Why Does My Candle Burn Straight Down the Middle?

Why Does My Candle Burn Straight Down the Middle?

 

Eco Candle Wicks from ₹59 / 10 · glass jars from ₹31.86 each Soy wax from ₹260 / 500g Stocked in India · ships nationwide
CSI troubleshooting guides
A narrow shaft down the centre with thick walls standing is not ordinary tunnelling. It is a wick that was never big enough for the jar.
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"Quality of the wick is good for jar candles, team can work on the pricing and delivery timelines."
Monika DeepVerified buyer · Oct 2025
Eco Candle Wicks
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"Good quality .... if possible delivery date would be try little bit quick please"
Subhankar RoyVerified buyer · Sep 2024
Eco Candle Wicks
★★★★★
"Quality wick, works very well"
AshwiniSep 2025
Eco Candle Wicks
★★★★★
"The jars were of good quality"
Soumili GopeVerified buyer · Mar 2026
Clear Glass Jar with Golden Lid
★★★★★
"One of the best wax for container Candles. Easy to work with, especially if you are a beginner."
ThenirvaofficialVerified buyer · Nov 2025
Luxury Soy Wax CSI 464
★★★★★
"Good one"
Sneha TamangVerified buyer · Apr 2025
Premium Candle Wicking Needle
★★★★☆
"Quality of the wick is good for jar candles, team can work on the pricing and delivery timelines."
Monika DeepVerified buyer · Oct 2025
Eco Candle Wicks
★★★★☆
"Good quality .... if possible delivery date would be try little bit quick please"
Subhankar RoyVerified buyer · Sep 2024
Eco Candle Wicks
★★★★★
"Quality wick, works very well"
AshwiniSep 2025
Eco Candle Wicks
★★★★★
"The jars were of good quality"
Soumili GopeVerified buyer · Mar 2026
Clear Glass Jar with Golden Lid
★★★★★
"One of the best wax for container Candles. Easy to work with, especially if you are a beginner."
ThenirvaofficialVerified buyer · Nov 2025
Luxury Soy Wax CSI 464
★★★★★
"Good one"
Sneha TamangVerified buyer · Apr 2025
Premium Candle Wicking Needle
Reviews collected and published through Judge.me on candlemakingsuppliesindia.store. They are general reviews of the products named, not reports about shafting or tunnelling. Wording is unedited; "Verified buyer" appears only where Judge.me recorded one.
✓ Wicks sold in 10s so you can test before you commit ✓ 80 containers in the jar collection ✓ GST invoicing · MSDS & IFRA documentation on request
Candle Troubleshooting · Burn Faults
Ordinary tunnelling leaves a ring of wax around the edge. This leaves a shaft — a narrow vertical hole with thick walls standing all the way up. It is a different fault with a different cause, and unlike a ring it gets worse on its own.
9.8%
the share of an 80 mm jar's surface a 25 mm shaft is actually using · the other 90.2% is wall · CSI live pricing, September 2026
Quick answers — read this first
Why is my candle burning a hole straight down the middle? Because the flame is only melting the wax directly under it. Almost always the wick is badly undersized for the jar diameter, or the candle has been burned in repeated short bursts, or both.

How is that different from tunnelling? Tunnelling leaves a ring — a rim of unmelted wax an inch or so thick. A shaft leaves a tube — walls that stand the full height while the flame sinks. Same family, far worse stage.

Does it fix itself? No. It is a feedback loop. The deeper the shaft, the less oxygen and radiated heat reach the walls, so each burn melts less wall than the one before.

