I'm Getting Random Glass Breakage in Production — How Do I Separate a Jar-Quality Problem From a Pouring-Temperature Problem?

I'm Getting Random Glass Breakage in Production — How Do I Separate a Jar-Quality Problem From a Pouring-Temperature Problem?

 

Pen Thermometer ₹354.00 Steel Pouring Pitcher Large ₹708.00 Split-test kit ₹1,416.00
Production breakage · test, don't guess
Find out whether it is the jars or the pour before you change supplier, wax or temperature.
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"I have been using this melter for about 9 months now and it is simply the best. In terms of melting time, 10 kgs of wax melts in mere 20-30 minutes, the funnel is soo good, the wax is never stuck. I do not have to worry about temperatures at all, since the temperature knob does everything for me. Most of all, this is very very cost effective. Same thing is sold via ToAuto for ₹45,000 and in that too we need to get a step down converter worth ₹12,000 which is the worst thing., as the total investment then would be ₹57,000."
Sonal SahaniNov 2024
WAX MELTER FOR CANDLE MAKING
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"Highly recommended for candle making. Convenient to use."
Mohabatti Ki DukaanVerified buyer · Jan 2026
[1 Year Warranty] Mini Electric Wax/Soap Melter (1 litre capacity)
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"Soy wax quality is the best, which ever products ordered were properly packed and delivered as early as possible, timely response to the inquiries. Good service"
Jaya SawlaniVerified buyer · Nov 2025
Luxury Soy Wax CSI 464 (Flakes Form) For Container Candles
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"Good product"
Biny AbrahamVerified buyer · Feb 2026
Black Glass Jar with Black Lid (150 gram) (Deliveries Starting 5th Dec)
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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
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"Wax quality are very good"
Sakshi JainVerified buyer · Sep 2026
Luxury Soy Wax Chunks for Jar / Container Candles
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"I have been using this melter for about 9 months now and it is simply the best. In terms of melting time, 10 kgs of wax melts in mere 20-30 minutes, the funnel is soo good, the wax is never stuck. I do not have to worry about temperatures at all, since the temperature knob does everything for me. Most of all, this is very very cost effective. Same thing is sold via ToAuto for ₹45,000 and in that too we need to get a step down converter worth ₹12,000 which is the worst thing., as the total investment then would be ₹57,000."
Sonal SahaniNov 2024
WAX MELTER FOR CANDLE MAKING
★★★★★
"Highly recommended for candle making. Convenient to use."
Mohabatti Ki DukaanVerified buyer · Jan 2026
[1 Year Warranty] Mini Electric Wax/Soap Melter (1 litre capacity)
★★★★★
"Soy wax quality is the best, which ever products ordered were properly packed and delivered as early as possible, timely response to the inquiries. Good service"
Jaya SawlaniVerified buyer · Nov 2025
Luxury Soy Wax CSI 464 (Flakes Form) For Container Candles
★★★★★
"Good product"
Biny AbrahamVerified buyer · Feb 2026
Black Glass Jar with Black Lid (150 gram) (Deliveries Starting 5th Dec)
★★★★☆
"Good quality .... if possible delivery date would be try little bit quick please"
Subhankar RoyVerified buyer · Sep 2024
Eco Candle Wicks
★★★★★
"Wax quality are very good"
Sakshi JainVerified buyer · Sep 2026
Luxury Soy Wax Chunks for Jar / Container Candles
Reviews collected and published through Judge.me on candlemakingsuppliesindia.store. They are general reviews of the products named on each card, not assessments of the advice set out below. Wording is unedited.
Shop the Pen Thermometer — ₹354.00 Ask which batch your jars came from
✓ Prices verified 26 September 2026, out-of-stock sizes flagged ✓ GST invoice and MSDS/IFRA documentation on request on WhatsApp ✓ Raw materials only — CSI does not sell finished candles
CSI Jar & Container Guides · Glass Safety
When jars break "at random", the usual reaction is to change the supplier, the wax and the temperature at once, and learn nothing. Here is a split test that changes one thing at a time, a log that shows the answer, and how many jars it takes before you can trust it.
80°C vs 85°C
the two pour arms for CSI 464 in a jar that states 85°C, both inside the stated limits · CSI live pricing, September 2026
Quick answers — read this first
How do I tell a jar-quality problem from a pouring-temperature problem? Change one thing at a time. Test A: jars from the batch that is breaking, poured at two temperatures that are both inside the limits (80°C and 85°C for CSI 464 in a jar that states 85°C). Test B: jars from two batches, poured at the same 80°C. Keep wax, bench, airflow and jar warming identical, interleave the arms on the same tray, and log every jar.

