You Don’t Need a Wick Strategy – You Need A Testing Strategy

It cannot be more plainly stated than this: the only way to know how to choose a wick for your candle is to test burn from absolute start to absolute finish.

That should be the mantra of anyone making candles.  It requires empirical evidence to know if a wick will appropriately serve the combustion machine you’ve so carefully designed.  That being said, I want to provide you with a substantial amount of information on candle wicks to help you on your journey. All the “wick guides” online make it sound so easy and focus so much on the container (which is no doubt huge), but there are so many other factors affecting the burn – all guides should be merely a starting point.

It may seem obvious and intuitive – a wick is meant to be set on fire to “burn the candle”. 

Obviously.  I mean, that’s really all that’s happening at a high level. 

But a deeper dive on this carefully-crafted-cotton reveals how important it is for serving your combustion machine.  If the wax is fuel and the flame consumes that fuel, the wick makes sure the flame is force-fed a steady diet of liquified wax.  Too much and the burn won’t be able to keep up – this shows up as large carbon balls (mushrooming) on the top of the wick. There’s usually a substantial flame and a very hot container.  Too little fuel and the burn will probably die off since it doesn’t have enough fuel. Normally the flame will be tiny (or self extinguish). It’s generally easier to identify an under-wicked candle because of this.

But where do you start when you have to make a candle?  Wick guides? Rules of thumb? I want to talk about what’s really going on with wicks and lay out some research on what all the different wicks are so you can make smart choices going in.

Don’t let anyone tell you “this wick is always the right choice” or “stay away from those wicks, I never use them” because the right wick choice is something you have to determine for yourself.  There are many ways to skin the cat with it, not to mention tons of factors that affect the burn of your candle and a bunch of outcomes you might be targeting for the burn. We’ll talk about those below but let’s start with the major wick types that you might want to buy.  I’ve laid a few common wick types out on a table for easy reference.

Wick Series	Description	Distinguishing Features	Recommended Wax Type
CD	Flat braided cotton with paper in the weave.  Is quite stable despite not having a core.	Rigid, and generally recommended for viscous waxes (vegetables), but works fine in paraffin too	Any
ECO	Similar to CD except the paper is designed to make “self-trimming” more efficient	ECO performs best in lower melt-temp waxes (vegetable)	Vegetable
LX	No core either, and braided uniquely to improve stability and reduce issues with sooting and mushrooming	“Stabilizing threads” that improves flame stability.  Generally recommended for paraffin wax.	Paraffin
HTP	Flat braided weave with “high performance” fibers.  Burns hotter than most other wicks.	Have a tendency to curl for performance – generally towards the “V” side of the braid.	Paraffin
Zinc Core	Actually has a core.  Cotton braid with high stability (due to the core)	Super stable.  Relatively versatile.	Any

Your mileage may vary on these because of how complicated candles can be.  The truth is, almost any wick type will work with your candle. Claims for reducing pollution or increasing performance isn’t entirely misleading, but appropriate sizing of the wick tends to be more important than the actual wick type.

We obviously can’t ignore the relationship between burn temperatures and wax melt temperatures – that’s a fairly easy thing to factor in.  I’m only claiming that worrying so much about selecting the right wick type is secondary to proper testing strategies.

Only by burning a candle with a wick from start to finish (several times) can you ensure your system meets all the performance, pollution, and safety standards you wish to achieve.  The rest is a starting point.

Wicks are generally weaved together with a fiber of some kind (paper, cotton, etc), then chemically treated through a process that coats the wick in a wax.  This ensures proper burn performance of the wick design and is why the wicks have a greasy feel (it’s just wax). The thickness of the wax coating might give the appearance that one wick is thicker than another, but that doesn’t mean the performance will correlate.  If they are different types they will most certainly perform differently.

Most wicks are manufactured by Atkins & Pearce, Technical Braiding, São Vitor or Wedo, so it’s almost certain that if you purchase wicks from a supplier like Candlescience or Lone Star Candle Supply they’re sending you something they bought wholesale from a manufacturer or distributor.

I say all of that to make sure it’s clear that although there are differences in the wick types, the most important part of finally picking a wick for you candle is the performance in your candle, not the recommendation of the wick chart.  Getting started, I recommend using some flavor of the following system for selecting the right wick.

Select a set of preliminary wicks using the wick charts and initial type – or use a sample variety pack.  This is the first step but don’t stress out over this initial decision.  Read around or even use the simple table I have above to figure out where you want to start with wicking.  When you have absolutely no idea, invest in a variety/sample pack for a bunch of wick types and sizes. You should already have some idea of the container you want to use.

Select 3 wick sizes from each type you want to test: one that seems to be right in the recommended “sweet spot” per the manufacturer, and then one on either side of it.  For instance, if CD 10 is recommended for your container (since it is 2.5” in diameter) then I’d also decide to use a CD 8 and a CD 12.

Create candles with no FO or dye.  For every unique wick in your initial testing set, create a test candle in your container using the wax you intend on using, but don’t add anything to it.  No fragrance. No dye. Just wax at your designed temperatures. The intention here is to build a base-line acceptance test for the relationship between wick and wax before we complicate anything.

At least burn twice for 3-4 hours and a super burn to make sure nothing catastrophic happens.  Perform a normal burn test for each candle, and if you made an extra, run a disaster test burn.  Read more about testing later.

Select the winners.  You should have relatively enough data to know the appropriate sized wick for your container.  If none of them meet the criteria, redo the test with a set of wicks up or down (depending on which way the initial test went).

Your wick is usually too big if…

• The candle reached a full melt pool too soon¹
• There’s significant mushrooming at the tip of the wick (5 mm thickness is a good rule of thumb)
• The flame is taller than 3” (though acceptable, 3” is insanely tall too)
• The container temp is too hot (hotter than a fresh cup of coffee is usually too hot)

Your wick is usually too small if it puts itself out, the flame is outrageously tiny, or the candle begins tunneling.

Pour those candles with your formula in it and perform the same burn tests – keep going all the way to the bottom following your normal burn test strategy.  I’m not covering test strategies here, but the next phase is to run the same series of tests with the best performing wicks of the previous steps only with your fragrances and dyes added to the mix.  This is where things get interesting since the wick will be transporting a formula of oil and wax instead of only wax. At this point if a candle begins failing the test it’s okay to abandon ship completely and perform a wickectomy (if you want to keep going) or put it back on the shelf for recycling.

Performance adjustments here are the same as before – watch for the signs during testing and make adjustments accordingly.  Generally speaking, once you have the bare-wax test wick dialed in the final wick in your design will be pretty close. Remember there are a lot of factors that affect performance including (but not limited to):

• Container shape
• Container diameter
• Fragrance Load and quality
• Dye load and quality
• Ambient room temperature
• Worksmanship of the candle
• Conditions of burn area (draft, for example)
• Trim height prior to burn

Want to make millions?  Make a fool-proof calculator for candle wick selection that can account for all factors.  Don’t say I never did anything for you!

¹ Melt pool strategies can vary by designer.  Some like to avoid reaching a full melt pool on the first burn in vegetable waxes that burn down and then out – as it deepens the walls of the container are eventually cleaned by the late-stage burning.  Others like to have a full melt pool at a rate of 1 hour per 1” of diameter, i.e. a 3” diameter container will have a full melt pool in 3 hours.