I'm Producing 500 Candles and Want Every One to Contain Exactly the Same Fragrance Percentage — How Should I Structure Weighing and Mixing?

The percentage lives in three places

When makers say every candle should contain exactly the same fragrance percentage, they usually picture careful weighing. Weighing is only the first of three layers, and at 500 candles, each layer can fail independently.

Layer one, batch weighing, sets the percentage. If a batch is weighed at 7.36 kg of wax and 0.64 kg of oil, that batch is 8%.

Layer two, mixing, decides whether every part of that batch is 8%. A batch that is correctly weighed but poorly mixed will produce some candles above and some below.

Layer three, fill weight, decides how many grams of oil each candle actually holds. At 8%, a 200 g candle contains 16 g of oil and 184 g of wax. A candle that is filled to 190 g contains about 15.2 g. The percentage is the same; the fragrance in the jar is not.

Get all three right and every candle is the same. Get one wrong and no amount of care in the other two will fix it.

The 500-candle run, worked through

Five hundred candles at 200 g is 100 kg of scented wax. At 8% of total weight, that is 92 kg of wax and 8 kg of oil. It is not 100 kg of wax plus 8 kg of oil, which would be 108 kg at about 7.4%.

Next, choose a batch module. The CSI Electric Wax Melter (Imported) is sold as a 10 kg unit at ₹21,240.00, and its product page states it melts 9.5 litres at a time. Melted soy wax is roughly 0.9 g per ml, so that is about 8.55 kg of liquid. An 8 kg scented module sits inside that with a little room to stir: 7.36 kg of wax and 0.64 kg of oil, filling 40 candles on paper. Check: 0.64 ÷ 8.00 = 8%.

Now allow the 5% planning wastage. Forty candles less 5% is 38 usable candles per module. 500 ÷ 38 = 13.2, so plan 14 modules. Fourteen modules is 112 kg scented: 103.04 kg of wax and 8.96 kg of oil. The last module will likely be partly surplus, which is better than stopping 20 candles short with a different oil lot.

For oil, 8.96 kg means buying from as few lots as possible. If the scent were Sandalwood, sold at ₹5,026.80 per kg, you would need nine 1 kg units; ask for them from one lot, and record the lot references before the run.

Why not a full 10 kg module, which would make the arithmetic rounder? Because a module is only useful if every one of the fourteen is identical, and a batch that sits at the very top of the vessel is harder to stir the same way each time and more likely to slop when the melter is tilted or drained. A slightly smaller module that fits comfortably is more repeatable than a larger one that only just fits. If your own measured fill level differs from the rough 8.55 kg estimate, change the module to suit and recalculate: the method stays the same whatever the module size.

Structuring the weighing

Keep the weighing station separate

Set the oil weighing up away from the melter and the pouring bench. Heat, vibration from people walking past and drips of wax on the pan all make a scale reading less trustworthy. The station needs the scale, the numbered containers, the run sheet and nothing else. One person owns it for the whole run. When the person who weighs is also the person who pours, the temptation to weigh the next portion in a hurry while a batch waits is what produces slips. Separating the roles removes that pressure entirely, and it makes the second-person check a natural hand-over rather than an extra chore.

Mixing and fill weight

Mixing. Add the oil at the wax maker's stated temperature, read with your own thermometer rather than the melter display, which carries a stated ±10°C deviation. For Eco Soy CSI 400, the stated addition is 80–90°C with 2 minutes of stirring. For waxes without a stated routine, write your own, validate it once by comparing first and last candles, and then make every module follow it. The routine matters more than who performs it.

Do not add oil at the melter's maximum setting. Some CSI oils have published flashpoints below 100°C, including Roasted Coconut at 93°C and Gardenia at 98°C.

Fill weight. Fill every jar on a scale, tared to the empty jar, to 200 g of wax. A tolerance of a few grams either side is a reasonable starting point to validate; the tighter you can hold it, the closer every candle comes to exactly 16 g of oil. Check-weigh a fixed number of finished candles from each module and write the results down.

Reconcile the oil at the end

This is the step most producers skip, and the one that catches the mistakes the others miss.

Before the run, record the oil you have: for example, nine sealed 1 kg units. The plan says fourteen modules at 0.64 kg each will use 8.96 kg. After the run, weigh what is left. If you started with 9 kg and 8.96 kg was planned, about 40 g should remain, plus or minus the small losses of handling.

If far more remains, a module was probably poured without its oil portion, or a container was only partly emptied. If far less remains, a portion was doubled or spilled. Either way, the batch sheet and container numbers tell you which modules to hold back and test. Without the reconciliation, those candles would go to customers.

The decision: fix a module, pre-weigh and check-weigh every oil portion, write the mixing routine down, fill by weight, and reconcile. That is how 500 candles carry the same 8%, and the same 16 g, to every jar.

Where this page fits

CSI already has guides that cover parts of this question. This page takes the production-floor angle; these go deeper on the rest:

Three things to buy for this job

Frequently asked questions