What does the result look like? If the 85°C arm breaks more in both batches, it is your process. If one batch breaks at both temperatures, it is the jars. If breaks are spread evenly, or cluster by time of day or tray position, look at draughts, cold benches, cold jars and chips.

What must I fix before testing? Three things are not test variables: pouring above the jar's stated figure (or not measuring at all), an unchecked thermometer, and chipped jars going into production.

How many jars do I need? More than you think. At an illustrative 2 breaks in 100, a 20-jar arm has about a 67% chance of showing no break at all. Run at least 50 jars per cell per round, inside real production, and keep logging until the pattern is clear.
The short answer
The method: a split test. Batch fixed, temperature changes (80°C vs 85°C). Temperature fixed, batch changes (A vs B at 80°C). Everything else held constant.
The limits: both arms inside the lower of the jar's stated figure and the wax page's range; never test by pouring above either.
The log: jar number, batch and carton, jar storage, wax temperature in the pitcher, surface, airflow, time, tray position, crack yes/no, when, and where it started.
The reading: column heavy = temperature; row heavy = jar batch; no pattern = environment or handling. Rare breakage needs large numbers.
Shop: Pen Thermometer · Steel Pouring Pitcher (Large) · Luxury Soy Wax CSI 464 · Clear 150 g reference jars · Mini Electric Wax Melter
In this guide
Jar batch or pour temperature? Change one thing at a time Same wax, same bench, same airflow, same jar warming. Interleave the arms on the same tray. At least 50 jars per cell per round. Pour at 80°C Pour at 85°C Jar batch A the batch that is breaking Jar batch B another batch or supplier A at 80°C in both tests A at 85°C Test A: temperature B at 80°C Test B: batch B at 85°C optional fourth cell both temperatures are inside the jar's 85°C and CSI 464's stated 80°C – 90°C Test A = top row: batch fixed, temperature changes. Test B = left column: temperature fixed, batch changes. Reading the result: where do the breaks pile up? Column heavy: temperature 85°C breaks more, in both batches: fix the process, pour at 80°C, warm jars Row heavy: jar batch batch A breaks at both temperatures: take the log and photos to the supplier No clear pattern spread out, or clustered by time or tray spot: check draughts, benches, chips Our method, not an industry standard. Rare breakage needs large numbers: keep logging until one pattern is clear, not until the first crack.
Three shaded cells are the minimum: the breaking batch at two temperatures (Test A) and two batches at the same temperature (Test B). The dashed fourth cell completes the square if you have jars to spare. The three small grids show what each answer looks like once enough jars have been logged: dark cells are where the breaks pile up.
Two thermometers · ₹708.00
Pen Thermometer: a temperature test needs a thermometer you have checked
Hold each arm steady · ₹708.00
Steel Pouring Pitcher (Large): a few jars per fill, measured every time
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Ask which batch your last jar order came from
Straight answer
I'm getting random glass breakage in production. How do I separate a jar-quality problem from a pouring-temperature problem?
Stop changing everything at once and run a split test. First remove the things that are not variables: never pour above the jar's stated figure (for the seven CSI jars that state one, "hot-pour up to 85°C"; with CSI 464, whose page states 80°C – 90°C, that leaves 80°C to 85°C), check your thermometer in ice water, and keep chipped jars out of production. Then hold everything else constant (same wax, same jar warming, same bench, same airflow) and change one thing per test. Test A takes jars from the batch that is breaking and pours them at 80°C and at 85°C, alternating on the same tray. Test B takes jars from that batch and from a different batch or supplier and pours both at 80°C. Number every jar and log batch, carton, temperature in the pitcher, surface, airflow, tray position, time, and where any crack started. If the 85°C arm breaks more in both batches, the problem is temperature or process. If one batch breaks at both temperatures, it is the jars. If breaks are evenly spread or cluster by tray position or time, look at draughts, cold benches, cold jars and handling. Breakage that is "random" is usually rare, so you need 50 or more jars per cell and several rounds before a difference means anything.
One line: hold the batch and vary the temperature, then hold the temperature and vary the batch, log every jar, and let the pattern, not a single crack, decide.
A temperature test starts with two thermometers that agree. Two Pen Thermometers cost ₹708.00, and the Large Steel Pouring Pitcher is ₹708.00: the whole split-test kit is ₹1,416.00, in stock on 26 September 2026.
Buy a thermometer — ₹354.00

Fix three things before you test anything

Some causes of breakage are not questions. They are mistakes, and a test only hides them.

