Repeatable Candles

One burn tells you nothing. Two burns tell you what you want to hear. Four burns tell you the truth. The 4-burn protocol is the smallest amount of evidence I trust before I sign a wick off for a range, and it is what every wholesaler I have ever pitched has asked to see.

The worksheet opposite is the exact template I use. One row per burn, five columns per row. If you cannot fill in a cell honestly, you have not run the test, you have watched a candle.

The five measurements

Duration, melt pool depth, mushroom size, flame height, and vessel temperature. Each one catches a different failure mode. Duration proves you honoured the one-hour-per-inch rule from Act 1. Melt pool depth tells you whether the wick is working the wax or overheating it. Mushroom size flags carbon build-up before it becomes soot. Flame height is the fastest read for over-wicking. Vessel temperature is your safety ceiling.

Aim for a melt pool between 8 mm and 12 mm deep by the end of burn three. Flame height 25 mm to 35 mm. Vessel temperature under 80°C at the glass, measured with the probe pressed flat against the outside near the melt line.

Reading mushrooms honestly

A small mushroom at the tip of the wick after a four-hour burn is normal. A mushroom the size of a pea after 90 minutes is not. Under-wicked candles mushroom because the flame cannot draw wax fast enough and starts eating the wick itself. Over-fragranced candles mushroom because the fragrance is thickening the melt pool. The mushroom reference card on this spread shows the four sizes I score against.

Between burns

Trim the wick to 5 mm while the wax is still warm. Wait at least four hours before the next burn so the candle returns to room temperature. If you burn again before it has fully reset, you are testing a hot candle, not a fresh one, and the melt pool will read wider than reality.

The wick that passes four burns in your kitchen is the wick that survives a customer's Sunday afternoon.

Wick selection is where most new makers spend money they did not need to spend. They buy one wick size, it fails, they buy the next size up, it fails differently, and they blame the wax. The matrix on this page is the shortcut I wish I had been given in year one.

Read the matrix, then ignore it

The decision matrix crosses vessel diameter against wax family and drops a starter wick size into each cell. Start there. Do not stop there. The matrix cannot know your fragrance load, your vessel wall thickness, or your room temperature. It gets you within one size, which is close enough to begin testing.

For a 75 mm soy vessel the matrix suggests a CD-12. Buy the CD-10, CD-12 and CD-14. Three sizes, three identical candles, one weekend of testing. That is the three-wick test and it is not optional. Anyone who tells you they picked a wick right first time is either lucky or lying.

Wick anatomy matters

A wick is not a piece of string. It is a braided structure engineered to bend a specific direction as it burns, which pulls the ash away from the flame. That is why CD wicks curl one way and HTP wicks curl the other. Do not mix families mid-range because the burn character will shift and your protocol notes stop being comparable.

The trim ritual

Trim to 5 mm at a slight angle before every burn, including the first. The angle matters. A flat cut mushrooms because the ash has nowhere to fall. A 45-degree cut sheds ash cleanly into the melt pool where it burns off. The trim guide on this spread is annoying to read the first time and second nature after ten pours.

Trim while the wax is still warm from the previous burn. Cold wicks are brittle. They shatter under wick trimmers and leave a jagged base that mushrooms on the next light.

The wick is the failure surface. Everything else is decoration.

Maya Holloway

A vessel is not a neutral container. It is a heat sink, a mechanical support, a legal surface for your CLP label, and, once lit, part of the flame's optical system. Get it wrong and a recipe that passed the 4-burn protocol on the bench will crack, scorch or refuse to throw the moment a customer lights it on a cold windowsill. Every failure surface Act 2 has catalogued so far, the wick above all, is easier to solve once the vessel is right.

