I Made 10 Kg of Candle Wax at 10% Fragrance Load but Need It at 8% — How Much Unscented Wax Should I Add to Correct the Entire Production Batch?

8% of what? The question that changes the answer by a kilo

A fragrance load is a ratio, and a ratio needs a denominator. Two are in common use among candle makers and both are defensible. The first expresses oil as a percentage of the wax weight — 1,000 g of oil in 10,000 g of wax is 10%. The second expresses oil as a percentage of the finished candle — 1,000 g of oil in an 11,000 g batch is 9.09%. Nothing about the pot has changed; only the sentence describing it has.

This matters here because it changes the size of the purchase. CSI's own wax pages use the wax-weight convention: the Luxury Soy Wax Chunks page states its recommended load as "8% to 13% of total wax weight", with 10% recommended. So if your recipe sheet came off that page, your 10% is 1,000 g of oil in 10,000 g of wax, and 8% is 1,000 g of oil in 12,500 g of wax. You buy 2.5 kg. If instead your 8% meant eight parts oil in every hundred parts of finished candle, the target batch is 12,500 g in total, of which 11,500 g is wax — so you buy 1.5 kg.

This guide does every calculation in the wax-weight convention, because that is the convention CSI's wax pages publish and therefore the one most Indian makers' recipe sheets inherit. Where the other reading gives a materially different number, the tables show both. If you want the mechanics of the two denominators worked from first principles on a single kilo rather than ten, that is the job of the 1 kg version of this problem.

The correction, worked on all 10 kg

Three inputs, one formula, one answer. The formula is the same whether you are 2% over or 6% over, and it is the same at 1 kg and at 100 kg. What changes with scale is how expensive it is to get the first input wrong.

Buying 2.5 kg of the same wax

One rule dominates this purchase: it must be the same wax. Diluting soy chunks with a coconut-soy blend, or a 464 with a pillar wax, produces a third material whose melt behaviour, contraction and fragrance retention nobody has tested — and you will be discovering that in 67 jars at once. Each card shows every listed pack of that wax, the price per kilo, and how many 200 g candles at 8% of wax weight each pack supports on its own.

What 2.5 kg changes downstream

Adding wax does not just lower a percentage. It increases the weight of the batch by 23%, and everything you had planned around 11 kg now has to be planned around 13.5 kg. Here is the whole downstream effect on one costing, using Luxury Soy Wax Chunks and a 1 kg bottle of Lavender Fragrance Oil.

Read the last two rows together, because they are the ones that cost money if you skip them. The correction is cheaper per candle — ₹14.19 less, because the oil is the expensive ingredient and there is now less of it in each jar — but it is cheaper per candle only if you actually pour 67 candles. Pour 13.5 kg into the 55 jars you ordered and you are filling each one to 245 g, which changes the fill depth, the headspace and the burn. Twelve more 120 gm Amber Shiny Glass Jars or twelve more of whatever vessel you are using is not an optional line.

Remelting 13.5 kg: the equipment and the loss you have to measure

At one kilo, "remelt and stir" is a sentence. At 13.5 kg it is a logistics problem, and it is where most of the real cost of this rescue hides. Two constraints bite: what your melting vessel actually holds, and how much wax never makes it into a jar.

On capacity, be literal. The Mini Electric Wax/Soap Melter is listed at 1 litre capacity with dual 300 W and 600 W modes, and its page puts Gear I at approximately 70–85°C and Gear II at up to 100–120°C, noting that "the ideal melting range for most candle waxes is 80–90°C". That is a useful tool for a test pour, not for 13.5 kg. The imported Electric Wax Melter is listed in 10 kg and 20 kg capacities, and its page states it "can melt 9.5 liters of candle wax", melts 10 kg of soy wax in about 30 minutes, and has a display ranging from 60°C to 100°C with a stated ±10°C deviation. Read that deviation figure carefully: it means the number on the display and the number your pen thermometer reads in the wax can honestly differ, and the wax is the one that matters.

On loss, the honest position is that nobody can give you a number for your kitchen. Wax stays behind on the melter wall, in the jug, on the spatula and in the top-up pot, and how much depends on your equipment, your pour temperature and how patient you are with a scraper. What you can do is measure it once and then use your own figure forever: weigh the batch before pouring, weigh every filled jar, and the difference is your loss. The table below shows why the measurement is worth ten minutes.

Correct it, split it or write it off

Dilution is not automatically the right answer. It is the right answer when you have the same wax, the vessels for a bigger batch, and the days to cure and test. When one of those is missing, two other routes are better, and one of them costs nothing at all.

The threshold worth remembering is the ratio in that last row. The correction costs 13% of what the batch is worth in wax and oil alone, before you count the jars, the wicks or your labour. Any rescue that costs under a fifth of the batch's material value and ends in a burn test is a rescue worth running. Above that, start comparing it honestly against repouring — and at 10 kg you are nowhere near that line.

The third route deserves more respect than it usually gets. 10% is not a defect on this wax. The Luxury Soy Wax Chunks page recommends it. If your 8% target came from a costing spreadsheet rather than from a burn test that failed at 10%, the cheapest correct answer may be to keep the batch as it is, price it as a stronger candle, and move your 8% target to the next batch — where it costs nothing to hit. For the case where the load is genuinely over the wax's stated ceiling and sweating in the jar, that is a different problem with a different answer, and the mechanism behind it is in can too much fragrance oil make a candle smell weaker.

The two lines that prevent it

Briefly, because you are mid-rescue and prevention is next week's problem. Both of these are one-line habits, and both would have caught this batch before the oil went in.

First, weigh the oil into a separate container before it goes near the wax. A 10 kg batch at 8% of wax weight needs 800 g of oil; at 10% it needs 1,000 g. Those are two different numbers on a ₹354 scale and one decision at the pot. Pouring straight from the bottle into the melter means the only record of what went in is your memory of how heavy the bottle felt. Second, write the convention and the two weights on the batch sheet before you melt: "wax 10,000 g · oil 800 g · load 8% of wax weight · add 80–90°C · pour 70–80°C". Nine words and two numbers, and the calculation on this page never becomes necessary.

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