A split test compares two ways of working that are both acceptable. It is not a way of finding out whether an unacceptable one is really that bad. Clear these three first, or your result will be noise.

1. Pouring above a stated limit, or not measuring at all

If your jar states a figure, that is your ceiling; if your wax page states a range, stay inside it; the lower governs. Of CSI's container listings, only seven state a figure, "hot-pour up to 85°C" (the 150 g lidded family and the Apothecary Dome Lid jar). If you have been pouring by feel, or straight from a melter, you do not yet have a temperature variable to test. Start measuring, and the "random" breakage may simply stop. The mechanism behind this is covered in why jars crack during cooling; this page assumes you have read it or know it.

2. An unchecked thermometer

A thermometer that reads five degrees low turns every 85°C pour into a 90°C one. Check it in a glass of ice and water, and if you can, run two in the same pitcher. If they disagree, sort that out first. It is a far cheaper answer than a new jar supplier.

3. Chipped and cracked jars reaching the pouring tray

A jar with a chip or hairline fails at its first heat event, and will look like random breakage in any log. Inspect every jar before it is poured, and reject any chip, crack or sharp edge (the reject routine). Count those rejects separately; they are a transit and handling question, not part of this test.

Mistake: switching jar supplier after a bad week, and switching wax and pouring temperature at the same time "to be safe". What actually happens: breakage drops or doesn't, and either way you cannot say which change mattered. When it comes back in winter, you are guessing again. Fix: one change per test, with a log. Changing three things at once is not caution; it is losing the evidence.

The split test, step by step

Run it inside real production if you can. Jars that do not break become saleable candles once your wick and formula are approved for that jar, so the test costs little beyond care and logging. What it needs is discipline: the arms must be poured at the same time, on the same tray, by the same person, in the same air.

1
Identify your batchesMark every carton on arrival with the date received and any lot number printed on it. Batch A is the one you suspect; batch B is a different delivery, a different supplier, or a reference jar. If you bought from us, ask which batch your jars came from.
2
Number and inspect every jarA number on the base, the batch letter beside it, and the 30-second inspection from the reject routine. Only perfect jars enter the test.
3
Fix the constants and write them downSame wax and load, jars stored at room temperature and warmed the same way, the same wooden board, fans and AC off over the tray, windows as usual. Write these at the top of the log sheet.
4
Test A: batch A at 80°C and 85°C, interleavedOdd-numbered jars at 80°C, even-numbered at 85°C, measured in the pitcher, a few jars per fill. Alternate positions on the tray so neither arm always sits nearest the door or the fan. At least 50 jars per arm per round.
5
Test B: batch A and batch B at 80°C, interleavedSame method: alternate batches down the tray, same pour temperature, same timing. The 80°C batch A jars can be shared with Test A; that is the corner of the square both tests use.
6
Check and log at fixed timesLook at every jar at 30 minutes, 2 hours and the next morning. For each crack: jar number, when it was found, where it started (rim, wall, base, at a chip), and a photo. Do not move cracked jars until the wax has set.
7
Repeat, then readRun the same split on more production days until one arm has clearly more breaks than the other, or until several rounds show no difference. Then read the pattern with the table further down.
Optional Test C: jar warmth
If your log hints that cold mornings are worse, add a third split with one batch and one temperature: jars at room temperature against jars warmed until comfortable to hold. It is the same method; only the jar's starting temperature changes.

The log sheet that makes the answer visible

Without a log, every break becomes a story. With one, it becomes a row. Keep it on paper beside the pouring table or on a phone spreadsheet; the columns matter more than the format.

