My Candle Produces a Deep Melt Pool Very Quickly — How Do I Determine Whether Excessive Wick Power Is Responsible?

Five things that make a pool deep, and how each one looks

Restating your symptom: the pool reaches a depth you consider deep, commonly more than about 1–1.5 cm (a rule of thumb, not a standard), and it gets there early in the burn rather than near the bottom of the jar. "Deep" and "fast" are different questions: a pool that reaches the glass in record time is 6906's problem, and a pool that only goes deep in the last third is late-burn heat, 6967's. This post is about a pool that is too deep from the first burns, and about proving what is driving it.

Depth is what is left when the heat going into the wax outruns what the jar and air carry away. Five things commonly add to it. None is CSI test data; they are common observations, stated as tendencies.

1. Wick power

A larger or more open wick draws more fuel and makes a bigger flame, which puts more heat into the pool. The signature is depth that keeps rising hour after hour, a flame that grows with it (the pool-depth mechanism, 6902), and depth that falls clearly when you step down a rung, whatever the fragrance.

2. Fragrance load and the oil itself

Fragrance oil is part of the fuel and part of the melt. A higher load, or an oil with heavier, viscous or resinous materials, commonly changes how the wax melts and how the wick draws, and it can push a pool deeper or make a flame smaller and sootier, either way. The signature is a big difference between your scented and unscented candles on the same wick. The two "fragrance changes the wick" questions have their own posts: fine with lavender, huge with vanilla and bigger flame after lowering the load.

3. Room temperature and a warm start

A candle in a hot room, or relit before it has fully set, starts nearer its melting point and can go deeper with the same wick. The signature is depth that changes from day to day with the room, while the gaps between groups burned at the same time stay similar.

4. Draughts and a long wick

A fan or AC vent makes the flame lean and heat one side, so the pool goes deep on that side. An untrimmed wick makes a bigger flame from the start. The signature is a lopsided pool, flicker, and a fix that costs nothing: trim to 5–6 mm and burn in still air before you start counting.

5. Wax and jar

A softer, lower-melting wax liquefies more readily, and a narrow jar has less wax to share the heat. The signature is that everything is deep, even the smaller wick in plain wax. In this test the wax and jar are held constant, so they show up only as that "all four groups deep" pattern.

Six drivers of depth, ranked: burning versus making

The ranking is our judgement for a pool that goes deep early, and it is also the order that wastes least. The two burning causes are removed before the test starts; the 2 × 2 test then separates the making causes.

Causes 3 and 4 are the ones people confuse, because both make the pool deeper on the same candle, and the usual reflex is to wick down for both. That is fine for cause 3. For cause 4 it can leave you with a smaller wick that tunnels in your lighter fragrances. A 7 cm jar that burns perfectly unscented and tunnels at 10% shows the reverse of the same effect.

The 2 × 2 test: one table, four groups, twelve candles

The series default test candle, labelled: 200 g in your jar. Scented candles are 16 g fragrance + 184 g wax at 8% (load as a percentage of total candle weight, inside Luxury Soy Wax CSI 464's stated "Up to 10%" and inside any oil page that states 10%). Unscented candles are 200 g of the same wax, so the fill level stays the same. The worked example assumes your current wick is C2; on Cotton Braided, the rows are Cotton Braided and C2.

Why both scent states? Because a wick effect that shows up in plain wax as well as scented is a wick effect you can trust, and a fragrance effect that shows up on both wicks is a fragrance effect you can trust. The room effect is handled by burning all twelve together: whatever the room does on a given day, it does to every cell, so the gaps between cells stay meaningful. The absolute depths moving from day to day with the logged temperature is the room's signature.

Measuring depth and drawing the depth-per-hour curve

How to measure: dip a clean bamboo skewer straight down to the solid wax at a point midway between wick and glass, hold for a second, lift, and measure the wet length with a ruler. Do it at two marked points on opposite sides, so a leaning flame shows up as a difference rather than an average. Keep the skewer clear of the wick, wipe it between readings, and never tilt or move the jar. It is a labelled practical method, not a lab one, but it is repeatable, and repeatability is what a comparison needs. 6902 has the 30-minute version for flames that grow as the pool deepens.

How to draw it: hour along the bottom, depth up the side, one line per cell (the average of its three candles), and your limit as a dashed line. Then read three things.

In the worked example in the diagram (illustrative), the C2 scented candles climb from 0.7 cm at hour one to 1.8 cm at hour four, a slope of 0.37 cm per hour. The C1 scented candles go from 0.5 to 1.1 cm, 0.20 cm per hour, and flatten. That difference in shape is often clearer than any single reading.

