My New Oud Fragrance Gives Better Hot Throw at the Same 8% but Also Creates a Deeper Melt Pool — What Should I Retest?

Read the two observations together

Most makers who see this combination celebrate the first half and file the second as a detail. It is the other way round. A deeper melt pool at the same load, wick and jar means the candle is holding more molten wax at the end of each burn. In general candle-making practice that commonly goes with a hotter, more vigorous burn: more heat is going into the pool, the pool is carrying more of it, and more of it reaches the glass. A hotter pool also releases scent more readily — which may be exactly why the new oud throws better. The improvement you like and the change you should worry about can have the same cause.

That does not mean the new oud is unsafe. It means the throw gain arrives with a question attached, and the question is about heat: does the jar get hotter, does the flame get taller, and what happens in the last third of the candle, when the pool is close to the base and there is less glass and wax to absorb the heat? None of that is visible in a first burn. All of it is measurable against your control. These mechanisms are general candle-making knowledge, not measurements of any CSI oil; CSI publishes no burn or throw data for its ouds.

What a deeper pool means in numbers

Geometry is the one part of this you can calculate without testing. Take an illustrative jar with a 7.6 cm internal diameter — use your own measurement; CSI does not publish internal diameters for its jars. The pool surface is π × d² ÷ 4 = 45.36 cm². That area is fixed by the jar: once the pool reaches the edge, the surface releasing scent is the same for both oils. What changes is depth.

If your old oud finished each burn with a pool about 1.0 cm deep and the new one reaches 1.5 cm, the candle is ending each burn with 50% more molten wax — 45.4 cm³ against 68.0 cm³ — at the same surface area. That is the arithmetic of a straight-sided cylinder, not a heat measurement; how much hotter the glass actually runs is something only your thermometer can tell you. But it is a good reason to take the depth seriously. The jar that narrows toward the bottom shows how the same logic gets sharper in a tapered container.

The retest matrix: a throw gain turns into a heat review

The difference from the hub's standard matrix is that end of life has moved from "one pair to the end" to every candle to the end. When the only question is whether a close replacement behaves the same, one full-life pair is proportionate. When you already have evidence of a hotter burn, the late stages are where a problem would be most serious, and six full-life candles are the honest minimum.

The two-stage test

The acceptance rule on every heat line is no worse than the approved control, and within your jar supplier's guidance and the candle fire-safety standard you work to — ASTM F2417 is a commonly cited US standard. CSI publishes no numeric jar-temperature or flame-height limits, so the control is your benchmark and your thermometer is the instrument.

Plan the calendar honestly. Full-life burning on six candles takes as many hours as your candle lasts. You can estimate that from Stage 1's own data: usable wax ÷ grams per hour. As an illustration only, a candle with 180 g of usable wax consuming 6.0 g an hour would last 30 hours — about 7.5 four-hour cycles. Your own numbers replace these.

The priced kit, and what spending the surplus saves

Wicks are your approved wick — the example uses Eco Candle Wicks Thick C2 at ₹94.40 for 10. Buying both stages' oil at once costs ₹1,170.00 against ₹1,300.00 bought separately; the difference is small, and Stage 2 may never be needed, so buy Stage 1 first.

Stage 2 is not only a safety fix; it can also be a saving. White Royal Oud at the 1 kg rate (₹8.10 a gram) costs ₹129.65 per 200 g candle at 8%, ₹113.44 at 7% and ₹97.24 at 6%. If the new oud matches the control's throw at 7% with a heat profile no worse than the control, you save ₹16.21 a candle; at 6%, ₹32.41. The strongest oil is not always the most expensive candle — sometimes it is the cheapest, because it needs less. The cost-at-different-loads post does this comparison between two different oils.

Decision, release and record

Release at 8% only if Stage 1's heat profile is no worse than the control's in every zone and every other line passes; the throw gain is then a genuine upgrade. Release at a lower load if Stage 2 finds one where throw still matches or beats the control and the heat profile matches it. Release with a smaller wick only if load alone did not fix the heat and the new wick passes on pool, heat and throw. Reject the new oud as a substitute if none of those routes gives a heat profile no worse than the control.

Record the result as a formula revision: the new oil's exact listed name, supplier, order date and pack; the load; the wick; the full-life heat profiles for new and control; and the date. Keep the heat-profile sheet with the approved spec — the next time anyone proposes a stronger oil, a hotter wick or a different jar, it is the baseline. Keep a retained sample of the oil lot and two retained candles from the first production batch. If a hotter wick is what someone suggests next, the post on better throw from a more aggressive wick answers it, and the halfway-wick post covers what full-life testing catches that four cycles cannot.

Frequently asked questions