Should My Batch Sheet Record Fragrance-Addition Temperature, Mixing Completion Temperature, First-Pour Temperature and Last-Pour Temperature?

Yes, record all four, and the times beside them

Record all four. Each of the four temperatures answers a different question later, and none of them can be reconstructed after the fact. The fragrance-addition temperature tells you the oil went in where the wax maker and the oil's published flashpoint say it should. The mixing-completion temperature tells you the batch did not cool into a thick, hard-to-mix state before the oil was fully incorporated. The first-pour temperature tells you where the batch started. The last-pour temperature tells you how far it drifted by the end, which is where most long-run problems live.

On their own, four numbers are half a record. Add the clock time beside each one. A last-pour reading of 57°C means one thing after 40 minutes and another after two hours; the time turns a temperature into a hold duration and a drift rate.

What each reading can explain months later

Together the four readings describe the batch's temperature history in a way no single number can. If a complaint arrives, you can see at a glance whether the batch was mixed hot and poured cool, mixed cool and poured cooler, or held for a long time between first and last jar. Each of those points to a different investigation.

Three shapes a batch history can take

Hot start, cool finish. Addition and first pour sit comfortably in range, last pour is at or below the lower edge, and the gap in time is long. This is the classic long-run shape. Suspects: tail candles poured cool, and a long hold for the oil. Test with first and last retained samples.

Cool from the start. The mixing-completion reading is already close to the pour window, so the oil was blended into wax that was thickening. Suspects: uneven distribution through the batch, which can make candles vary at random rather than by pour order. Test with retained samples from several positions, not just first and last.

Flat and short. All four readings are close together and the times span half an hour. The batch history is clean. If candles still vary, look outside temperature: jars, wicks, weighing, or cure before testing. A clean sheet is valuable precisely because it lets you stop suspecting the process and look elsewhere quickly.

A worked batch sheet and the complaint it answered

A maker runs a 15 kg batch in the 20 kg capacity melter: Luxury Soy Wax Chunks with Juicy Orange at 8% of total weight, so 13.8 kg wax + 1.2 kg oil, filling 75 candles of 200 g before losses. The chunks' product page states a maximum fragrance load of 13% of wax weight; 8% of total is well inside it.

The cost, with the working: wax 13.8 kg at the 10 kg pack rate of ₹5,999.00 ÷ 10 = ₹599.90 per kg, so ₹8,278.62; Juicy Orange 1.2 kg as 1 kg ₹7,499.00 + two 100 g at ₹749.00 each (₹1,498.00) = ₹8,997.00. Batch total ₹17,275.62, or about ₹230.34 per candle (₹17,275.62 ÷ 75). With an oil this valuable, a sheet that can clear or convict a batch pays for itself on the first complaint.

Six weeks later a stockist reports that some candles from the batch are weaker than others. The sheet reads as follows; the figures are illustrative for this example.

The sheet does the investigation's first hour for you. Addition and mixing look normal. The last-pour reading is below the window and the gap from first to last pour is over two hours, with one reheat. The late jars also came from a different carton. That is two suspects, not one, and the retained samples let you test them: burn jar 1, jar 38 and jar 75 side by side after equal cure. If jar 75 is clearly weaker, the long hold and cool end deserve a split test before the next batch. If the three match, the complaint may be about something outside the batch, such as storage at the stockist.

The rest of a batch sheet worth keeping

Around the four temperatures, a useful sheet carries a short list of fields. Batch code and date. Wax name and lot, oil name and lot, with target and actual weights and a second person's initials on the oil weight. The thermometer used, identified by a label, so that if it is later found to read high you know which batches it affected. The pouring window in force that day. Hold time from addition to last pour. Reheats, if any, with time, readings and who did them. Jar carton and wick pack references. Operators. Room temperature at start. Retained sample jar numbers. Every one of these is a field someone will wish existed the first time something goes wrong.

Keep the sheet to one page. The more fields it has, the more tempting it is to fill them in at the end of the day from memory, which defeats the purpose. Readings go in at the moment they are taken, in pen. If a reading is missed, write not taken rather than a plausible number; an honest gap is useful information, while an invented figure quietly misleads whoever investigates next. Train new staff on the sheet with a real batch, not a blank form.

Using sheets for prevention, not just defence

Once a month, lay your batch sheets side by side and look at the last-pour column and the hold-time column. If last-pour readings are creeping towards the bottom of the window, or hold times are lengthening as orders grow, you can see drift coming before it shows up in a candle. That is when to shorten batches, add a pourer or split a mix, not after a stockist complains.

If you are building your first sheet and want the oil lot and IFRA or MSDS documents for your records, ask CSI 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:

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