Can I save the candle? A shaft under about 10 mm deep usually responds to the foil method. Deeper than roughly 20 mm and it is a write-off — and once the wick is sitting in a well of its own molten wax, that is a safety problem, not a cosmetic one.
The short answer
Diagnose it: ring of wax at the edge = tunnelling. Vertical tube with walls standing to the rim = shafting. Shafting means the wick is far too small for the diameter, not slightly too small.
Understand why it worsens: the flame drops below the rim, gets less air, radiates less heat sideways, and the thick walls insulate what is left. Every burn makes the next one shorter.
Fix it at the bench: wick up a size, burn-test three identical jars side by side, and if the internal diameter is above roughly 80 mm accept that one wick will not do it — add a second wick or move to a narrower jar.
Shop: Candle Wicks · Containers · Candle Wax · sizing help on WhatsApp.
The shaft feedback loop — the same jar, four burns, nothing changed but the wax BURN 1 Pool 40 mm · flame at the rim BURN 2 Pool 32 mm · flame 10 mm down BURN 3 Pool 26 mm · flame 25 mm down BURN 4 Pool 22 mm · wick drowning Narrower shaft → flame sits lower → less oxygen, less heat radiated sideways → less wall melted → narrower shaft
Cross-section of one jar over four burns. Nothing about the candle changes between panels — same wick, same wax, same room. The pool narrows from 40 mm to 22 mm purely because the geometry of the previous burn made the next one worse. By burn four the flame is 40 mm below the rim, the standing wall is thicker than the shaft is wide, and the wick is sitting in a well of its own molten wax. That last state is the one to stop burning at.
Straight answer
Why does a candle burn a narrow shaft straight down the middle instead of melting across?
Because the flame is producing enough heat to melt the wax immediately beneath it and nowhere near enough to melt the wax beside it. A candle flame heats sideways by radiation, and that radiated heat falls off fast with distance. If the wick is badly undersized for the jar's internal diameter, the melt pool never reaches the glass even on a long first burn, so the outer wax is never touched. Burn it again and the flame is already a few millimetres lower, so it radiates less to the walls than it did the first time. Repeat that four or five times and you have a shaft: a tube of clear wax with a flame at the bottom of it and walls standing to the rim. It is the extreme form of the fault covered in why is my candle tunnelling, and the difference matters: a ring can be melted back, a shaft usually cannot. The three things that produce it are a severely undersized wick, repeated short burns, and a jar too wide for a single wick to ever serve. The last of those is the one no wick purchase will fix — you change the jar or you add a second wick. Everything else on this page follows from those three.
One line: a ring means the wick is a size small; a shaft means the wick was never in the right range for the diameter — and once the shaft forms, every burn digs it deeper.
The diagnostic costs one wick. Eco Candle Wicks are ₹59 for 10 in Thin (C1) and ₹188.80 for 20 in Thick (C2) — buy the small packs, pour three identical jars, and let the burn test tell you which one opens the pool. Do not order 500 of anything before that test.
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Shaft or ring: work out which fault you actually have

Both faults leave unmelted wax. Only one of them leaves a candle you can still rescue.

Look down into the jar once the candle has cooled. A rim of solid wax around the edge with a broad shallow dish in the middle is ordinary tunnelling: the pool got most of the way to the glass and stopped. The unmelted band is usually 5 mm to 15 mm thick, most of the surface still melted, and the flame sits more or less level with the rim. That is a size-and-a-bit problem — the wick is one step small, or the first burn was cut short — and it is recoverable.

A narrow vertical hole with walls standing all the way to the rim is a shaft. The melted area is a small circle in the centre, the standing wall is often thicker than the hole is wide, and the flame is visibly sunk below the glass. This is not the same fault a size larger — it is a candle whose pool never reached the glass on any burn.

Diagnosis · same family, different stage
Ordinary tunnelling against a shaft, on the same 80 mm jar
Check Ordinary tunnelling (ring) Shafting (tube)
What is left standing A rim of wax 5–15 mm thick with a wide dish inside A full-height wall with a narrow hole bored through it
Melt pool diameter 60–70 mm on an 80 mm jar 20–30 mm on the same jar
Surface actually working 28.3–38.5 cm² of 50.3 cm² · 56–77% 3.1–7.1 cm² of 50.3 cm² · 6–14%
Flame position after 3 burns At the rim or a few mm below 15–40 mm below the rim
Likely cause Wick one size small, or one short first burn Wick far outside the right range, or short burns every time
Does it get worse on its own Slowly. A long burn can recover it Yes, fast. Each burn starves the next
Recoverable Usually — see how to fix tunnelling Rarely. Foil helps a shallow shaft; a deep one is finished
Wax you lose 10–20% of the fill 55–75% of the fill, stuck to the glass