Material families and where each one belongs

Container candle vessels fall into six practical families. Soda-lime glass, tempered soda-lime, borosilicate, ceramic (stoneware and porcelain), concrete, and metal (tin-plated steel or aluminium). The single number that matters most across all of them is the thermal shock tolerance, the temperature gradient the wall can absorb without cracking. Annealed soda-lime tolerates roughly a 40°C gradient; tempered soda-lime a little more; borosilicate over 160°C. That is why a cold pour into a room-temperature borosilicate tumbler is forgiving and the same pour into an ice-cold soda-lime jar is a hairline crack waiting to appear on burn three.

Geometry: diameter, headspace, and the shape of the rim

Once the material is chosen, the geometry decides the burn. Diameter sets the melt-pool time (Act 1's one-hour-per-inch rule). Height sets the fuel reserve, but only up to the point where the flame is starved by rim shadowing. Headspace, the vertical gap between the cured wax and the rim, sets the safety margin as the melt pool climbs. Below 12 mm of headspace the flame runs in a hot pocket, the rim scorches, and by burn four you have a returned candle.

Rim geometry is the quiet failure mode. A straight-sided jar vents heat cleanly. A taper vessel, whose inner diameter narrows toward the rim, concentrates radiant heat back onto the shoulder and raises rim temperature by 10–15°C for the same wick. If a taper is unavoidable for the product, drop one wick size from the straight-sided recommendation and re-run the 4-burn protocol against the 80°C wall ceiling.

Wall adhesion, wet spots, and the honesty conversation

Soft container waxes (soy, coconut blends) bond to warm glass on the way down. If the glass is cold, or the wax hits a temperature gradient across the wall, the wax contracts unevenly and leaves the wet spots Act 2's diagnostics section catalogues. Warming the vessel to 35°C before the pour is the single largest lever. Beyond that, wet spots on soy are cosmetic, and the CLP label is the wrong place to apologise for them; a printed insert card in the box that explains natural wax movement earns more trust than a defensive tolerance statement.

The vessel-wick loop

The wick series library in the previous section assumes a straight-sided glass jar. Change vessel material and the wick recommendation moves. Metal vessels shed heat faster and often need one size up. Ceramic vessels retain heat and often need one size down. Concrete needs testing from scratch because the thermal mass reshapes the melt-pool timing entirely. The vessel-wick pair is the unit of testing, not the wick alone. Log both on the batch record together.

The vessel is the silent third wick. Change the glass and you change the flame, whether you meant to or not.

Maya Holloway

Half of what looks like a defect is a signature of natural wax. The other half is a wick or pour problem hiding as a cosmetic complaint. Learning which is which saves you from reformulating a recipe that was already fine.

Why does frosting form on soy candles (and how to prevent it)

Frosting on soy is crystallisation, not a fault. It appears more on candles cooled in a warm room and disappears the moment the surface melts. To reduce it, cool the pour more slowly by warming the vessel and the room to around 22°C before you pour, and avoid moving the candles while they set. To eliminate it completely you need a paraffin blend, which is a wax choice, not a defect fix.

The cosmetic signatures of natural wax you can ignore

Small wet spots on the shoulder of a jar are contraction marks, cosmetic only. Faint jump lines on the glass are where the pour paused for a second while you adjusted a wick. Neither affects the burn. If a customer asks, tell them the truth. Natural wax moves. That is why it is called natural wax.

How to fix soot, heat marks and burn defects

Soot on the glass rim is over-wicking or over-fragranced, in that order. Check the flame height first. If it is above 35 mm, drop a wick size. If it is in range and you still see soot, drop the fragrance load by one percentage point.

Heat marks on the glass, not to be confused with jump lines, look like brown scorching near the rim. This is a real safety issue. The vessel is running above its rated temperature and the glass will eventually fail. Drop a wick size immediately or move to a taller vessel.

The one-variable rule

When you fix a defect, change one thing and re-run the 4-burn protocol. Change two things and you are guessing which one worked. I know it feels slow. It is the only way to build a range you can defend when a customer asks why batch nine burns differently from batch three.

A diagnostic loop that changes one thing at a time takes twice as long and teaches you ten times as much.

