I Want to Commercialise a 12 cm Three-Wick Candle — How Many Complete Burn Tests Should I Run Across Different Fragrances Before Finalising Production?

Why a 12 cm candle changes the test arithmetic

Small-jar advice on test counts does not transfer. A standard 150 g candle at 8% holds 12 g of oil; the worked-example 700 g candle for your own 12 cm jar (CSI lists none at that size) holds 56 g of oil and 644 g of wax. On a 0.35 cm wall a 12 cm outside is 11.3 cm inside, a 100.29 cm² pool shared by three wicks, and the candle's full life runs to dozens of hours. Every complete burn is several days of supervised sessions and several hundred rupees of material.

That cuts both ways. Testing every oil three times to the bottom is expensive; skipping full-life tests is worse, because a wide three-wick candle commonly shows its problems late: a pool that deepens, flames that grow, glass that heats in the lower third. What large candles reward is screening: a cheap, early pass that removes oils which fail in burns 1–3 before you spend the long tail of the candle on them. The burns that only full life can test (the middle and bottom of the jar) are then spent where they inform the most.

This page assumes the wick build has already been chosen on one oil, as in the identical-or-mixed three-wick post, and that the wick positions are fixed with a template (the placement post). It answers the next question: how much full-life evidence the range needs before production. Bigger matrices with several jars or wick rungs per oil are other posts' territory; here the build and the jar are fixed, and the fragrances vary.

Choosing representative oils on stated attributes

CSI publishes no measured wick data for any oil, so representatives are chosen on what pages state: notes, family, stated candle load, and statements such as vanillin. The three roles are our judgement, chosen because they push a fixed build in different directions.

Why 9% and not 10% for the high-load oil? CSI 464's page says "up to 10%" without stating whether that is of total or of wax weight. Read conservatively on wax weight, 10% is 9.09% of total. 9% of total is 9.89% of wax weight, inside the ceiling either way, so the worked example runs Woody Oud at 9% (63 g oil + 637 g wax per candle). If your highest-load oil runs at a different figure on a different wax, use the lower of the wax page's ceiling and the oil page's stated maximum.

The other five oils in the example are Lavender, British Rose, Bergamot Amber, Eucalyptus Spearmint and Japanese Cherry Blossom, all at 8%. Your range will differ; if it contains both a vanilla and a coffee, pick as "heaviest" the one whose page states the denser profile, and if two oils share the top load, make the heavier of them the representative. Grouping a large range into wick-behaviour families is the fragrance-behaviour groups post.

Candles per oil, and the count it gives

The count follows from two rules (our judgement). Every oil gets two candles on the house build, poured together and screened together; two is the minimum that shows whether one candle was odd. Representatives get a third, poured after the screen passes, because the other oils' approval leans on them. Passing screening candles are not thrown away: they carry on to the stop line, so the screen costs no extra candles, only a pause to read it.

The representative plan saves 85 candle-sessions (340 supervised hours) against "every oil × 3", and it puts each burn where it informs most. The general formula for your own range: complete burns = 3 × R + 2 × (N − R), with R usually 3. For 12 oils that is 3 × 3 + 2 × 9 = 27; for 5 oils, 3 × 3 + 2 × 2 = 13.

Screening rules (judgement). After burn 3, an oil passes if both its candles reach the glass at all six wall points with flames in the common 2.5–5 cm range, depth about 0.5–1 cm, and no heavy carbon caps or soot. An oil whose candles split, or fail in the same direction as another oil, gets a closer look. An oil that fails leaves the plan: its candles stop, and it gets its own two-candle bracket one rung away from the house build, budgeted below. A screen never approves anything; it only decides which candles are worth their long tail. Whether a strong-smelling oil is diffusing or just burning hot is the throw-per-gram post, and it is worth logging grams in the screen anyway: you need them for the clock.

Burn hours from measured grams per hour

Weigh every screening candle before and after each session. Grams lost ÷ hours = grams per hour. In the worked example the 3 × C1 build loses about 36 g in a 4-hour session: 9.0 g an hour. Weigh what is left at the stop line on the first candle to finish (about 90 g in the example), and the candle's burnable grams are 610 g.

Burn rate often rises in the lower third of a wide multi-wick candle (commonly, as heat builds), so the last sessions may run faster than the screen suggested; keep weighing and update the plan. A rate that climbs sharply is itself a finding: the cumulative-heat post reads that trend, and the life-cycle spec post turns the full-life evidence into a spec sheet for the SKU. If your oils differ a lot in burn rate, plan the calendar on the slowest.

Bench, shifts and the calendar

Two limits set the calendar. Per candle: one session a day, with a full cool-down between sessions, so a candle needing 17 sessions needs 17 days. Per bench: the number of positions you can supervise at once, spaced so no flame heats a neighbour, in still air, times the shifts you can run. The worked example assumes 10 positions and two supervised 4-hour shifts: 20 candle-sessions a day. Burn within sight, every session.

On this bench the sequential plan's last result lands on day 33: 1 November 2026 if the first pour is on 29 September. Pouring the third candles on day 0 as well (the parallel plan) brings the last result forward to day 23, but if the house build fails the screen, those three candles, ₹1,925.71 of materials before the jars, were poured on a build you are about to change. Diwali is 8 November 2026, 40 days from 29 September; Christmas is 87 days away. Our honest reading: a festive Diwali launch of a brand-new 12 cm three-wick candle is tight even on the parallel plan once you add a production run after the last result; Christmas is the realistic first season.

The rupee budget

Oil per oil is the candles × grams per candle, bought in the cheapest in-stock combination of bottles that covers it; wax and wicks are pooled. Your jars are not included; CSI lists no 12 cm jar. Costs exclude labour, freight, packaging and GST.

Three grams spare on the 100 g + 15 g pairs is tight: weigh carefully, or swap the 15 g for a 50 g if you want room for a spill. Notice what the cheapest combinations are: small bottles. For a test, the 500 g and 1 kg are rarely the cheaper way to buy 112–189 g, and on several of these oils the 100 g already matches the 500 g per gram (Woody Oud is ₹4.53 a gram at 100 g, 500 g and 1 kg).

Per candle, before the jar, a Dark Vanilla test candle is ₹786.87 and a Citrus Lemon one ₹512.47: the oil choice moves the candle's cost more than the wicks ever will. Argued against our own interest: nothing in this budget needs our biggest packs. The C1 500-pack (₹2,950.00) and multi-kilogram oils are production purchases; buy them after the last full-life result, and ask us for bulk pricing then.

Buying for the commercial test budget

Five items, chosen on page statements, price and stock on 29 September 2026: the pooled wax and wicks, and the three representative oils. The other five oils are in the budget table above; your jars are your own. CSI publishes no wick-performance data, so nothing is ranked on burn results.

Frequently asked questions