The wasted-wax line is what should get a business owner's attention. A 200 g candle poured in Luxury Soy Wax CSI 464 at ₹507.40 per kilogram carries ₹101.48 of wax. A ring costs the customer perhaps ₹15 of that; a shaft that strands 65% of the fill costs them ₹65.96 they paid for and cannot burn, plus the fragrance dissolved in it. They will not do that arithmetic. They will decide the candle was bad and not reorder.

The quick field test
Rest a ruler across the rim and measure straight down to the wax at the centre, then to the wax at the edge. Under about 10 mm between the two readings is a dish, and a long burn may still fix it. Over 20 mm is a shaft, and no amount of ordinary burning brings the walls back down. Measure before you decide — the eye consistently under-reads depth through glass.

Why a shaft compounds instead of correcting itself

This is what separates shafting from every other burn fault, and why "just burn it longer next time" fails here. A shaft is self-reinforcing. Four things change once the flame drops below the rim, and all four push the same way.

1
The flame drops below the rimA flame heats the wax around it mainly by radiating sideways, and that heat falls off fast with distance. While the flame sits at or above the rim it radiates freely across the whole surface. Once it is 15 mm down inside a hole, the top of the wall is no longer in a straight line from the flame — the wall itself is in the way. The surface that most needs heat is shadowed from it by the wax you are trying to melt.
2
The flame gets less oxygenA flame at the bottom of a narrow tube draws air down a 25 mm shaft against its own rising exhaust. Air supply drops and the flame burns shorter, cooler and dimmer than the same wick would in open air — the flame that stood 25 mm tall on burn one is a guttering stub by burn four. A smaller flame produces less heat in total, so there is less of it to radiate anywhere.
3
The standing walls insulate what is leftSolid wax conducts heat poorly — that is why a candle works at all. The thicker the wall, the more mass sits between flame and glass, and the less the glass warms. Warm glass is one of the things that normally helps a pool spread to the edge on later burns; a shafted candle never gets it.
4
The pool gets smaller, so the next burn is shorterA narrower pool means less molten wax feeding the wick, which caps how long the candle burns steadily before the wick starts drowning in a well it cannot draw from. The burn that could have melted the wall back is now the burn that ends early. Each cycle removes a little more of the mechanism that would have fixed the problem.

Put those four together and you get the loop drawn at the top of this page: narrower shaft, lower flame, less oxygen, less radiated heat, less wall melted, narrower shaft. Nothing external needs to change. The same candle in the same room produces a worse result on every successive burn — which is why a customer reporting "it was fine at first and then it just went down a hole" is describing exactly the expected behaviour.

The CSI principle
Tunnelling is a mistake the candle makes once. Shafting is a mistake the candle keeps making, using the result of the last one as its excuse.
Which is why the fix has to happen at the bench, before the jar leaves you. There is no burning instruction on a care card that recovers a candle whose wick was never in the right range for its diameter.

The three causes, and the evidence that tells them apart

A shaft has three plausible origins. Two are yours to fix at the bench; one belongs to the customer. Work out which before changing anything — the wrong fix costs money and leaves the fault in place.

Cause 1 — the wick is severely undersized for the diameter

The common one, and in any jar above about 70 mm internal diameter it is the default assumption — the sizing case is argued in full in is my candle tunnelling because the wick is too small. A wick one step small gives a ring. A wick two or three steps small — or a votive wick in a tumbler — gives a shaft, because the pool it sustains is only ever 20 mm to 30 mm across however long it burns.

