Two Employees Pour From the Same Batch but Their Candles Look Different — Should I Compare Individual Pitcher Temperatures and Working Times?
Share
What is a swap test? Two employees pour at two stations, then swap halfway through the same batch. The result shows whether defects follow the person, the station or both.
How many candles does the swap test need? A suggested starting point is ten per person per station, forty in all, drawn alternately from one stirred batch.
What if there is no pattern? Then neither person nor station is the main cause. Check jar cartons, wick packs and the order in which candles were poured.
The difference could be the person, the station or the timing
Yes, compare individual pitcher temperatures and working times. Those two numbers explain a large share of operator-to-operator differences. But record them as part of a wider comparison, because a difference between two people is really a bundle of differences: where each of them stands, when in the batch each of them draws, which jars each of them received, how fast each pours, and what each does with a jar after filling it.
If employee 1 always works at the station by the window and always starts the batch while employee 2 finishes it, then person, station and pour order are tangled together. Measuring pitcher temperature alone will show a difference without telling you where it comes from. The design below untangles them with one extra batch.
The worked batch: 20 kg of oud in pearl wax
A workshop mixes 20 kg of scented wax in Natural Soy Pearl Wax with Woody Oud at 8% of total weight: 18.4 kg wax + 1.6 kg oil, filling 100 candles of 200 g, 50 per employee. The Pearl product page does not publish a fragrance load, so this maker validated 8% on small tests before scaling; do the same before copying the figure.
Costs, with the working: wax 18.4 kg at the 10 kg pack rate of ₹4,248.00 ÷ 10 = ₹424.80 per kg, so ₹7,816.32; Woody Oud 1.6 kg as 1 kg ₹4,531.20 + 500 g ₹2,265.60 + 100 g ₹453.12 = ₹7,249.92. The batch is ₹15,066.24 in wax and oil, about ₹150.66 per candle (₹15,066.24 ÷ 100). If half the batch looks second-rate, roughly ₹7,533.12 of material (₹15,066.24 ÷ 2) sits in the doubtful half before jars, wicks or labour.
The complaint: employee 1's candles have smooth, level tops. Employee 2's have a slightly domed centre and small cavities near the wick, and a few show pull-away from the glass.
What to record for every pitcher
Give both employees the same log sheet and a thermometer, and record one line per pitcher. Seconds and degrees matter more than impressions. Every limit you later set from these numbers is a suggested starting point to validate.
| Field | How to record | Why it matters |
|---|---|---|
| Pitcher at fill | Thermometer reading | Sets the starting point for that pitcher |
| Pitcher at last jar | Thermometer reading | Shows the drop within the pitcher |
| Working time | Minutes from fill to last jar | Longer working time, larger drop |
| Pour time per jar | Seconds, timed on two jars | Fast and slow pours set differently |
| Pour height and angle | Low and against glass, or high and centred | Affects air trapping and surface |
| Jar temperature | Warm, room or from a cold store | Cold glass chills the wax at the wall |
| Jar moved after pour | Yes or no, within the setting period | Movement can disturb the top as it sets |
| Station | Name or number | Separates place from person |
Put working time and last-jar reading on one page
Once each employee has logged a dozen pitchers, list them in two columns: working time in minutes and the reading at the last jar. You do not need software. If both employees' points fall on roughly the same line, longer working time simply means cooler wax, and the difference between them is how long each keeps a pitcher going. That is a method issue with an easy limit: fewer jars per pitcher for whoever runs long.
If, at the same working time, one employee's last-jar readings are consistently lower, something at that employee's station is taking heat faster, such as a cold worktop, a draught or a pitcher left on steel between jars. That is a station issue. If the readings match but the candles still differ, temperature is not the story, and pour speed, height or jar handling move to the top of the list. This simple comparison often predicts the swap-test result before the batch is poured, and the swap test then confirms it with candles rather than numbers.
In the worked batch the log showed employee 2 filled larger pitchers, worked each one for about twice as long, and poured quickly from height. Employee 1 poured slowly and low against the glass. Both factors could explain the tops. The next step decides which.
The swap test: two people, two stations, one batch
Run one repeat batch as a small, deliberate experiment. Suggested starting counts to validate: ten candles per cell, forty in all, drawn alternately so both employees pour from the batch at similar points in its life.
| Result pattern | What it points to | Action |
|---|---|---|
| Employee 2's candles differ at both stations | Method: pour speed, height, pitcher size | Write the method down and train both |
| Station Y's candles differ whoever pours | Station: draft, cold surface, jar storage | Fix the station, not the person |
| Only employee 2 at station Y differs | The two combine | Fix the station and the method |
| No consistent pattern | Neither; look at jars, wicks, pour order | Check jar cartons and wick packs |
Pitcher temperature and working time sit behind every row. If employee 2's pitchers ended cooler at both stations because of their size and working time, the method row applies. If station Y's pitchers ended cooler for both employees, the station row applies.