Candle formulation is drowning in folklore. Twelve percent is better than ten percent. Coconut throws harder than soy. A pinch of stearic acid fixes everything. Some of that is true in narrow conditions. Most of it is repeated because it sounds like expertise.

This section replaces the folklore with three curves and one matrix. Once you can read them, you can predict a recipe on paper before you pour it.

The load bell curve

Hot throw does not scale linearly with fragrance load. In my own tests it rises from around four percent, tends to peak in the eight to ten percent range for most soy container blends, and then falls as the wax loses the ability to hold and release the extra oil. The curve on this spread is drawn from repeated test-pours in my own workshop, not from a published data set. It is why a candle at twelve percent often throws worse than the same candle at ten.

The peak shifts by wax. In my tests coconut apricot blends have tended to peak a little higher, and paraffin often a little lower, which surprises people. Treat the numbers as a starting point and find the peak for your specific wax and fragrance before you fight them.

Cure curves by wax

Paraffin plateaus at day seven. Coconut blends hit their stride at day ten. Soy is still improving at day twenty-one. If you judge all three at day fourteen, paraffin looks best and soy looks flat. Judge each wax on its own timeline or you will keep choosing paraffin for the wrong reasons.

Wax choice on evidence

The wax comparison matrix scores five common waxes on adhesion, throw, ease of use, cost per kilo, and sustainability. There is no winner. Soy wins on sustainability and loses on speed. Paraffin wins on throw and loses on marketing. Coconut wins on the balance and loses on the price per kilo.

Pick the wax that fits the story you can honestly tell about your brand, then run the load bell for that specific wax. Do not chase the wax an Instagram maker with different economics is chasing.

Nose fatigue is real

You cannot smell your own candles after twenty minutes. The receptors saturate and you start rating everything as weak. The nose fatigue clock on this page is my cheat sheet. Test in the first ten minutes of walking into the room, or after a fifteen-minute break with a cup of coffee. Never test back to back.

Formulation is measurement plus patience. Skip either one and you are guessing in a lab coat.

Wax family library

The matrix below distils the manufacturer TDS values that actually drive a formulation decision. Melt point governs your pour window. Recommended maximum load caps your bell curve. Cure plateau tells you when to judge the candle. Congeal point predicts how quickly the top skins and where you will need a heat gun.

Cure plateaus, in numbers

You do not have to trust the curves on the facing page. The plateaus are documented on the manufacturer sheets. Judge each wax on its own timeline and the wax comparison stops feeling like a personality test.

Scent throw diagnostics

Weak throw is almost never a fragrance-quality problem. It is a wax problem, a load problem, a cure problem, or a wick problem, in that order. Work down the matrix before you email the supplier.

The fragrance is not the recipe. The wax, the load, the cure and the wick are the recipe. Fragrance is what the recipe carries.

Maya Holloway

Everything in Act 2 collapses if you do not write it down. I have watched more talented makers than me reformulate the same recipe three times because they lost the notes on the version that worked. Do not be that maker.

The seven fields that matter

Date, wax lot number, fragrance and load percent, pour temperature, vessel and wick, room temperature, and one free-text line for anything unusual. That is the whole record. Anything more and you will stop filling it in.

The wax lot number is the field beginners always skip and always regret. Wax from the same supplier varies batch to batch. When a recipe suddenly stops working after twelve perfect pours, the lot number is where the answer lives.

Paper first, then the twin

Fill in the paper worksheet on this spread while your hands are already dirty. Transcribe it to the digital twin in the maker log on the same day. The paper copy is the truth if the two ever disagree.

The digital twin at /maker-log/recipes lets you compare batches side by side and flags recipes that drift over time. It is also what you hand a wholesaler when they ask for consistency evidence. A photograph of a handwritten notebook does not carry the same weight as an exported PDF from a dated ledger.

The batch record is boring. The batch record is also the reason candle number ten smells like candle number two.

That closes Act 2. You have a wick you trust, a recipe you can defend, and a paper trail that proves both. Act 3 turns that trust into a price a customer will pay.