The evidence. Light a fresh candle from the same batch, leave it four uninterrupted hours, measure the pool. If it has not reached the glass by then it never will, and burn duration is not the variable — the expected timings are in how long a candle should take to reach a full melt pool. Second tell: the flame on burn one is short and steady with no soot — a well-behaved-looking candle that is actually starved. Fix: wick up and re-test, changing nothing else in that batch.
Cause 2 — the candle has been burned in repeated short bursts

A correctly wicked candle lit for forty minutes each evening can shaft on a wick that would otherwise have been fine. The first burn sets the memory ring: wherever the pool stops on burn one is roughly where it stops every time after. Forty minutes does not reach the glass in most container sizes, so the candle sets a small pool and repeats it, the flame a little lower each time.

The evidence. Two candles from the same pour behave differently — yours opens to the wall in a proper test, the customer's has a shaft. That is a usage pattern, not a manufacturing fault. The other tell is shape: a burn-duration shaft has a visible step or shoulder a centimetre or two down where the first short burn stopped, with a narrower bore below. A wick-size shaft is a smooth taper from the top. Fix: a care sticker, and a wick with enough margin that one short burn does not doom the jar.
Cause 3 — the jar is simply too wide for one wick

Uncomfortable, because the fault is then a design decision rather than a supply problem. Pool area grows with the square of the diameter: a 100 mm jar is not 25% harder to burn than an 80 mm one, it is 56% more surface to melt from a single point of heat. Past a certain width no cotton wick holds an even pool without running hot enough to soot, mushroom and overheat the glass — trading one fault for a worse one.

The evidence. You have wicked up twice already, and the largest wick tested either still shafts or opens the pool while throwing soot, mushrooming within an hour and leaving the glass too hot to hold. Both say the same thing: the diameter is beyond what one wick can serve. Fix: two wicks, or a narrower jar. There is no third option.
If the jar is too wide for one wick, no wick purchase fixes it. Change the jar or add a wick.
— CandleMakingSuppliesIndia

We sell wicks, and we would rather sell two than watch someone buy up a ladder that ends before their jar does. Two Eco Candle Wicks in Thin (C1) is ₹11.80 of wick per candle — cheaper than the third and fourth thick wick bought forcing a single-wick answer onto a diameter that will not take one, and far cheaper than the returns.

Can the candle be saved?

Sometimes. It depends on how deep the shaft already is, and for most of the jars people photograph and send us the honest answer is no. Measure first.

1
Measure the wall, not the holeRest a straight edge across the rim, measure down to the top of the standing wall, then down to the wax at the bottom of the shaft. The difference is the wall height you have to melt back. Under 10 mm: foil usually works. 10–20 mm: worth one attempt. Over 20 mm: stop, and read the write-off below.
2
Trim the wick to 5 mm firstA long or mushroomed wick soots heavily inside a collar and defeats the exercise. Use a wick trimmer at ₹177 or scissors, take the carbon ball off completely, and clear the trimmings out of the pool.
3
Build the foil collarWrap kitchen foil around the outside of the jar so it stands 25–30 mm proud of the rim, then fold the standing part inwards to leave a hole about 30–40 mm across over the wick. The collar reflects heat back down onto the standing walls and holds warm air over the wax. Keep the hole above about 25 mm or you starve the flame.
4
Burn for two to three hours, watchedDo not leave it — foil conducts, and the collar gets hot. Check every twenty minutes: the top edge should be slumping inwards and the pool widening. When the pool reaches the glass all round, blow it out, let it set, remove the foil and look. A level surface means it is recovered. If the wall has barely moved after three hours, it will not move on a fourth.
The honest verdict on a deep shaft: it is a write-off. Once the standing wall is over about 20 mm the flame is too far down the hole to radiate onto the top edge at all, and foil cannot redirect heat that never reaches the collar. A hot air gun at ₹531 will melt the wall level, and reworking a shipment before it ships is legitimate — but it is not a customer instruction, and "point a heat gun into a jar of molten wax" does not go on a care card. For the buyer the candle is finished; for you it is a replacement plus a wick change next batch.
A drowning wick is a safety matter, not a cosmetic one
When the well fills with molten wax faster than the wick can draw it, several things change at once. The wick can drown and go out unnoticed, leaving hot liquid in a jar the customer assumes is off. The flame sits close to one point on the glass, heating a small area far more than the rest — and localised heating is exactly the condition that stresses a glass container. A standing wall can also slump and dump solid wax onto a small flame. Tell customers plainly: stop burning when the flame is well below the rim, when the pool is deeper than it is wide, or when less than 10 mm of wax remains. That belongs on the care card, not in a troubleshooting reply afterwards.
Shipping a festive run? Diwali 2026 falls on 8 November. A wick that shafts does not show up until the third or fourth burn — for gifts bought in late October, well after the money has changed hands. Burn-test now, not in packing week. Bulk wick and jar pricing, GST invoicing and documentation on WhatsApp.
Bulk pricing on WhatsApp

