I Want My Luxury Candle to Have a Deep Melt Pool but Not Make the Glass Excessively Hot — How Should I Approach Wick Selection?

Why melt-pool depth and jar heat are the same variable

A wick is a fuel pump. It draws liquid wax up to the flame, and the flame returns heat to the wax around it. A bigger wick draws more fuel, burns a larger flame, and returns more heat — which melts more wax, faster, and deeper. Every desirable consequence of a bigger wick and every undesirable one come from the same mechanism. You cannot have the first without some of the second, and a supplier who implies otherwise is selling you a story.

Where that heat ends up is what you are actually choosing between. Some of it goes into melting wax — useful, because the pool is the surface fragrance leaves from. Some goes into the air above the candle — unavoidable. Some goes into the glass, and that is the part that decides whether the candle is safe to sell. The glass then does two things with it: it conducts heat outward to the surface a customer touches, and it stores it, so a jar that felt fine at the end of hour one can feel very different at the end of hour four. This is why a two-hour test is not a test.

Pool depth is the reading that makes this visible earlier than anything else. A wick that is one step too large often reaches the glass at a perfectly reasonable time — you would pass it on width alone — but it does so with a pool that is noticeably deeper than the smaller candidate managed, and that extra depth is stored heat sitting against the wall. Measure it. A steel ruler or a wooden skewer against the rim gives you millimetres, and millimetres are enough to rank two candidates unambiguously.

The four readings, and what each one is actually telling you

Every reading below is something you can take with a ruler, a phone timer and your own hand. None of them requires a laboratory, and none of them is a figure you will find on a product page. Take all four, every hour, on every candidate.

Reading 4 is different in kind from the other three, and it is worth being explicit about why. Readings 1 to 3 produce scores you compare between candidates — this wick against that wick, this hour against that hour. Reading 4 produces a pass or a stop. There is no version of "slightly too hot to hold but it smells wonderful" that turns into a product. An oversized wick or an unsafely hot jar is a hazard, and a candle in that state does not go to a customer regardless of what the other fifteen cells in the grid say.

What CSI publishes about temperature — and what it does not

It is worth laying this out plainly, because the gap in the published information is exactly why this guide is a protocol rather than a recommendation. Here is every temperature figure relevant to this question that appears on a CSI page, and what each one actually governs.

The fourth row deserves a sentence of its own, because it is the most commonly misused number in candle making. A flash point is a property of the neat oil measured in a standard test; it is the basis on which the oil is classified for storage and transport. It is not an instruction about when to add the oil to your wax, and it tells you nothing about the burning candle. The add temperature comes from the wax page — for Eco Soy CSI 400 that is 80–90°C, with 85°C named and a two-minute stir specified. Palo Santo's 93°C is one of only eighteen specific measured values in the CSI fragrance range; thirty-two other pages carry only the shared "> 93°C (suitable for alcohol-based products)" threshold line, which is a classification statement rather than a measurement and should never be quoted as one.

The wick bracket for a 6 cm jar, and what each candidate costs

The bracket is short, and it is short for a reason worth stating: CSI lists two Eco cotton sizes — Thin (C1) and Thick (C2) — plus wooden wicks, and only two wick pages in the entire range state a diameter. Eco Candle Wicks Loose are "designed specifically for 2 inch diameters" — 5.08 cm, close to this jar's 6 cm — and Cotton Braided Wicks Ready Made are for "large-diameter candles exceeding 8 cm", which places them above this build rather than in it. The main Eco Candle Wicks page states no diameter at all.

Start low. Stepping up from a wick that leaves a narrow pool costs you one more batch and teaches you where the ceiling is; stepping down from a wick that overheats the glass costs you a batch you should never have poured and, if you have already sold any of it, a great deal more than that. The asymmetry is the whole argument for beginning at C1 in a 6 cm jar even if your instinct says C2.

The material specification for a 130 g test candle

All load arithmetic here follows CSI's own wording: a percentage of total wax weight, with the finished-candle equivalent given alongside. The jar is deliberately small — a 6 cm diameter and a 130 g fill make the difference between two wick sizes obvious within the first hour, which is exactly what you want from a test format.

The six-candle burn protocol

Six candles: two each of three wick candidates, so every candidate is burned twice — once at day 7 and once at day 14. The second burn is not redundancy. It is how you find out whether a marginal result was the wick or an unfinished cure, which is the misdiagnosis that sends makers back to the wick shelf for no reason.

The costed basket for a six-candle bracket

Priced from live September 2026 listings, rounded to the packs CSI sells, with the leftover valued so you can see what the rounding costs.

Two notes on the arithmetic. The wick lines together come to ₹837.80 — more than a third of the materials subtotal — and you will use six wicks out of forty. That looks wasteful and is not: the leftovers are rounds two and three, and the alternative is guessing. Second, Palo Santo's per-gram price is flat at ₹6.018 from the 100 gm pack up to 1 kg (₹601.80, ₹3,009 and ₹6,018), so there is nothing to gain by buying a bigger bottle for this test — the 15 gm pack at ₹106.20 works out at ₹7.08 per gram and covers barely one candle, and the 50 gm at ₹300.90 is ₹6.018 but leaves no margin for a second round.

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