How Do I Standardise Wax Melting Temperature, Fragrance-Addition Temperature, Mixing Time and Pouring Temperature to Reduce Batch-to-Batch Sweating?

Why the same ingredients sweat in some batches and not others

When one batch is clean and the next shows droplets, and the wax lot, oil lot and weights have not changed, the process is the obvious suspect. In small workshops the process often lives in someone's hands: the wax is "properly melted", the oil goes in "when it looks right", it is stirred "for a bit", and it is poured "when it starts to thicken". Those habits can produce excellent candles. They cannot produce the same candle every time.

Standardising does not mean buying equipment. It means choosing four numbers, writing each one with a tolerance, and measuring them every batch. The table below is a template for that specification.

Set point 1 — melting temperature

Melting is where batches first diverge. A pot melted to a lower temperature may contain wax that is liquid but not fully uniform, while a pot taken well above your usual set point may sit hot for longer and lose more of the lighter fragrance notes once oil is added. Neither is ideal if it differs from batch to batch.

CSI does not publish a melting set point for most of its waxes, so set yours from batches that worked. If you use the CSI Electric Wax Melter, remember that its page states a ±10°C deviation on the display, so a separate thermometer reading in the wax is your real number. The display is a guide, not a record.

Melting has a time element too. A pot that reaches its set point and is used straight away differs from one held hot for an hour while the team finishes another job. Add a maximum hold time at melting temperature to the specification, chosen from your own practice, and record the time the wax reached temperature as well as the time oil went in.

Set point 2 — fragrance-addition temperature

This is the set point most closely linked to sweating complaints. Oil added to wax that is too cool may not incorporate fully; oil added far too hot sits close to its flashpoint and loses volatile material. CSI 400 is one of the few CSI waxes whose page states a window: add fragrance at 80–90°C and stir for 2 minutes.

The oil's published flashpoint is a hard limit that overrides any wax window. Most CSI oils publish flashpoints well above 90°C, but several do not. Neroli's page states 85°C, so in CSI 400 your practical addition window becomes 80°C to just under 85°C. Gardenia's page states 98°C and says to add below 98°C, which sits above CSI 400's window and so does not narrow it. Write the narrower window on the specification sheet for each oil, not one number for the whole range.

Set points 3 and 4 — mixing and pouring

CSI 400's "stir for 2 minutes" is a sensible figure for the batch sizes most makers start with. As batches grow, the same two minutes may not reach the whole mass, and much harder stirring can trap air. Define the mixing set point as a time and a method: for example, "two minutes minimum, slow figure-of-eight reaching the base", then validate it at each batch size you use.

Pouring temperature affects how the candle sets, how it adheres to the glass and how the top finishes. If you use CSI 468, its page gives 58–60°C, which is a ready-made set point. For other waxes, take the pour temperature of your best batches and hold to it. Measure in the pitcher at the first and last pour, because a held pot drifts downward.

Pour temperature and sweating connect through setting. Wax poured well above your usual range stays liquid longer in the jar and sets more slowly; wax poured too cool may set unevenly around the glass. Either can change the surface you see a week later. The specification exists so that the candle you approved and the candle you ship began life at the same temperature.

If your workshop uses more than one wax, each wax needs its own specification sheet. CSI 400's addition window and CSI 468's pour range do not transfer to another wax just because both are soy-based. Keep the sheets separate, label them clearly and keep them where the oil is added, not in an office drawer.

Validating the tolerances

A tolerance only means something if a batch at either edge of it still passes. The way to find out is a small bracketing trial: make candles at the low end and high end of each proposed band, keep everything else fixed, and observe them.

Tolerance trials are small and quick to repeat. If a later batch outside the usual season behaves differently, rerun the bracketing trial for the parameter you suspect rather than widening the tolerance on instinct.

What you need to buy

Standardisation is mostly paper and discipline. The essentials are a thermometer you trust (CSI's Pen Thermometer is ₹354.00; range and accuracy are not published, so check it against a second thermometer before you rely on it), a timer, and stirring tools that reach the base of your pot — CSI's bamboo stirring sticks are ₹1,062.00 for 50. A specification sheet with four lines on it does the rest.

Give the specification sheet an owner: one named person who approves changes to any set point and signs off new tolerances after a bracketing trial. Without an owner, set points drift back to habit within weeks, especially when a busy order pushes people to pour hotter or stir faster.

If after all four set points are controlled you still see sweating, the process is no longer the likely cause. That is the point at which a lower load, then a second wax, deserves testing — and not before. The lower load comes first because it is the cheapest change and frequently keeps the throw intact.

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