The fix in the recipe, and the arithmetic that decides it

Two decisions close this fault permanently: which wick, and how many. Both are settled by the internal diameter, and the number that matters is melt pool area — πr², where r is half that diameter in centimetres. Work it out before buying anything: it tells you straight away whether one wick can ever serve the vessel.

Pool area by internal diameter · πr²
What one wick is asked to melt, and what a 25 mm shaft is actually using
Internal Ø Full pool area A 25 mm shaft uses Two wicks: each Verdict
50 mm 19.63 cm² 25.0% Not needed Comfortable for one wick
60 mm 28.27 cm² 17.4% Not needed One wick, thin or thick by wax
70 mm 38.48 cm² 12.8% 19.24 cm² One thick wick, burn-tested
80 mm 50.27 cm² 9.8% 25.13 cm² Practical limit for one cotton wick
90 mm 63.62 cm² 7.7% 31.81 cm² Two wicks. One shafts or soots
100 mm 78.54 cm² 6.3% 39.27 cm² Two minimum, sometimes three

Read the third column and the fault stops being mysterious. In a 50 mm votive a 25 mm shaft still uses a quarter of the surface, so the candle limps along and often recovers. In a 100 mm tumbler it uses 6.3% — the other 93.7% is wall, and will still be wall when the candle is binned.

The fourth column is the argument for two wicks. Split a 100 mm jar and each wick handles 39.27 cm² — almost exactly the job of one wick in a 70 mm jar, a problem you already know how to solve. Split a 90 mm jar and each handles 31.81 cm², a 63 mm candle. Two wicks do not make a wide candle burn hotter; they make it two ordinary candles sharing a jar. Set them halfway between centre and glass on opposite sides, held by a wick centering device at ₹118 for 5.

Then burn-test three jars, side by side, on the same day

A chart narrows the field; it does not settle it, because the pool a wick holds depends on wax, fragrance load, dye and glass thickness as well as diameter. Three identical jars, three wicks, one melt, the same cure, lit together. What you want is a pool that reaches the glass in two to four hours with a steady flame, no soot and no mushroom — the pool-formation detail sits in why isn't my candle creating a full melt pool. Under 90 minutes is running hot; not there at four hours is undersized, and it will shaft.

