Can Fragrance Load Affect How Hot a Candle Jar Becomes During a Burn Test?
Aktie
So if my jar runs hot, should I cut the load? Not first. Check the wick size and whether the heat comes in the final third, where jars commonly run hottest whatever the load. Change the load only after a controlled test shows it matters.
How do I test it properly? Ten jars from one pack, one wick size, one wax, one oil: an unscented control plus three jars each at 6%, 8% and 10%. Burn them the same way to the stop-line and log flame height, pool width and depth, and pool temperature after snuffing.
What does the test cost? About ₹2,706.14 at CSI live prices for ten 150 g clear jars, 1.5 kg of CSI 464, 115 g of oil, ten wicks and a thermometer, or ₹2,352.14 if you own a thermometer.
- Straight answer: does load change jar heat?
- How load could change jar heat, and why it is usually the small lever
- Before you test: the two ceilings and the pour limit
- The controlled load test: ten jars, one variable
- Measuring flame and glass warmth without touching a lit candle
- Reading the result: when load is the cause, and when it is not
- What to buy for a ten-jar load test
- What the test costs, and what a load change costs per candle
- Frequently asked questions
How load could change jar heat, and why it is usually the small lever
Follow the heat. A candle flame burns vapour drawn up the wick from the melt pool. Some of its heat goes up and out; some goes into the pool, which widens and deepens; the pool and the flame warm the glass beside them. Glass temperature therefore follows four things: how big the flame is, how close it is to the glass, how long it has been burning, and how much hot wax sits against the wall. Fragrance load can reach only the first of these directly, and only through what the wick is burning.
What a higher load can do at the wick (tendencies, not rules)
Fragrance oils are mixtures of many materials, some lighter and more volatile than wax, some heavier and more viscous. When you raise the load from 6% to 10%, the melt pool carries more of that mixture to the wick. Three things commonly follow, and which one wins depends on the oil. With some oils the flame burns a little taller or brighter. With heavier oils the wick can take up liquid less freely, build carbon on its tip (mushrooming) and run a smaller, duller flame. And past what the wax holds comfortably, oil can separate or sweat at the surface, which can give a flaring or smoky flame. None of these is certain; all of them are reasons to test your oil rather than assume.
Notice that the effects point in opposite directions. That is the honest core of this answer: there is no general rule that "more fragrance means a hotter jar". For one oil in one wax the flame may rise with load; for another it may fall. How load interacts with wick size is covered in our guide on load and wick size, and when more oil stops helping at all is in the too-much-fragrance guide.
What the bigger levers do
| Lever | How it reaches the glass | Size of effect (judgement) | Where to go next |
|---|---|---|---|
| Wick size and type | Sets the flame, and so the heat going into pool and glass | Large: one size up changes the whole flame | Wick by inside diameter |
| Burn stage | In the final third the flame sits lower, nearer the base and the heel of the jar, with hot glass all round it | Large: the same candle runs hotter near the bottom | Why late burns stress glass |
| Inside diameter and shape | A narrow or tapering jar puts glass closer to the flame and the pool reaches it sooner | Large | Jars wider at the top |
| Number of wicks | Two flames, two pools meeting, more heat into the same glass | Large | Two wicks, hotter glass |
| Wick drift | A wick that sets off-centre puts the flame near one wall | Large on one side of the jar | Cracked-jar diagnosis |
| Burn length and draughts | Longer burns soak more heat into the glass; draughts make the flame lean and flicker | Moderate | Very hot on the final burn |
| Wall and base thickness | Changes how heat spreads through the glass and where it concentrates | Moderate, varies by jar | Thick base, thin walls |
| Fragrance load (6 to 10%) | Through the flame only, and in either direction depending on the oil | Usually small; test to find out | This guide |
The ranking is our judgement, not a measurement, and your oil may prove it wrong; that is what the test is for. But it explains a pattern many makers meet: they drop the load from 10% to 8%, the jar is still too hot in the final third, and they lose hot throw for nothing. If your question is really "my jar gets very hot at the end", start with the final-burn diagnosis.
Before you test: the two ceilings and the pour limit
A load test is not permission to push the load. Two stated maximums apply, and the lower one governs. CSI's wax pages state CSI 464 "Fragrance Load Up to 10%", CSI 468 "Up to 13%" and Luxury Soy Wax Chunks "up to 13% fragrance load capacity"; other CSI waxes do not state a ceiling. The oil page adds its own: Woody Oud and Citrus Lemon both say "candles (6-10%)". In CSI 464 with either oil, 10% is the top of the test. These are formulation limits, not regulatory ones, and the maximum is not the target: many candles perform best below it.