Split-test log · the rows below are illustrative, not data
One row per jar; constants written once at the top of the sheet
Jar Batch / carton Arm Pitcher °C Tray spot Time Crack? Found Origin
A-017 A / carton 2 Test A, 80°C 80 row 2, left 19:10 No — —
A-018 A / carton 2 Test A, 85°C 84 row 2, left 19:11 Yes next morning base ring
B-009 B / carton 1 Test B, 80°C 80 row 2, right 19:12 No — —
A-019 A / carton 3 Test B, 80°C 79 row 3, left 19:14 Yes 30 minutes side facing the door

The illustrative rows show why each column earns its place. A-018 cracked at the base, overnight, in the hotter arm. A-019 cracked on the side facing the door, in the cooler arm, within half an hour. The first hints at temperature or base thickness; the second hints at a draught, not temperature and not the batch. One row proves nothing. Forty rows start to.

Mistake: logging only the cracked jars. What actually happens: you know that 4 jars broke but not out of how many in each arm, so you cannot compare rates. Fix: log every jar, cracked or not. The denominator is half the answer.

How many jars before you trust the result

Random breakage is usually rare breakage, and rare events are easy to misread.

Suppose, purely as an illustration, that your jars break at a steady 2 in 100 under your current routine. Here is how often an arm of a given size would show no break at all, even though the problem is still there.

Worked example · an illustrative 2-in-100 breakage rate, not data
Jars per arm, breaks you would expect, and the chance of seeing none
Jars in the arm Breaks you would expect Chance of zero breaks What that means
20 0.4 67% Most small trials show nothing. A clean result proves little.
50 1 36% One round per cell is a start, not an answer.
100 2 13% Two or three rounds: patterns begin to show.
200 4 2% Now a real difference between arms is hard to miss.

Two lessons follow. First, a tidy 20-jar trial with no breaks does not clear a batch or a temperature. Second, small differences between arms are noise: 2 breaks against 3 means nothing. As a working rule, and it is our judgement rather than a statistical test, treat a difference as real only when it is large (something like 5 or more breaks in one arm against 0 or 1 in the other, over similar numbers of jars) and when the crack origins agree with it. Anything closer is a reason to keep logging, not a reason to change supplier.

That is also why the test should live inside production. A separate trial big enough to mean anything would use hundreds of jars; running the arms alternately through normal runs gets you those numbers for the price of a pen and a sheet of paper.

Reading the result: six patterns

Common patterns · tendencies, not certainties
What the log shows, what it usually points to, and what to do next
Pattern in the log Usually points to Next step
85°C arm breaks more, in both batches Pouring temperature and process Pour at 80°C, warm jars evenly, re-check thermometers; consider a lower-temperature wax with a full re-test
Batch A breaks at both temperatures; batch B does not Jar quality in that batch Stop using batch A for production; take the log, counts and photos to the supplier
Breaks cluster in certain cartons of a batch Transit or handling damage (hairlines you cannot see) Tighten unboxing inspection; photograph cartons; raise packing with the supplier (what packaging to expect)
Breaks cluster by tray position or time of day Environment: a draught, a cold bench, cold jars on cold mornings Fans and AC off, wooden boards, jars warmed; run Test C
Cracks start at the base on heavy-based jars Uneven thickness meeting a cold surface or a hot pour Cool on wood, warm jars fully; see thick base, thin walls and why heavy glass can still fail
Cracks start at small chips or rim flaws Flaws reaching the pouring tray Inspection, not temperature: the chipped-rim reject policy

Sometimes the answer is "both": one batch is more fragile, and your 85°C arm makes it worse. That is still useful. It tells you to fix your process now and to stop buying that batch, rather than hoping one change will do.

Breakage during a burn, rather than during pouring and cooling, is a different investigation; the forensic checklist is in the guide to jars that crack while burning.

Taking a jar-quality result to your supplier

A log turns an argument into a conversation. When your split test points at a batch, send the supplier the numbers per arm and per carton, photos of the crack origins, the constants you held, and the temperatures you poured at. Ask three questions: which batch or lot those jars came from; whether the next delivery will come from the same batch or a different one; and what checks they run on their glass for residual stress and uniformity. Some glass buyers check annealing with a polariscope; that is beyond most small workshops, but it is a fair thing to ask a supplier about.