1
Cotton · the standard ladder
Eco Candle Wicks — Thin (C1) and Thick (C2)
Two sizes — a bracket to test inside, not a full ladder. C1 starts votives and narrow tumblers; C2 is where you go when a 60–80 mm jar rings or shafts. At ₹5.90 and ₹9.44 per wick at every pack size, both are cheap enough to test properly. The C2 pack of 10 was out of stock on the September 2026 pull; the 20 was not.
Pack Thin (C1) Thick (C2) Per wick
10 ₹59.00 Out of stock ₹5.90 / ₹9.44
20 ₹118.00 ₹188.80 ₹5.90 / ₹9.44
50 ₹295.00 ₹472.00 ₹5.90 / ₹9.44
100 ₹590.00 ₹944.00 ₹5.90 / ₹9.44
500 ₹2,950.00 ₹4,720.00 ₹5.90 / ₹9.44
₹11.80 for two C1 wicks in one wide jar Buy Eco Candle Wicks
2
Cotton braided · the third data point
Cotton Braided Wicks Ready Made
Pre-tabbed and ready to place, at a flat ₹12.00 per wick whatever quantity you buy. Its value here is a third burn characteristic instead of a two-way choice, for almost the same money.
Pack Price Per wick Enough for
10 ₹120.00 ₹12.00 The test, plus spares
50 ₹600.00 ₹12.00 A small batch
100 ₹1,200.00 ₹12.00 100 single-wick candles
500 ₹6,000.00 ₹12.00 250 twin-wick jars
1000 ₹12,000.00 ₹12.00 Festive volume
₹120.00 buys the whole third arm of the test Buy Cotton Braided Wicks
3
Wooden · only after the cotton ladder fails
Performance Wooden Wicks (Imported)
A wooden wick burns with a wide, flat flame front rather than a point — a genuinely different way of attacking a wide jar. It is also ₹59.00 a wick against ₹5.90 for a cotton C1, ten times the cost. If two C2 wicks give a clean pool in an 80 mm jar for ₹18.88, buy that and stop. Wooden wicks earn their price on a premium line where the crackle is part of what the customer pays for, not as a repair for a wick size you have not tested.
Pack Price Per wick Against Eco C1
10 ₹590.00 ₹59.00 10.0× the cost
50 ₹2,360.00 ₹47.20 8.0× the cost
100 ₹4,130.00 ₹41.30 7.0× the cost
₹41.30–₹59.00 per wick · a product decision, not a fix Buy Performance Wooden Wicks
What the test spread costs

The whole diagnostic priced out of live CSI stock, everything in the smallest useful pack.

The burn-test spread · CSI live pricing, September 2026
Everything needed to settle a wick size, and what it comes to
Item What you buy Price
Jars White Matte Glass Jar, 5 (₹70.80 each) ₹354.00
Wick A Eco Candle Wicks Thin (C1), 10 wicks ₹59.00
Wick B Eco Candle Wicks Thick (C2), 20 (10-pack out of stock) ₹188.80
Wick C Cotton Braided Wicks Ready Made, 10 ₹120.00
Wax Luxury Soy Wax Chunks, 1 kg ₹599.00
Fixing Candle Wick Stickers, 40 (₹2.50 each) ₹100.00
Core spread Three wick options, jars, wax, fixings ₹1,420.80
Optional + Wick Centering Device, pack of 5 (₹23.60 each) ₹1,538.80
Optional + Performance Wooden Wicks, 10, as a fourth arm ₹2,128.80
What the three test candles actually consume: 3 jars at ₹70.80 = ₹212.40 · one wick of each type (₹5.90 + ₹9.44 + ₹12.00) = ₹27.34 · 540 g of wax at ₹599.00/kg = ₹323.46 · 3 wick stickers at ₹2.50 = ₹7.50. Total consumed: ₹570.70, or ₹190.23 per test candle. The rest goes into production. One shafted 200 g candle strands roughly ₹66 of wax plus its fragrance — ₹3,300 across a batch of fifty, before a single refund.
Then hand the customer the other half of the fix

A correctly wicked candle can still be shafted by the person burning it, and the three instructions that prevent it are short enough to print. First burn to the wall: two to four hours, or until the pool reaches the glass all round — the first burn sets the memory ring. Two to four hours after that: long enough to hold the pool at full width, short enough that the wick does not drown or the glass overheat. Trim to 5 mm before every light: an untrimmed wick mushrooms, soots and burns taller and less steadily. Those three lines fit on a Candle Care Stickers Roll — ₹413.00 for 500 one-inch stickers, ₹0.83 a candle, or ₹699.00 for 1,000 at 1.5 inches, ₹0.70 each.

₹0.83 against a ₹66 loss
The cheapest line on this page, and it addresses cause two entirely. Someone burning forty minutes a night is not careless — nobody told them the first burn was different. Print it, and that version of the fault stops reaching your inbox. It does nothing for cause one or cause three: those are yours to fix at the bench.
Why trust this guide

CANDLEMAKINGSUPPLIESINDIA supplies raw materials, not finished candles. The commercially convenient version of this page would send every reader up the wick ladder one purchase at a time. We have instead told you that above roughly 80 mm of internal diameter the ladder ends, and that the answer is a second wick or a narrower jar — which on our own catalogue means two ₹5.90 wicks rather than a run of increasingly expensive single ones. A maker whose candles shaft stops reordering, so the honest answer and the commercial one point the same way.