The pour has a limit too. The Clear Glass Jar with Golden Lid (150 gram) page says "Safe for hot pour up to 85°C"; CSI 464's page gives a pour temperature of 80°C to 90°C. Read together, pour this wax into this jar at 80 to 85°C. That 85°C is page wording about pouring, stated on seven CSI listings only (the 150 g apothecary-style family and the Apothecary Glass Candle Jar with Dome Lid), and says nothing about how the glass behaves in a burn. The other CSI jar pages use vague wording such as "withstand high heat" with no figure, or say nothing; the glass-suitability hub explains how to read those. Whatever the page says, the burn test is yours to run.
The controlled load test: ten jars, one variable
The design is simple and the discipline is everything. One jar per load tells you almost nothing, because two jars from the same pack at the same load can burn differently: a wick set a millimetre off-centre, a slightly thinner wall, a draught on one side of the table. With three jars per load you can compare the spread within a load against the spread between loads. The unscented control tells you how hot this jar and wick run with no fragrance at all, which is the baseline every other reading is measured against.
Measuring flame and glass warmth without touching a lit candle
The obvious measurement, feeling the glass, is the least reliable and the least safe. Hands are poor thermometers, a burning jar can be hot enough to hurt, and picking one up moves the pool and the flame. Measure what drives the heat instead, and take temperatures in ways you can repeat exactly.
| Measure | How | Why it matters |
|---|---|---|
| Flame height (mm) | Photo against a card marked in 5 mm steps at 1 h, 2 h and just before snuffing | The main heat source. Record the tallest steady height, not a flicker. |
| Soot and mushrooming | Look at the flame tip and the wick top at 4 h; wipe the glass with a white tissue after cooling | A sooting, mushrooming wick is burning more than it should. |
| Pool width | Is the pool at the glass all round at 2 h and 4 h? yes / partly / no | A pool that reaches the glass early means heat is reaching it early. |
| Pool depth (mm) | Straight after snuffing, dip a clean wooden skewer at mid-radius, measure the wet mark | A deeper pool is a larger store of hot wax against the glass. |
| Pool temperature near the glass (°C) | Pen thermometer tip about 5 mm from the glass, within a minute of snuffing, never while lit | Comparable between jars only if taken the same way every time. |
| Glass surface (°C) | Only with a non-contact infrared thermometer you own, aimed at a marked spot 1 cm below the pool line | Optional. CSI does not sell one; flame and pool readings still work without it. |
| Wick position | Distance from wick to nearest wall, by eye against the jar's centre mark | A drifting wick puts the flame near the glass whatever the load. |
| Anything that ends the test | Flame touching glass, a crack, a smoking or flaring flame, a pool reaching the rim | Snuff, let it cool where it stands, record it. Never add water to hot glass. |
Flame height is the reading to trust most
Stand a white card marked in 5 mm steps behind each candle and photograph every flame from the same distance at each checkpoint. It costs nothing, needs no contact and gives you a number to compare across all ten jars. Flame height is the most direct link between load and heat: if it does not change with load, the glass has little reason to either.
Temperatures, taken the same way every time
Readings only compare if they are taken identically. For the pool, snuff the candle, then within a minute put the pen thermometer's tip into the pool about 5 mm from the glass and read it. For the glass itself, a non-contact infrared thermometer aimed at the same marked spot on each jar is the safe tool; CSI does not sell one, and if you do not own one the flame and pool readings are enough to answer the load question. Treat any single temperature as approximate: shiny and clear glass can read differently on infrared thermometers, which is one more reason to compare jars against each other rather than against a number.
Reading the result: when load is the cause, and when it is not
Most tests end in one of six patterns. The first question is always the same: is the difference between loads bigger than the difference between jars at the same load? If not, you have measured jar and wick variation, not a load effect.
| What you see | What it points to | Next step |
|---|---|---|
| All three loads, and the control, run hot in the final third | The jar and wick, not the load | Go to the wick bracket and burn-stage checks; load is not your lever |
| The three jars at one load differ from each other as much as the loads differ | Jar-to-jar and wick-to-wick variation | Load has no effect you can see; look at wick centring and glass batch |
| Flame height rises steadily from 6% to 10%, and pool temperature follows | A real load effect for this oil in this wax | Use the lowest load whose hot throw satisfies you, then re-run the final third |
| Flame height falls at 10%, with mushrooming or a weak flame | The wick struggling with the oil at that load | Drop the load; this is a wick-and-oil question, not a glass one |
| The control (0%) runs hotter than the scented jars | The wick is on the large side for this jar even unscented | Re-bracket the wick; fragrance was masking, not causing, the heat |
| Only one jar runs hot | That jar or that wick: drift, a tilted wick, a thin or flawed wall | Inspect it, set it aside, and do not count it as a load result |
Two cautions. First, a load effect found with Woody Oud does not transfer to Citrus Lemon, or to any other oil; the materials differ. If your range spans very different oils, repeat the grid with the heaviest and the lightest, which is what the two-oil version costs extra for. Second, a lower load that runs cooler is not automatically the better candle: it may throw less, which is why the decision belongs with your hot-throw notes as well as your heat log. How to find the lowest load that still throws well is covered in the fragrance-load posts of our earlier series.