If the jars came from CSI, send the log and photos on WhatsApp. We would rather see a log than a one-line complaint, because a log lets us check it against the batch, and we will tell you plainly what we can and cannot confirm. For larger programmes where you buy thousands of jars at a time, sampling on arrival is covered in the imported-jar approval guide, and what a supplier's "candle-safe" claim does and does not cover is in the independent-test guide.

Argued against our own interest: when a customer tells us our jars are breaking, the easy answer for a supplier is "it's your pouring temperature", and the easy answer for a maker is "it's the glass". Both are guesses. Run the split. If it points at our batch, we want to know; if it points at your process, you will have fixed something no new supplier could.

What breakage costs, and what the test costs

Worked example, using a 150 g candle at 8% in the Clear 150 g jar (CSI 464 at the 10 kg price, Jasmine Fragrance Oil at the 1 kg price as a stand-in for your oil, an Eco C2 wick): each candle's materials come to ₹220.94. The breakage rate is illustrative.

Worked example · CSI live pricing, 26 September 2026; breakage rate illustrative
The cost of not knowing, against the cost of finding out
Item How it is worked out Cost
Breakage per 100 candles 2 lost candles × ₹220.94 ₹441.88
Breakage across a 1,000-candle festive run 20 lost candles × ₹220.94 ₹4,418.80
Split-test kit Two Pen Thermometers + Large Steel Pouring Pitcher ₹1,416.00, about 32% of that festive loss
Test jars inside production Jars that do not crack become saleable candles once the formula is approved No extra jars
Optional reference arm 40 Clear 150 g jars (two packs of 20) ₹3,776.00

The materials are the smaller part. A cracked jar found at 30 minutes costs a candle; a cracked jar missed at packing costs a customer. Costs exclude labour, freight, packaging and GST.

Diwali is 8 November 2026, 43 days after 26 September 2026. If you are about to pour hundreds of candles, start the split in your first production runs this week, not after the first bad tray; three or four rounds fit comfortably before the festive peak. Ask for jars from a single batch where possible so your Test B has a clean baseline. Get a Diwali quote on WhatsApp with GST invoice and a confirmed dispatch date.
Order the split-test kit
This method is for: workshops pouring dozens to thousands of jar candles a week with breakage that seems to come and go. It is not for: a single cracked jar (inspect, fix the obvious, move on) or cracks during burning (burn cracks). You will need: two batches of jars you can tell apart, two checked thermometers, and the patience to log every jar.

What you need to run it

Ranked by how much each one protects the test from hidden variables: the thermometer first, then the wax you hold constant, the pitcher that keeps each arm at its temperature, a reference jar, and the melter with its warning. Prices and stock verified 26 September 2026.