Every price on this page comes from live CSI stock on 10 September 2026 and links to the product page, where current pricing, variants and availability always take precedence. Where a variant was out of stock on that pull — the Eco Candle Wicks Thick (C2) pack of 10 — it is named as such rather than quietly omitted. Melt pool areas are plain πr² arithmetic from nominal internal diameters, and the 80 mm single-wick limit is a working rule from burn testing, not a certified figure; your wax, fragrance load and glass thickness will move it.

For bulk wick and jar pricing, GST invoicing, MSDS and IFRA documentation, or help matching a wick to a specific internal diameter, message us on WhatsApp at +91 7397976926. Send the internal diameter in millimetres and the wax you are pouring — those two numbers are what the answer depends on.

Frequently asked questions

Why is my candle burning straight down the middle instead of across?
Because the flame is only melting the wax directly beneath it. The cause is almost always a severely undersized wick for the jar's internal diameter, a pattern of repeated short burns, or a jar too wide for one wick. Test which it is by burning a fresh candle from the same batch for four uninterrupted hours: if the pool still has not reached the glass, the wick is the fault and burn length is not the variable.
Is this the same as tunnelling?
Same family, far worse stage. Ordinary tunnelling leaves a ring — a rim of unmelted wax 5 to 15 mm thick with a wide dish inside it, and a long burn will often melt it back. Shafting leaves a tube — walls standing to the rim with a 20 to 30 mm hole bored down the centre. On an 80 mm jar a ring still has 56–77% of the surface working; a shaft has 6–14%. The general ground is covered in why is my candle tunnelling and the tunnelling troubleshooting hub; this page is only the extreme form.
Why does it keep getting worse every time I light it?
Because it is a feedback loop. Once the flame sinks below the rim it is shadowed from the wall by the wax it needs to melt, it draws less oxygen down a narrow shaft so it burns smaller and cooler, and the thick standing walls insulate the glass that would otherwise help the pool spread. Less wall melts, the shaft narrows, and the next burn starts from a worse position. Nothing external changes — the candle degrades itself.
Does the foil trick actually work?
On a shallow shaft, yes. Trim the wick to 5 mm, wrap foil around the jar so it stands 25–30 mm above the rim, fold it inwards to leave a 30–40 mm hole over the flame, and burn for two to three hours while watching it — the collar gets hot. Under about 10 mm of standing wall it usually recovers. Between 10 and 20 mm it is worth one attempt. Over 20 mm the candle is a write-off: the flame is too deep to radiate onto the wall at all, and foil cannot redirect heat that never arrives.
Is a candle burning down the middle dangerous, or just ugly?
It becomes a safety matter once the wick is drowning in a deep well of its own molten wax. The wick can go out unnoticed leaving hot liquid in a jar assumed to be off; the flame sits close to one point on the glass and heats it far more than the rest, which is exactly the condition that stresses a glass container; and a standing wall can slump and drop solid wax onto a small flame. Tell customers to stop burning when the flame is well below the rim, when the pool is deeper than it is wide, or when less than 10 mm of wax remains.
How wide a jar can one wick handle?
As a working rule from burn testing, about 80 mm of internal diameter — 50.27 cm² of pool. Above that, a single wick either shafts or runs so hot it soots, mushrooms and overheats the glass. Two wicks in a 100 mm jar give each one 39.27 cm², almost exactly the job of a single wick in a 70 mm jar. At ₹5.90 per Eco Candle Wick, the second wick costs less than the fault does. If the jar is too wide for one wick, no wick purchase fixes it.
Settle the wick, kill the shaft
Three jars, three wicks, one afternoon. ₹570.70 of materials against ₹66 of stranded wax per candle.
Eco Candle Wicks from ₹59 for 10 in Thin (C1) and ₹188.80 for 20 in Thick (C2), Cotton Braided Wicks at ₹12.00 each, Performance Wooden Wicks from ₹41.30, White Matte Glass Jars at ₹354 for 5, Luxury Soy Wax Chunks from ₹299 per 500 g and Candle Care Stickers at ₹0.83. Send us your internal diameter in millimetres and we will tell you where to start testing.
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Editorial standards & sources
About this guide: Written by the CANDLEMAKINGSUPPLIESINDIA team. Product recommendations reflect the CSI range; the diagnosis, the πr² arithmetic and the burn-test method apply to any supplier's materials.

