My New Wooden Wicks Are Slightly Thicker Than My Previous Shipment — Should I Repeat Full Burn Tests Before Using Them Commercially?

Why thickness matters more in wood than in cotton

A cotton wick draws molten wax up through its braid, and a small difference in how it looks can come from priming wax that burns off in minutes. A wooden wick works differently. It is a thin strip of wood, often laminated or treated, and the flame burns along its upper edge, drawing wax up through the grain and between the layers. The amount of wood presented to the flame, its thickness and width, is one of the main things that decides how big that flame is.

That is why many wooden wick ranges are sold in steps of width or thickness, with each step suited to a different jar diameter. A lot that is consistently thicker than your last one can land you partway into the next step up. The label may be the same; the flame may not.

Thickness also affects rigidity and how the wick sits in its metal clip. A slightly thicker wick can be a tighter fit, which is usually fine, or it can splay the clip so the wick leans. Either way, it is worth checking at goods-in rather than at the pouring table.

Measuring old against new

CSI does not publish width or thickness for its wooden wicks, so for our wicks, and for any supplier that does not publish them, your retained pieces and your own caliper readings are the reference. Ask the supplier directly whether the wood, the thickness or the construction changed between orders, and record the answer.

Rule out the easy explanations first

Before committing a week of attended burning, spend ten minutes ruling out explanations that do not need a burn at all. Put the old and new invoices side by side and compare the product name and any size option word for word; a wider or thicker step picked by mistake is a correction, not a quality issue. Compare the packet labels in the same way.

Then look at the wood itself. Wood takes up and gives off moisture, so a lot that has been stored somewhere humid can swell slightly and read a little thicker on a caliper. Leave both lots on the same dry shelf for a day or two, as a suggested starting point, and measure again. If the gap closes, you were measuring humidity. If it stays, the wicks are genuinely thicker. Damp wood can also crackle and light unevenly, which is another reason to condition a lot before judging it on a burn.

Finally, check that the wood is sound: no splits along the length, no delamination where layers meet, no pieces that snap when flexed gently. Those are defects in their own right, whatever the thickness, and belong in a separate reject count.

A targeted burn to the end

Should you repeat full burn tests before commercial use? If the new lot measures consistently thicker, a burn test is justified. But a full matrix of every jar and oil is usually not the first step. Start where the risk is highest: the jar and fragrance combination in which your current wooden wick already produces the largest flame or the warmest glass. If a thicker wick is going to over-fire anywhere, it will show there.

For wooden wicks, the burn should go to the end, not just a few sessions. Wood wicks can behave well near the top and change character as the pool deepens and the candle narrows the air supply, or as the wick meets the tab area. Pour two old-lot and two new-lot candles from one melt, same oil and load, same jar, same cure. Trim the wood to the same height before each session, burn together on one shelf, attended, and stop any candle that smokes, flares or throws an unusually high flame.

Worked example: a 600 g jar and a 200-candle run

You make 600 g candles in the borosilicate jar CSI lists as a 600 gram fill with gold lid, using Luxury Soy Wax Chunks and Woody Oud at 8% of total candle weight: 552 g of wax and 48 g of oil. You buy wooden wicks in packs of 100.

Four test candles cost 4 × ₹789.94 = ₹3,159.76 in materials. Your next run is 200 candles: 200 × ₹789.94 = ₹1,57,988.00 in materials. The test is about 2% of the run. It also costs several days of attended burning, which is the real price, and still modest beside the cost of pulling a run because the flames are too tall for the jar.

If the new-lot candles match the old, release the wicks for that jar and oil, and consider whether any easier jars can be released on the strength of that result. If they burn noticeably bigger, you have options: hold the lot, ask the supplier, or qualify it for a wider vessel where the extra flame is useful, which is a separate test in its own right.

Release scope and records

Release a thicker wooden wick lot by jar, not as a blanket approval. Your record should show the caliper readings for both lots, the clip-fit check, the burn-to-end log with photos, the supplier's answer, and exactly which jar and oil combinations the lot is approved for. Anything not on that list stays in quarantine until it has its own evidence.

If the wicks were bought from CSI, send your readings and photos on WhatsApp (+91 7397976926); a lot that fails your comparison stays in quarantine whoever supplied it, including us. And add a few pieces of the new lot to your reference card before production uses them up, so the next shipment can be compared against this one.

Where this page fits

CSI already has guides that cover parts of this question. This page covers the goods-in check for the question above; these go deeper on the rest:

Three things to buy for this job

Frequently asked questions