1
tool · buy two, trust neither until they agree
Pen Thermometer For Candle Making
A split test on temperature is only as good as the thermometer. The page states no range, resolution or accuracy, so check each unit in ice water (close to 0°C) and in boiling water (a little under 100°C at altitude), and run two side by side in the same pitcher: if they disagree by more than a degree or two, you have found a variable before you have started. A thermometer that reads low is a classic source of "random" breakage, because every pour is hotter than the log says. For anyone logging pour temperatures. Limitation: it measures the wax, not the glass.
Pack Price Per unit What it covers
Single ₹354.00 ₹354.00 one pitcher, checked against ice water
Two units ₹708.00 ₹354.00 a cross-checked pair for the split test
Two cost ₹708.00. Buy a thermometer — ₹354.00
2
wax · the test wax, window 80 to 85°C in an 85°C jar
Luxury Soy Wax CSI 464 (Flakes Form) For Container Candles
The page states "Pour Temperature 80°C – 90°C" and "Fragrance Load Up to 10%". In the seven CSI jars that state "hot-pour up to 85°C", the two arms of the split test, 80°C and 85°C, both sit inside the lower of the two figures; that is the reason for choosing them. Do not change wax during a split test: a different wax is a different variable. If your breakage turns out to be temperature, CSI 468 states 58°C – 60°C, but switching wax means re-testing wick, fill and throw. Limitation: 5°C is a narrow window; pour small batches.
Size Price Per gram What it covers
500 g ₹260.00 ₹0.52 3 candles at 138 g of wax
1 kg ₹507.40 ₹0.51 7 candles
5 kg ₹2,537.00 ₹0.51 36 candles: most of one 50-jar cell
10 kg ₹5,074.00 ₹0.51 72 candles
1 kg, 5 kg and 10 kg all work out at ₹0.51 per gram. Buy 10 kg — ₹5,074.00
3
tool · hold the temperature arm steady
Steel Pouring Pitcher (Large, 600 ml)
The page states "Capacity: 600 ml" and "12W x 13H Centimeters". A pitcher you can refill often keeps each pour close to the temperature you logged; a big pot that cools across 50 jars turns an 85°C arm into an 85-to-78°C arm. Pour a few jars per fill, re-measure, and write the reading you poured at, not the one you started at. The Small (150 ml) size is out of stock on 26 September 2026; the Candle Wax Pouring Jug (₹531.00) is an alternative. Limitation: metal loses heat quickly on a cold evening; measure every fill.
Size Price Per unit What it covers
Large (600 ml) ₹708.00 ₹708.00 a few jars per fill, one temperature per fill
Small (150 ml) ₹354.00 ₹354.00 Out of stock on 26 September 2026
Large in stock; Small out of stock. Buy the Large — ₹708.00
4
reference arm · a jar that states a figure
Clear Glass Jar with Golden Lid (150 gram)
If your breaking jar states no pour figure, or you suspect your supplier's batch, a third arm of a different jar poured the same way tells you whether your process breaks good glass too. This one states "Safe for hot pour up to 85°C", one of seven CSI listings with a figure; that is the page's wording, not breakage data, and CSI publishes none. Its black, red, pink and orange versions carry the same wording; amber is out of stock. The page calls the jar both "curved silhouette" and "straight-sided", so treat its dimensions as needing a check. For a reference arm of 40 jars (₹3,776.00). Limitation: a different jar is a different wick test; do not sell reference-arm candles until the wick is approved for it.
Pack Price Per jar What it covers
Pack of 10 ₹944.00 ₹94.40 a small reference arm
Pack of 20 ₹1,888.00 ₹94.40 two packs make a 40-jar reference arm
₹94.40 per jar at either pack size. Buy a pack of 20 — ₹1,888.00
5
melter · useful, with one warning
Mini Electric Wax/Soap Melter (1 litre capacity)
The page's FAQ says Gear I (300W) reaches "approximately 70-85°C" and Gear II (600W) "up to 100-120°C". That second figure is above every jar figure on CSI's store, so a melter left on Gear II and poured from directly is exactly the sort of hidden variable that looks like random breakage. Melt on whichever gear suits you, then decant to the pitcher and measure before every pour. For makers moving from double boilers to steadier melting. Limitation: "approximately" is not a set point; the dial does not replace the thermometer.
Pack Price Per unit What it covers
Single ₹2,360.00 ₹2,360.00 1 litre of melted wax per load
One unit, 1 litre capacity. See the melter — ₹2,360.00
The CSI principle
Change one thing, log every jar, and let the pattern decide.
Pour inside the lower of the two stated limits, hold everything else constant, and wait for a difference big enough to mean something before you blame the glass or the thermometer.
"Random breakage is often not random. It is usually a variable nobody wrote down."
— CandleMakingSuppliesIndia
Why trust this guide

CandleMakingSuppliesIndia sells jars, wax, thermometers, pitchers and melters, and does not sell finished candles. This page tells you our own melter's FAQ gives a Gear II figure above every jar limit on our store, that only seven of our jar listings state a pour figure, and that a split test might point at a batch of our jars. We would rather you find that out with a log than guess.

Every price was verified on CSI's live store on 26 September 2026; every size in a pick table is in stock on that date except the Small pitcher, which is marked out of stock. Temperatures and capacities are quoted from the product pages. CSI publishes no breakage, thermal-shock or batch-quality data for its jars.

The split-test design, the 50-jar minimum, the "5 against 0 or 1" working rule and the pattern table are editorial judgement. The 2-in-100 breakage rate and the log rows are illustrative, and the probabilities are simple arithmetic on that illustration. For bulk pricing, GST invoicing, and MSDS and IFRA documentation on request, message us on WhatsApp at +91 7397976926.