Customer reviews: The six reviews at the top of this page are genuine, published Judge.me reviews left by CSI customers on the product pages named. They are general reviews of those products, not accounts of shafting or tunnelling. Names, star ratings, dates and products are as recorded by Judge.me and the wording is unedited. "Verified buyer" appears only where Judge.me recorded a verified buyer: Monika Deep (4★, Eco Candle Wicks, Oct 2025), Subhankar Roy (4★, Eco Candle Wicks, Sep 2024), Soumili Gope (5★, Clear Glass Jar with Golden Lid, Mar 2026), Thenirvaofficial (5★, Luxury Soy Wax CSI 464, Nov 2025) and Sneha Tamang (5★, Premium Candle Wicking Needle, Apr 2025). Ashwini (5★, Eco Candle Wicks, Sep 2025) is published but not recorded as a verified buyer and carries no badge. No locations are shown, because Judge.me does not store them.

Figures, and where each comes from. All prices are CSI live pricing pulled 10 September 2026 and are listed variant prices excluding tax and shipping. Wicks: Eco Candle Wicks Thin (C1) ₹59.00/10, ₹118.00/20, ₹295.00/50, ₹590.00/100, ₹2,950.00/500 — ₹5.90 each at every pack; Thick (C2) ₹188.80/20, ₹472.00/50, ₹944.00/100, ₹4,720.00/500 — ₹9.44 each, with the pack of 10 out of stock on the pull date. Cotton Braided Wicks Ready Made ₹120.00/10 to ₹12,000.00/1000 — ₹12.00 each at every pack. Performance Wooden Wicks (Imported) ₹590.00/10 (₹59.00), ₹2,360.00/50 (₹47.20), ₹4,130.00/100 (₹41.30). Wick tools: Wick Centering Device ₹118.00 per 5 (₹23.60); Candle Wick Stickers ₹100.00 per sheet of 40 (₹2.50); Candle Wick Cutter / Trimmer ₹177.00; Hot Air Gun ₹531.00. Jars: White Matte Glass Jar ₹354.00 per 5 (₹70.80 each); Clear Glass Votive Jar 70 g ₹159.30 per 5 (₹31.86 each). Wax: Luxury Soy Wax Chunks ₹299.00/500 g and ₹599.00/kg; Luxury Soy Wax CSI 464 flakes ₹260.00/500 g and ₹507.40/kg. Care stickers: Candle Care Stickers Roll ₹413.00 per 500 at 1 inch (₹0.83 each) and ₹699.00 per 1,000 at 1.5 inches (₹0.70 each). Calculations: pool areas are πr² from nominal internal diameters — 50 mm = 19.63 cm², 60 mm = 28.27 cm², 70 mm = 38.48 cm², 80 mm = 50.27 cm², 90 mm = 63.62 cm², 100 mm = 78.54 cm²; a 25 mm shaft is 4.91 cm². The stranded-wax figure assumes a 200 g candle in CSI 464 at ₹507.40/kg (₹101.48 of wax) with 65% unburned. The core burn-test spread of ₹1,420.80 is ₹354.00 + ₹59.00 + ₹188.80 + ₹120.00 + ₹599.00 + ₹100.00; the ₹570.70 consumed figure is 3 jars at ₹70.80, one wick of each type, 540 g of wax at ₹599.00/kg and 3 stickers at ₹2.50. The 80 mm single-wick limit and the 2–4 hour burn window are working rules from burn testing, not certified specifications. Diwali 2026 falls on 8 November. Prices and availability change — the linked product pages are always authoritative.
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