Should Every Commercial Candle Formula Have an Approved Maximum Fragrance Load Rather Than Allowing Production Staff to Add Extra Fragrance for “Stronger” Candles?

The well-meant splash

The story is common. A formula passes testing at 8%. A customer says the last candles could be stronger, or a staff member thinks the scent seems faint in the pot, and a little more oil goes in. Nobody writes it down because it feels like a minor adjustment. Weeks later some candles from that run sweat in storage, and the investigation finds nothing wrong with the wax or the oil.

The problem is that the formula that passed testing no longer exists. A load is not a seasoning to be adjusted by feel; it is a tested specification, and the wax's ability to hold oil does not stretch to meet good intentions. If you allow discretionary additions, you have no approved formula, only a starting point that drifts.

What a few extra grams do to the load

Example: a 10 kg batch of CSI 464 with Lavender, approved at 8% of total weight. That is 10,000 × 0.08 = 800 g of oil and 9,200 g of wax. Now add extra oil and recalculate both bases. CSI 464's page states 'up to 10%', and that figure is of wax weight, which is 10 ÷ 110 = 9.09% of total.

The total-basis column divides oil by the new batch weight: 1,000 ÷ 10,200 = 9.80%. The wax-basis column divides oil by wax alone: 1,000 ÷ 9,200 = 10.87%. At +200 g the batch is above CSI 464's stated figure; at +100 g it is already close. And remember that a stated maximum is the wax maker's ceiling for typical oils, not a guarantee for yours. Your approved 8% was chosen because it passed with your oil, which may hold less than the ceiling.

Why extra oil rarely makes a stronger candle

It feels logical that more fragrance means more scent. Up to a point, for some oils, it does. Beyond what the wax holds comfortably, the extra tends to go somewhere other than the air: to the surface as a film or droplets, to the jar edges, or into the wick, where it can contribute to a larger flame, mushrooming or soot. A candle can end up with a stronger cold throw from the oily surface, a hot throw no better than before, and a burn that fails the test the formula originally passed.

That is why CSI, which sells the oil, says plainly: use the load that tested well, not more. If customers want a stronger candle, the levers are a test, not a splash. Check that the wick gives a full melt pool, because a small pool releases less scent. Check that the candles were cured for at least the 48–72 hours the oil page states before anyone judged them. Then, if needed, test a higher load or a different oil as a new formula.

How to set and enforce the approved maximum

Pre-weighing helps more than any instruction. If the batch's oil arrives at the melter in one labelled container holding the approved weight, there is nothing to splash from. If staff pour from the stock bottle at the melter, the bottle is an invitation.

One approved load per scent, not one for the range

An approved maximum belongs to a specific combination: this wax, this oil, this wick, this jar. It does not transfer. If Lavender passed at 8% in CSI 464, that says nothing about a resinous or vanillin-heavy oil in the same wax, which may hold less. Some makers set a single house load for every scent for simplicity. That is workable only if every oil has actually passed at that load; otherwise the house load becomes a quiet licence to run some scents above what they hold.

Put the approved load on each scent's own formula sheet, and make the production schedule pull the load from the sheet rather than from memory. When two scents have different approved loads, colour-code or separate their batch sheets so a 7% scent is not weighed at the 8% of the scent made before it.

The same discipline applies to changes in the other direction. If a scent is approved at 8% and someone decides to save oil by running it at 6%, that is also an untested formula: the throw and the wick behaviour at 6% have not been checked. Lower is often better, and you may well find it is, but it gets approved by testing, the same way as higher.

What the extra oil costs in money and stock

At +200 g per 10 kg batch, Lavender costs an extra ₹1,044.20 per batch. Over an example 20 batches in a season, that is 20 × ₹1,044.20 = ₹20,884.00 of oil that was never tested and may have caused the sweating you are now investigating. Your oil stock also runs out faster than your plan, which leads to rushed reorders or substitutions mid-season, another source of untested changes.

Holding the approved load is therefore a cost control as well as a quality one. It also makes every other diagnosis easier. When a batch sweats and you know the load was exactly what was approved, you can look at process and storage with confidence. When the load might have been anything, you cannot rule it out, and every investigation starts with a guess.

Make the rule visible. Print the approved load, its basis and the oil weight for each batch size on the formula sheet that sits at the melter, and sign off each batch sheet after checking the actual oil weight against it. If the actual weight falls outside tolerance, the batch is held for review before pouring, not corrected by eye. That one habit turns the approved maximum from a number in a file into a control that works on a busy production day.

Where this page fits

CSI already has guides that cover parts of this question. This page answers one sweating decision; these cover the neighbouring questions:

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