Frequently asked questions

Why are my candle jars breaking randomly in production?
Common causes are pouring above the jar's stated limit or unmeasured, a thermometer that reads low, cold jars or cold benches, draughts from fans or AC, chipped jars reaching the tray, and a weak batch of glass. A split test with a log separates them.
How do I know if my candle jars are bad quality?
Pour jars from the suspect batch and from another batch at the same temperature, interleaved on the same tray, with everything else constant. If the suspect batch breaks clearly more across several rounds, and cracks start in similar places, the batch is the likely cause.
Can pouring wax too hot crack a glass jar?
A hotter pour means a bigger temperature difference across the glass, which is a common cause of cracking. Pour inside the lower of the jar's stated figure and your wax page's range: for CSI 464 (80°C – 90°C) in a jar stating 85°C, that is 80°C to 85°C.
How many jars should I test to find the cause of breakage?
At least 50 per arm per round, repeated over several production days. At an illustrative 2-in-100 rate, a 20-jar arm shows no break about 67% of the time, so small trials prove little.
Should I switch jar suppliers if my jars keep cracking?
Only once a split test points at the jars. Switching supplier, wax and temperature together loses the evidence. Fix limits, thermometer and inspection first, then test batch against batch at one temperature.
What should I record when a candle jar cracks?
Jar number, batch and carton, how the jar was stored and warmed, wax temperature in the pitcher, the surface it cooled on, airflow, tray position, time poured, when the crack was found, where it started, and a photo. Log uncracked jars too.
Jar or temperature, answered
Two thermometers, one pitcher, one log: ₹1,416.00.
Check both thermometers in ice water, number your jars by batch, and run Test A and Test B through your next production days at 80°C and 85°C, interleaved on the same tray. Log every jar. When one pattern is clear, you will know whether to change your process or your batch.
Start with the thermometers Ask which batch your jars came from
Continue the read — glass safety, heat and breakage
Editorial standards & sources
About this guide: a diagnostic split test for random glass breakage in production: the three things to fix before testing, Test A (one batch, two pour temperatures inside the limits) and Test B (two batches, one temperature), a per-jar log, how many jars a rare-event test needs, six result patterns, taking a result to a supplier, and costs.

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 on each card — Black Glass Jar with Black Lid (150 gram) (Deliveries Starting 5th Dec), Eco Candle Wicks, Luxury Soy Wax CSI 464 (Flakes Form) For Container Candles, Luxury Soy Wax Chunks for Jar / Container Candles, WAX MELTER FOR CANDLE MAKING, [1 Year Warranty] Mini Electric Wax/Soap Melter (1 litre capacity). They are general product reviews, not assessments of the container advice on this page. Names, star ratings, dates and products are as recorded by Judge.me and wording is unedited. "Verified buyer" appears only on reviews Judge.me recorded as verified — Mohabatti Ki Dukaan, Jaya Sawlani, Biny Abraham, Subhankar Roy, Sakshi Jain. The reviews from Sonal Sahani are published but not recorded as verified, and carry no badge. Reviews below five stars are included as published, not filtered out.

Figures verified 26 September 2026, CSI live pricing: Pen Thermometer For Candle Making ₹354.00; Steel Pouring Pitcher Large (600 ml) ₹708.00 (Small out of stock); Candle Wax Pouring Jug ₹531.00; Luxury Soy Wax CSI 464 500 g ₹260.00, 1 kg ₹507.40, 5 kg ₹2,537.00, 10 kg ₹5,074.00; Clear Glass Jar with Golden Lid (150 gram), Pack of 10 ₹944.00, Pack of 20 ₹1,888.00 (₹94.40 per jar); Mini Electric Wax/Soap Melter (1 litre) ₹2,360.00; worked-example candle also uses Jasmine Fragrance Oil 1 kg ₹3,923.00 and Eco Candle Wicks Thick (C2) 10 ₹94.40. Per jar = pack price ÷ units; per gram = price ÷ grams, two decimals.

Non-price figures: "hot-pour up to 85°C", CSI 464's 80°C – 90°C, CSI 468's 58°C – 60°C, the melter FAQ's gear temperatures and the pitcher's 600 ml are page wording. The 2-in-100 breakage rate, the 20-candle festive loss and the log rows are illustrative; the zero-break chances are 0.98 raised to the number of jars. Load is a percentage of total candle weight (150 g at 8% = 12 g oil + 138 g wax). Dates are calendar facts. Costs exclude labour, freight, packaging and GST.
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