My Current Wax Is Cheap but Repeatedly Gives Fragrance-Separation Problems — How Do I Calculate Whether a Better Wax Is Actually Cheaper After Rejects?

Price the candles you can sell, not the candles you pour

When a wax keeps throwing fragrance out of the candle, every sweating jar is a candle you paid to make and cannot sell. A candle that sweats in the stockroom is not for dispatch, whatever the order date, so its full material cost has to be carried by the candles that did pass. That is why the purchase comparison has to be made on cost per good candle, not on the price per kilogram of the wax.

The formula is short: cost per good candle = cost per poured candle ÷ (1 − reject rate). A reject rate of 0.15 means fifteen in every hundred poured candles fail your QC, so each saleable candle carries the cost of 1 ÷ 0.85, or about 1.18 poured candles.

Build the cost per poured candle for each wax

We will use two real CSI prices so the arithmetic is concrete: Eco Soy CSI 400 as the lower-priced wax and Luxury Soy Wax CSI 464 as the dearer one. To be clear, this is a price example, not a claim that CSI 400 causes separation; substitute your own current wax and its price. Both candles are 200 g at 8% of total weight with British Rose, in a matte 200 ml jar with an Eco C1 wick.

For CSI 400 at the 5 kg pack, ₹1,996.00 ÷ 5,000 = ₹0.3992 per gram, so the wax costs 184 × ₹0.3992 = ₹73.45. For CSI 464 at the 10 kg pack, the wax costs 184 × ₹0.5074 = ₹93.36. The oil is the same in both: British Rose at ₹3,068.00 per kg gives 16 × ₹3.068 = ₹49.09. The jar is ₹70.80 from a pack of 10 at ₹708.00, and the wick ₹5.90.

Cost per poured candle with CSI 400: ₹73.45 + ₹49.09 + ₹70.80 + ₹5.90 = ₹199.24. With CSI 464: ₹93.36 + ₹49.09 + ₹70.80 + ₹5.90 = ₹219.15. Both exclude packaging, labels, labour, shipping and GST.

Now apply reject rates

The reject rates below are example figures for the arithmetic. Use your own, counted from your last few batches, not a guess.

Read across, then diagonally. If both waxes give the same reject rate, the cheaper wax always wins. The interesting case is when they differ. Suppose your lower-priced wax is rejecting 15% of candles and the dearer one, in your trial, rejects 3%. Then the comparison is ₹234.40 against ₹225.93, and the dearer wax is cheaper by ₹8.47 per good candle.

Find your break-even reject rate

You can solve for the point where the two are equal. If the dearer wax runs at 3%, its cost per good candle is ₹225.93. The lower-priced wax matches that when 1 − r = ₹199.24 ÷ ₹225.93, which is 0.8819, so r is about 11.8%. Below roughly 11.8% rejects the lower-priced wax is still cheaper; above it, the dearer wax wins. Rework the same sum with your own numbers before you decide.

Make sure the wax is really the cause

This calculation is only fair if the separation is a wax problem. Before you pay more per kilogram, rule out the cheaper fixes that would bring your existing reject rate down without changing wax.

Counting rejects honestly

The whole calculation depends on the reject rate, so decide in advance what counts as a reject and when you count. Otherwise the cheaper wax can look better or worse simply because of when you looked.

A practical definition is any candle that, after your observation schedule, shows an oily, fragrant film on a tissue blot, visible droplets that return after wiping, oil pooled at the edge or around the wick, or wet patches that do not dry. Watery beads that evaporate are moisture, not fragrance, and should be logged separately rather than counted here.

Count at the end of the same schedule for both waxes, for example day 14 plus your supervised warm hold. Counting one wax on day three and the other on day fourteen compares time, not wax. Record the count per batch with the batch's process notes, so that a high reject batch can be traced to a cool addition or a short stir rather than blamed on the wax.

It also helps to separate rejects by cause on your batch sheet: oil on the surface, wet spots, frosting, cracks, wick faults. Only the fragrance-related rejects belong in this wax comparison. A wax change will not fix a crack caused by cooling a jar on a cold steel bench, and counting those rejects against the wax makes the dearer option look more valuable than it is.

Once you have a clean, fragrance-only reject rate for each wax, rerun the table above with your own numbers. If the rates are close, keep the cheaper wax and the money.

The purchase decision

Switch waxes only if, after load and process have been fixed, your current wax still rejects more than the break-even rate you calculated. Then buy the dearer wax in a size that lets you run a full production batch, and count rejects again: the trial rate is a forecast, and only production confirms it.

Using the example figures, a confirmation batch of fifty candles needs 50 × 184 = 9,200 g of wax, which a 10 kg pack of CSI 464 at ₹5,074.00 covers. If production confirms the lower reject rate, larger quantities can be quoted on WhatsApp. If it does not, you have spent one 10 kg pack learning that the wax was not the problem.

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:

Three things to buy for this fix

Frequently asked questions