Is It Better to Make One 20 Kg Scented Wax Batch or Four 5 Kg Batches When Producing 100 Identical Candles?

Two ways to make the same 100 candles

You want 100 identical candles of 200 g, which is 20 kg of scented wax. You can mix all 20 kg as one batch and pour 100 candles from it, or you can mix four batches of 5 kg and pour 25 candles from each. The fragrance percentage on paper is the same either way. What differs is where variation can creep in.

At 8% of total weight:

One batch: 20 kg scented = 18.4 kg wax + 1.6 kg oil. One weighing of oil. One mix. One pot to keep uniform and in range for 100 pours.

Four batches: each 5 kg scented = 4.6 kg wax + 0.4 kg oil, filling 25 candles. Four weighings of oil. Four mixes. Each pot only has to last 25 pours.

Neither is automatically more consistent. The one-batch structure removes differences between candles caused by weighing, but exposes you to differences caused by time and temperature within the pot. The four-batch structure does the opposite.

The weighing risk grows as batches shrink

Here is the part most makers underestimate. Any weighing routine has some slip: a scale that settles slowly, a drip left in the container, a reading taken a moment too soon. The absolute size of that slip does not shrink when the portion shrinks, so it becomes a larger share of a smaller portion.

Take a hypothetical slip of 10 g on the oil. This is an illustration only; your own slip depends on your scale and routine, and CSI does not publish a resolution for its weighing scale, so measure yours.

On a 5 kg batch, 10 g too little oil gives 390 g in 4,990 g, which is about 7.82%. Ten grams too much gives 410 g in 5,010 g, about 8.18%.

On a 20 kg batch, the same slip gives 1,590 g in 19,990 g, about 7.95%, or 1,610 g in 20,010 g, about 8.05%.

The same mistake moves the smaller batch roughly four times as far. With four batches, you also have four opportunities to make it, and they will not all go the same way. That is how four batches of the same formula can produce two slightly stronger and two slightly weaker groups of 25 candles.

There is a second, quieter effect. With one batch, if the oil weighing is slightly off, all 100 candles are off together, and they still match each other. A customer who buys two will not notice. With four batches, the candles can differ from each other within the same order. For gift sets and corporate orders, where candles are opened side by side, matching each other can matter as much as matching the approved sample. That is a real argument for one batch, and it is why the four-batch route needs a check-weighing habit rather than a single weigher working alone.

The time risk grows as batches get bigger

The one-batch structure has its own weakness. A 20 kg pot takes much longer to pour. Larger masses of wax hold heat longer than small ones, which helps, but the wax is still being drawn down over a long session and needs to be kept both in range and uniform from top to bottom. If the pot is left to stand, the mix can become uneven, and later candles may be poured from wax that has cooled, thickened, or been reheated.

If your team pours 100 candles in a single steady session from a heated pot, stirring gently every few draws and reading the wax with a separate thermometer, one batch is excellent. If the session stretches, breaks for lunch, or depends on reheating, the advantage of a single mix is eroded by what happens to it while it waits.

Side by side

That last row deserves attention. With four batches, a mistake is contained. If batch C is under-scented, you lose 25 candles, not 100. For a new product or a new oil, that containment is worth a lot.

The melter row deserves a caution too. The CSI Electric Wax Melter product page states that it melts 9.5 litres of wax at a time. At roughly 0.9 g per ml, that is about 8.55 kg of liquid wax, which is why a 5 kg batch sits comfortably in the 10 kg unit and a 20 kg batch clearly does not. The page does not give a separate litre figure for the 20 kg capacity, so measure its real fill level before you plan a single 20 kg scented batch around it.

Making four batches behave like one

If your pour rate points you towards four batches, you can recover most of the one-batch advantage with discipline.

Timing matters as well. Four batches do not have to be made hours apart. Schedule them back to back, with the next batch's base already melting while the current one is poured, so all 100 candles are still made in one session, from one set of materials, by one team. That keeps the candles close in everything except the weighing, and the weighing is the part the check-weigh routine above is designed to control.

The decision

Time one real pour. If you can fill all 100 candles within range from a heated, gently stirred pot, make one 20 kg batch. If you cannot, make four 5 kg batches from single lots, with oil pre-weighed, check-weighed and logged under one run code. Either way, retain the first and last candle of the run and compare them after curing.

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