. The water is usually not as hot as the label claims, which under-extracts; and it has usually been sitting hot for a long time, which changes it before it ever meets the leaf. The fix depends on which of the two you have, and it is often both.

• Tea runs down the outside when I pour

  Usually technique4 likely causes

  Liquor escapes past the lid or dribbles down the outside of the gaiwan or pot instead of going into the pitcher.

  Three separate faults produce the same mess: the lid gap is wrong, the pour is too slow, or the vessel is overfilled. All three are technique rather than defects, and the first is the one nobody is told about.

• The dry leaf smells wonderful and the tea tastes of nothing

  Usually under-extraction5 likely causes

  Opening the packet gives a strong, attractive aroma that has largely disappeared by the time the tea is in the cup.

  Aroma and flavour come apart more in tea than in most drinks, and the gap has several quite different causes — some in the brewing, some in the leaf, and one that is simply a property of how aroma is perceived from a packet against a cup.

• The first cup from my pot is weak and the last is bitter

  Usually over-extraction4 likely causes

  Pouring several cups in sequence from one pot gives noticeably different tea in each, with the last cup much stronger and often harsh.

  A teapot does not hold one uniform liquid. Strength increases from the top of the pot to the bottom and it continues rising while the pot stands, so pouring in sequence ensures that the person served last gets a different drink from the person served first.

• The leaf clogs my strainer and the pour stops

  Usually equipment4 likely causes

  Liquid backs up behind the strainer or the pot’s built-in filter, and the last of the tea will not come through.

  Fine leaf and fine mesh are a bad combination, and the answer is usually a coarser filter rather than a finer one. A clogged filter also means the tea sat in the vessel longer than intended, which is a second fault hiding behind the first.

• The leaves swell up and push out of the infuser

  Usually equipment4 likely causes

  Wet leaf lifts the lid off the basket, escapes round the edges, or packs so tightly that water barely passes through.

  Dry leaf expands to several times its volume, and rolled and compressed teas expand most of all. Overflow is a sign that the leaf was measured by eye against the container rather than by weight against the water.

• The notes say orchid and stone fruit and I taste tea

  Usually technique6 likely causes

  The packet, the vendor page or the review describes specific flavours, and the cup tastes pleasant but general. Nothing resolves into the words used.

  This is the commonest reason people stop exploring tea, and it is worth separating into its parts, because at least one of them is not about the drinker at all. Some of these notes are describing a real thing you have not yet learned to name; some are describing a real thing your brewing is currently hiding; and some are copy. Working through them in order is quicker than trying harder.

• The same spoonful gives a different strength every time

  Usually leaf quantity4 likely causes

  Following the same recipe — a level teaspoon per cup — produces tea that is strong one day and thin the next, with no other change.

  Tea is extracted by mass and dosed by most people by volume, and the two track each other badly. Leaf density varies several times over between tea types and changes within a single packet as it settles, so a spoon is measuring something other than the amount of tea.

• The same tea tastes different from last time

  Usually leaf quality5 likely causes

  A tea you have bought before arrives tasting noticeably different, and you cannot tell whether the tea changed or you did.

  Tea is an agricultural product sold under a stable name, so a real change and an imagined one feel identical. Work through what changed on your side first, because it is usually one of four things and all of them are easy to check.

• The tea I loved in the shop is disappointing at home

  Usually water chemistry5 likely causes

  A tea that was remarkable when it was tasted in the shop is ordinary in your own kitchen, from the same packet, within days of buying it.

  Almost every variable changed between the two cups, and the leaf is the only one that did not. This is a different problem from a tea tasting different between purchases: here the tea is the same and the conditions around it are not.

• There are black spots inside my teapot or infuser

  Usually equipment5 likely causes

  Dark speckling inside a spout, under a lid seal, in the mesh of an infuser or around the gasket of a travel bottle.

  Every one of these is a place that stays wet after the rest of the vessel has dried, and that is the whole explanation. The distinction that matters is between staining, which is cosmetic and belongs there, and growth, which does not — and the two look similar in a spout you cannot see into.

• There are brown stains inside my teapot and cups

  Usually equipment4 likely causes

  A brown or grey-brown film builds up on the inside of the pot and in the bottom of cups, and rinsing does not shift it.

  Mostly cosmetic, and worth knowing which parts are cosmetic and which are not. On glazed and glass ware the stain is harmless and removable; on unglazed clay it is the seasoning the vessel exists for and should be left alone.

• There are two dates on my Japanese tea and I cannot tell which matters

  Usually leaf quality4 likely causes

  A packet of sencha or matcha carries more than one date, some of it in Japanese only, and none of it makes clear how old the tea in the packet actually is.

  Japanese tea packaging routinely carries a packing or processing date and a best-before date, and they answer different questions. The best-before is a shelf-life estimate the packer chose; the packing date is closer to a fact. Neither is the harvest date, which is the thing a buyer actually wants and which is often not printed at all — and for a category that fades as fast as Japanese green tea, the gap between those three is the difference between a fresh tea and a tired one at the same price.

• There is an oily film on the surface of my tea

  Usually technique5 likely causes

  An iridescent or dull skin sits on the surface of a cup or pot, breaking into patches when disturbed and clinging to the side as the level drops.

  This is not dirt, grease or residue, and washing the cup harder does nothing. It forms where tea compounds meet air in the presence of dissolved minerals, so it is a property of your water interacting with your tea rather than of either alone — which is why it appears reliably in some houses and never in others.

• There is scale in my kettle and a film on my tea

  Usually water chemistry4 likely causes

  Chalky white deposits build up inside the kettle, flakes appear in the cup, and an oily-looking film sits on the surface of the tea.

  Two related problems with one root. Scale is dissolved mineral coming out of solution when water is boiled; the surface film is a separate effect of hard water on the tea itself. Descaling fixes the first and only partly helps the second.

• There is sediment in the bottom of my cup

  Usually technique5 likely causes

  A layer of fine dark particles settles out, and the last mouthful is gritty.

  Distinguish sediment from cloudiness first: cloudiness stays suspended and is often intended, while sediment settles and usually is not. Once separated, the causes are mostly filtration and leaf grade.

• We fitted a water softener and the tea got worse

  Usually water chemistry4 likely causes

  Since a softener was installed the kettle stays clean and the tea tastes flat, slightly salty or oddly soft, with the brightness gone.

  A domestic ion-exchange softener does not take minerals out of water. It swaps calcium and magnesium for sodium, so the total dissolved load is unchanged and only its composition has moved — which is a different intervention from filtering, and it happens to be the wrong direction for tea.