The decision rule, with a worked example

Define two differences from hour-four depth, averaged over sessions two and three. Wick effect = depth on your current wick minus depth one rung down, in the same formula. Fragrance effect = depth scented minus unscented, on the same wick. Then choose a threshold, the smallest difference you will treat as real. Something like 0.3–0.5 cm is a sensible starting point for skewer readings (our judgement, labelled): a difference smaller than your measurement scatter tells you nothing.

Worked example, illustrative: hour-four depths of 1.8 cm (C2 scented), 1.1 cm (C1 scented), 1.5 cm (C2 unscented) and 0.9 cm (C1 unscented). The wick effect is 0.7 cm scented and 0.6 cm unscented, both above a 0.4 cm threshold. The fragrance effect is 0.3 cm on C2 and 0.2 cm on C1, both below it. Verdict: wick power is responsible, the fragrance adds a little, and C1 goes forward. Had the numbers been reversed, with the fragrance moving depth by 0.6 cm and the wick by 0.2 cm, the right first move would have been the load, not the wick. The 10%-and-the-wick-struggles post covers that side of the decision.

The CSI buy list, approval and production

CSI's sized, tabbed wicks are three rungs: C1 → C2 → Cotton Braided. One rung down is Cotton Braided → C2, C2 → C1, or a C2 pair → a C1 pair. There is no sized, tabbed wick between those rungs, no smaller sized, tabbed wick than C1, and one wooden-wick listing with no widths. The braided rolls and the loose wick are cut-to-length constructions, not half-sizes. If your test shows wick power but C1 will not reach the glass, we would rather tell you that than sell a wick that won't fix it: ask on WhatsApp, or take the adjustment on the formula side.

Argued against our own interest: if you already own C2 wicks and holders, the test is ₹1,392.80: one C1 20-pack and the wax. If the 2 × 2 says the formula is driving the depth, you need no wicks at all, only a lower-load retest. And the 5 kg pack of CSI 464 (₹2,537.00, leaving 2,696 g) is no cheaper per gram than the 2.5 kg above, so buy it only if you will use the rest.

Approval: the winner burns to the end

The one-down candidate from cells B and D now needs the full-life test in your scented formula: three candles, 4-hour sessions, trimmed each time, to about 1 cm of wax left (a common rule of thumb), with the top, middle and bottom thirds judged separately. Worked example: at 7 g an hour (your scale decides), 200 g is about 28.6 hours, roughly 7 sessions. The approval rule (ours, labelled): all three candles, in every third, keep pool depth within your limit at hour four, reach the glass by the end of the session from burn two, show no visible smoke, stay within your mushroom limit, and keep the glass under your own written limit, measured, never felt. One fail in any candle fails the candidate. This is an in-house protocol, not an industry standard. If the pool turns deep only lower down, that is late-burn depth, and the cluster hub (6901) has the full one-rung-down plan.

The step to production quantity

Production wicks = candles × wicks per candle × (1 + a defect allowance). Worked example, labelled: 200 single-wick candles a month with a 2% allowance is 204 C1 wicks; 100 + 100 + 20 = 220 cost ₹1,298.00 and leave 16. A 500-pack costs the same ₹5.90 a wick and ties up ₹1,652.00 more. If the 2 × 2 showed a fragrance effect in only some oils, the wick spec splits: in the example, two of five equal-volume fragrances move to C1 (80 candles a month) and three stay on C2 (120). Per-fragrance wicks are normal; write them into your formula sheet. Reorder point = daily use × your lead time + safety stock; CSI publishes no lead times, so ask on WhatsApp.

Four items for the 2 × 2, and what to skip

Four items, chosen on page statements, price and stock on 7 October 2026. CSI publishes no burn, depth or soot data, so nothing here is ranked on performance, and each card says when not to buy.

Skip for now: a new oil "that might burn cooler" before the 2 × 2 tells you the oil is the problem; any 500- or 1,000-wick pack before the full-life test passes; and a different wax mid-test, which would change the constant you are relying on.

Outside this series: a 7.5 cm rose candle at 10% with a very deep pool, asking load or wick first, is the 7.5 cm rose post; a 1 cm pool at hour four and how to judge the heat is the 1 cm at four hours post; fast and extremely deep together is the fast-and-deep wick post; and wicking down without losing throw is large flame, deep pool, excellent throw.

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