What to buy for a ten-jar load test
Five items, chosen on what their pages state, price and stock on 26 September 2026, not on burn performance: CSI publishes no burn or glass-temperature data for any of them. Wicks are the sixth ingredient, and you should use the size your bracket already chose; the Eco Candle Wicks are ₹5.90 (C1) and ₹9.44 (C2) each in packs of 10.
| Pack | Price | Per jar | What it covers |
|---|---|---|---|
| Pack of 10 | ₹944.00 | ₹94.40 | one full load test: 1 control + 3 jars at each of 6%, 8% and 10% |
| Pack of 20 | ₹1,888.00 | ₹94.40 | the two-oil version of the test, or the test plus a retest |
| Size | Price | Per gram | What it covers |
|---|---|---|---|
| 500 g | ₹260.00 | ₹0.52 | tops up the 1 kg to cover the test |
| 1 kg | ₹507.40 | ₹0.51 | seven 138 g candles; pair with 500 g for the ten-jar test |
| 5 kg | ₹2,537.00 | ₹0.51 | the test plus a production trial |
| 10 kg | ₹5,074.00 | ₹0.51 | production once the load is chosen |
| Size | Price | Per gram | 150 g candles at 8% |
|---|---|---|---|
| 15 gm | ₹93.22 | ₹6.21 | 1 |
| 50 gm | ₹271.40 | ₹5.43 | 4 |
| 100 gm | ₹453.12 | ₹4.53 | 8 |
| 500 gm | ₹2,265.60 | ₹4.53 | 41 |
| 1 kg | ₹4,531.20 | ₹4.53 | 83 |
| Size | Price | Per gram | 150 g candles at 8% |
|---|---|---|---|
| 15 gm | ₹81.42 | ₹5.43 | 1 |
| 50 gm | ₹170.00 | ₹3.40 | 4 |
| 100 gm | ₹300.00 | ₹3.00 | 8 |
| 500 gm | ₹1,420.00 | ₹2.84 | 41 |
| 1 kg | ₹2,832.00 | ₹2.83 | 83 |
| Pack | Price | Per unit | What it covers |
|---|---|---|---|
| Single | ₹354.00 | ₹354.00 | pool temperature after snuffing, and pour temperature at 80 to 85°C |
What the test costs, and what a load change costs per candle
| Item | Buy | Price | Role in the test |
|---|---|---|---|
| Clear Glass Jar with Golden Lid (150 gram) | Pack of 10 | ₹944.00 | 1 control + 3 jars × 3 loads, one batch |
| Luxury Soy Wax CSI 464 | 1 kg + 500 g | ₹767.40 | 1,392 g of wax, plus a little for pitcher loss |
| Woody Oud Fragrance Oil | 100 g + 15 g | ₹546.34 | 108 g of oil across nine scented jars |
| Eco Candle Wicks, the size your bracket chose (C2 shown) | 10 wicks | ₹94.40 | One wick size in every jar |
| Pen Thermometer For Candle Making | 1 | ₹354.00 | Pour at 80 to 85°C; pool temperature after snuffing |
| Total | ₹2,706.14 | ₹2,352.14 without the thermometer |
Two notes on buying. The Woody Oud's 100 g, 500 g and 1 kg all cost ₹4.53 per gram, so there is no saving in buying big before the test; and two 50 g packs plus a 15 g would cost ₹636.02 for the same 115 g, more than 100 g + 15 g. Swap in Citrus Lemon and the kit is ₹2,541.22; run both oils (twenty jars; the two grids need 2,784 g of wax, so three 1 kg packs) and it is ₹4,880.76. The test itself burns about ₹2,234.07 of material; the thermometer and the spare wax stay with you.
What the load you choose costs in production
The reason to know whether load affects heat is that load also affects cost. Worked example, one 150 g candle in this jar with CSI 464 at the 10 kg price, Woody Oud at the 1 kg price and a C2 wick, excluding labour, freight, packaging and GST:
| Load | Oil | Wax | Jar | Wick | Total |
|---|---|---|---|---|---|
| 6% | 9 g · ₹40.78 | 141 g · ₹71.54 | ₹94.40 | ₹9.44 | ₹216.16 |
| 8% | 12 g · ₹54.37 | 138 g · ₹70.02 | ₹94.40 | ₹9.44 | ₹228.24 |
| 10% | 15 g · ₹67.97 | 135 g · ₹68.50 | ₹94.40 | ₹9.44 | ₹240.31 |
Moving from 6% to 10% adds ₹24.14 per candle with Woody Oud, ₹2,414.28 per hundred; with Citrus Lemon at its 1 kg price the same move adds ₹13.95 per candle. Small sums per candle, real sums per batch, and wasted entirely if the extra oil did not improve the throw and the heat problem was the wick all along. The cost side of load changes is covered fully in I Changed My Fragrance Load From 6% to 10% — Will That Change How Much Wax I Need to Put Into Each Jar?.