Deciding on the candles already poured
The doubtful half of the original batch is employee 2's fifty candles. Inspect all of them against a written defect list: top level, cavity near the wick, pull-away from glass. Burn three of the worst beside three of employee 1's after the same cure, at least the 48–72 h stated for soy on the product pages. If they burn alike, repair the tops where needed and release. If the cavities affect the burn, hold them and decide between sale as seconds, remelting a small share into a future batch after testing, or writing them off. Keep the decision on the batch record, with the swap-test result beside it, so a customer query months later can be answered from paper rather than memory. The fifty candles from employee 1 can be released on normal checks, since they already match your approved standard.
Make the good method the written method
Whatever the swap test finds, the winning practice becomes a written step with a measurable limit: a maximum pitcher fill, a maximum working time per pitcher, a pour height and speed demonstrated at induction, a rule that jars are not moved during setting, and fixed station layouts. Put the person and station code on every candle base as routine, so the next difference can be traced in minutes rather than argued about for a week. For help choosing which method points to write down first, CSI answers questions on WhatsApp (+91 7397976926).
Where this page fits
CSI already has guides that cover parts of this question. This page covers the failure investigation for the question above; these go deeper on the rest:
Three things to buy for this job
| Option | Price | Status on the September 2026 pull |
|---|---|---|
| Pen thermometer | ₹354.00 | In stock |
| Option | Price | Status on the September 2026 pull |
|---|---|---|
| Large 600 ml | ₹708.00 | In stock |
| Small 150 ml | ₹354.00 | Out of stock |
| Option | Price | Status on the September 2026 pull |
|---|---|---|
| 1 kg | ₹450.00 | In stock |
| 5 kg | ₹2,124.00 | In stock |
| 10 kg | ₹4,248.00 | In stock |
| 50 kg | ₹21,240.00 | In stock |
CANDLEMAKINGSUPPLIESINDIA supplies raw materials and production equipment, not finished candles. This guide separates general process physics from what CSI's own product pages state, and labels every mixing time, temperature window, hold limit, loss allowance or sample count as a starting point for your own validation.
Prices are live CSI prices from September 2026; product pages are authoritative. Where a spec is not published — such as the scale's capacity or the thermometer's range — this guide says so rather than filling the gap.
For bulk quotes, GST invoicing, IFRA and MSDS documents, message us on WhatsApp at +91 7397976926.
Frequently asked questions
- I'm Scaling a 1 Kg Candle Formula to 10 Kg for the First Time — Which Temperatures, Mixing Times and Measurements Should Remain Fixed Rather Than Simply Multiplying Everything?
- My Candle Formula Is Consistent in Small Batches but Inconsistent During Long Production Days — Should I Map Temperature Throughout the Entire Process?
- How Do I Establish an Acceptable Temperature Window Rather Than Requiring Employees to Hit One Exact Number During Commercial Pouring?
- Should My Batch Sheet Record Fragrance-Addition Temperature, Mixing Completion Temperature, First-Pour Temperature and Last-Pour Temperature?
- How Do I Control Temperature Drift Across a 500-Candle Production Run so the First and Last Candles Behave as Similarly as Possible?
- My First 50 Candles From a Large Batch Have Smooth Tops but the Last 50 Are Rough — Is the Wax Cooling Inside My Melter During Production?
- My First Candles Are Poured at 60°C but the Last Ones Are Poured at 52°C — Can This Temperature Drift Explain Differences Across One Production Batch?
- I Start With 20 Kg of Wax at the Correct Pouring Temperature but Production Takes Two Hours — How Do I Maintain Consistent Conditions From First Pour to Last?
- My Wax Melter Keeps Heating While I’m Pouring — Could the Candles Produced Later in the Batch Receive More Thermal Exposure Than the First Ones?
- How to Maintain Consistent Candle Quality as Production Grows
- How to Create a Standard Candle Formula for Commercial Production
Customer reviews: The reviews at the top are genuine, published Judge.me reviews — Thenirvaofficial (5★, verified); Kaushiki Satarkar (5★, verified); Tina Raha (4★, verified); Tanya Walia (5★, verified); Sooraj R (5★, verified); Akansha (4★, verified). Names, ratings, dates and products as recorded by Judge.me.
Product facts (September 2026, CSI live store): Pen Thermometer: Pen thermometer ₹354.00 — range and accuracy not published. Steel Pouring Pitcher: Large 600 ml ₹708.00, Small 150 ml ₹354.00 (out of stock) — stainless steel · 600 ml size 12 × 13 cm. Natural Soy Pearl Wax: 1 kg ₹450.00, 5 kg ₹2,124.00, 10 kg ₹4,248.00, 50 kg ₹21,240.00 — soy-blend container wax in pearl form with a pearlescent finish · no fragrance load published on the product page.
Assumptions: Fragrance load is a percentage of total candle weight (200 g = 184 g wax + 16 g oil at 8%; a 25 kg batch at 8% = 23 kg wax + 2 kg oil). Melted soy wax is taken as roughly 0.9 g per ml for volume conversions, so the melter's stated 9.5 litres is about 8.5 kg — weigh one real fill. Mixing times, temperature windows, hold limits, loss allowances and sample counts are suggested starting points to validate, not measured CSI data. Example logs and readings are illustrations. Prices and availability change — product pages are authoritative.