How Do I Calculate the Cost of Remelting, Additional Wax, Labour, Jars and Retesting Before Deciding Whether a Failed Batch Is Worth Rescuing?

Why a rescue needs a full cost sheet

When a batch sweats and the diagnosis points to an oil load above what that wax holds, dilution is the textbook fix: remelt, add unscented wax, pour again at the lower load. Most makers then cost the rescue as the price of the extra wax and stop. That number is real, but it is a fraction of the spend. Dilution grows the batch, so it needs more jars and more wicks. Every candle needs a new wick because the old ones come out with the wax. The lower load can change how the wick behaves, so you may need a second wick size to test. And you will burn and heat-test some of the rescued candles, which means fewer to sell.

This page builds the sheet line by line for one example batch, then turns it into a cost per sellable candle you can compare with remaking. The figures are an example; the structure is what you copy.

The example batch and the dilution maths

Example: 400 candles of 150 g at 10% Bergamot Amber, poured in CSI 468 in clear 150 g apothecary jars with Eco C1 wicks. Testing showed the batch sweats at 10% of total weight. Note that 10% of total is 15 ÷ 135 = 11.11% of wax weight, which is within CSI 468's stated 'up to 13%' (a wax-weight figure) yet still sweated with this oil. A stated maximum is a ceiling for typical oils, not a promise for yours.

Your test candles have already shown 8% holds. Batch weight: 400 × 150 g = 60,000 g, of which oil is 60,000 × 0.10 = 6,000 g. Target batch weight: 6,000 ÷ 0.08 = 75,000 g. Wax to add: 75,000 − 60,000 = 15,000 g. Candles: 75,000 ÷ 150 = 500. Recheck: 6,000 ÷ 75,000 = 8%.

The rescue cost sheet

The materials subtotal: ₹9,555.00 + ₹9,440.00 + ₹2,950.00 + ₹1,300.00 + ₹94.40 = ₹23,339.40. Per sellable candle: ₹23,339.40 ÷ 488 = ₹47.83. Twelve retest candles is a suggested starting point: a few for a day 1, 3, 7 and 14 observation log, a few for your own warm-room hold if you ship in summer, and a few for full burns with C1 and C2. Use your own number, and keep the division honest.

Energy and labour: count them, do not guess them

CSI does not publish power consumption for its melters, and this page will not invent one. What you can count is melts. The Electric Wax Melter page states it melts 10 kg of soy wax in approximately 30 minutes at 100°C; a 75,000 g rescue in the 10 kg capacity melter is 75,000 ÷ 10,000 = 7.5, so eight melts, or four on the 20 kg melter. Scented wax should not be pushed to temperatures you would not normally use, and the melter display carries a stated ±10°C deviation, so check every melt with a separate thermometer.

Multiply melts by your own measured energy per melt. For labour, time a single tray end to end: freeing the wax from the jars, cleaning the jars and inspecting them for chips, remelting, weighing the recovered wax, adding and stirring the fresh wax, re-wicking, pouring, and logging the retest candles. Divide by the candles in the tray and multiply by 500. Some steps, such as the wax extraction, take far longer per candle than a normal pour. That is exactly why they must be measured.

Four ways rescue sheets get under-costed

Pricing wax per gram but buying it in packs. The sheet above works cleanly because 15 kg is exactly one 10 kg and one 5 kg pack of CSI 468. A rescue that needs 12.3 kg still means buying 15 kg at list packs, or a WhatsApp quote for something larger. Cost the packs you will actually buy, and note what is left over for the next batch.

Forgetting that the jar count changes. Makers often order wicks for the original 400 and discover at the pour that the batch fills 500. Order from the diluted candle count, plus a margin for the jars your timed tray showed get damaged during extraction.

Treating retest candles as free. The twelve candles you burn and heat-hold were made from wax, oil, jars and wicks you paid for. They do not appear as a separate spend line because they come from the batch, but they shrink the divisor. Dividing by 500 instead of 488 understates cost per candle.

Adding a 'little extra' oil to compensate for scent lost in remelting. Reheating can drive off some fragrance, but topping up oil blindly raises the load back towards the level that sweated. If the diluted retest candles throw too weakly, that is a finding to act on in the next formula, not a reason to undo the rescue. Any top-up is a new formula and needs its own test candles before it touches the batch.

Turning the sheet into a decision

Now compare with remaking. Both routes need 500 new wicks, the stickers and the 100 extra jars, so those lines cancel. The difference is wax and oil. Remaking 500 candles at 8% needs 500 × 138 g = 69,000 g of wax, costing 69,000 × ₹0.637 = ₹43,953.00, and 500 × 12 g = 6,000 g of oil, costing 6,000 × ₹5.437 = ₹32,622.00. The rescue buys only the 15 kg of wax. The material gap is ₹43,953.00 + ₹32,622.00 − ₹9,555.00 = ₹67,020.00, which is simply the value of the wax and oil already sitting in your failed batch.

Per sellable candle: ₹67,020.00 ÷ 488 = ₹137.34. If your measured extra labour and energy for the rescue come to clearly less than ₹137.34 a candle over a normal production run, rescue. If they approach it, or if your timed tray produced a high jar reject rate, remaking becomes the lower-risk option. Either way, the remake happens at 8%, not 10%: the lower load is the fix, and it needs less oil than the batch that failed.

Whatever the sheet says, a rescued batch earns dispatch only after its retest candles pass. If they sweat, the cost sheet has done its job by stopping you before the full remelt.

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