CandleMakingSuppliesIndia sells the jars, wax, oils, wicks and thermometer named here, and does not sell finished candles. This guide tells you that fragrance load is usually a small lever on jar heat, which means selling you less oil, and that the only numeric heat wording on our jar pages is about pouring, not burning. We publish no burn-down, thermal-shock or glass-temperature data, and say so.
Every price, per-gram and per-jar figure was verified on CSI's live store on 26 September 2026; every size shown in the pick tables was in stock that day, and the one out-of-stock member of the 85°C family, the amber 150 g jar, is left out. Load ranges, pour temperatures and heat wording are quoted from the product pages.
The ranking of heat levers, the three-jars-per-load design, the 10 cm spacing and the reading table are editorial judgement from general candle-making practice; the 4-hour cycle and 1 cm stop-line are common practice; the per-candle costs are worked examples. For bulk pricing, GST invoicing, and MSDS and IFRA documentation on request, message us on WhatsApp at +91 7397976926.
Frequently asked questions
- I Found Attractive Glass Jars Online — How Do I Know Whether They Are Actually Suitable for Burning Candles?
- How Do I Test a New Glass Candle Jar for Heat Safety Before Ordering 500 Pieces?
- My Candle Jar Becomes Very Hot During the Final Burn — Is the Jar Unsafe or Is My Wick Too Large?
- My Glass Candle Jar Cracked While Burning — How Do I Determine Whether the Problem Was the Glass, Wick or Uneven Heating?
- Can a Candle Jar Survive Early Burn Tests but Still Crack When the Candle Burns Closer to the Bottom?
- Why Is Testing the Final Third of a Candle Important Before Approving a New Glass Container for Commercial Sale?
- My Candle Uses Two Wicks and the Glass Gets Much Hotter Than My Single-Wick Candle — Should I Change the Jar or Wick Configuration?
- My Jar Has a Very Thick Base but Thin Side Walls — What Should I Watch for During Candle Burn Testing?
- What Jar Safety Tests Should a Small Candle Brand Complete Before Buying and Selling a New Container Commercially?
- I Changed My Fragrance Load From 6% to 10% — Will That Change How Much Wax I Need to Put Into Each Jar?
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 — Citrus Lemon Fragrance Oil, Clear Glass Jar with Golden Lid (150 gram), Eco Candle Wicks, Luxury Soy Wax CSI 464 (Flakes Form) For Container Candles, Woody Oud Fragrance Oil. 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 — Payal Patel, Renam Dhoundiyal, Avanthi Cheeli, Thenirvaofficial, Soumili Gope, Monika Deep. Reviews below five stars are included as published, not filtered out.
Figures verified 26 September 2026, CSI live pricing: Clear Glass Jar with Golden Lid (150 gram) Pack of 10 ₹944.00, Pack of 20 ₹1,888.00 (₹94.40 per jar); Luxury Soy Wax CSI 464 500 g ₹260.00, 1 kg ₹507.40, 5 kg ₹2,537.00, 10 kg ₹5,074.00; Woody Oud Fragrance Oil 15 g ₹93.22, 50 g ₹271.40, 100 g ₹453.12, 500 g ₹2,265.60, 1 kg ₹4,531.20; Citrus Lemon Fragrance Oil 15 g ₹81.42, 50 g ₹170.00, 100 g ₹300.00, 500 g ₹1,420.00, 1 kg ₹2,832.00; Eco Candle Wicks Thin (C1) 10 ₹59.00, Thick (C2) 10 ₹94.40; Pen Thermometer For Candle Making ₹354.00. Kit totals, per-candle costs and load-change costs are declared calculations.
Non-price figures: 150 g candle on a total-weight basis (6% = 9 g oil, 8% = 12 g, 10% = 15 g); CSI 464 "Fragrance Load Up to 10%" and "Pour Temperature 80°C – 90°C"; CSI 468 and Luxury Soy Wax Chunks up to 13%; Woody Oud and Citrus Lemon "candles (6-10%)"; "Safe for hot pour up to 85°C" quoted from the jar page and stated on seven CSI listings; the 4-hour cycle, 1 cm stop-line and 48–72 hour minimum cure are common practice or page wording as labelled; the lever ranking, spacing and reading framework are judgement; Diwali 8 November 2026 is a calendar date.