Should I Ask My Soy Wax Supplier for a Batch or Lot Number so I Can Trace Production Problems Back to Incoming Raw Material?

Yes — and when the supplier has none, make your own

Ask every wax supplier the same question: do you mark a batch or lot number on the bag, and will it appear on the invoice? If the answer is yes, write it into your records with everything else. If the answer is no — and for CSI it is no; we publish no lot numbers, certificates of analysis or change notices for our waxes — that does not end the conversation. It means the lot number has to be yours. A lot label you write on each bag the day it arrives does almost everything a supplier lot number would do inside your workshop: it ties each candle back to one delivery.

The reason this matters is narrow and practical. When a batch fails — rough tops, weak throw, a candle that tunnels, sweating after a hot week — you need to know which wax was in it. Without a label, every bag bought in the last few months is a suspect, and so is every candle made from them. With a label, the batch sheet names one delivery, your retained sample from that delivery sits in a drawer, and you can pour three candles from it beside three from your current wax to see whether the wax is the cause. That is the whole system: label, record, retain, and test when something goes wrong.

This page builds that system for a small Indian candle business: what to ask the supplier, how to write your own lot code, how to carry it through the batch sheet onto the candle, what to retain, and the three-plus-three traceback test that turns the label into evidence. Retained samples and the delivery record each get their own post; this one is about the label that links them.

What to ask the supplier, and what to create yourself

The lead table separates the information only the supplier can give from the information only you can create. Ask for the first column in writing; build the second whatever the answer.

Look at the last three rows. Even a supplier who prints lot numbers on every bag cannot tell you which bag went into which batch, which batch ended up in which candle, or keep a sample of your delivery for you. Those three links are always yours, and they are the ones a complaint actually needs. That is why the honest answer to the title is yes, ask — and then do not wait for the answer before labelling.

How to write your own lot code

A good lot code is short enough to write on a bag with a marker, unique for every delivery, and readable by anyone in your workshop without a key. The format below works for a small business; change the letters, but keep the structure the same for every material so nobody has to guess.

What the label is worth when something goes wrong

Take an example maker who buys 50 kg of Natural Soy Pearl Wax at a time and has taken 4 deliveries since February. Each delivery makes about 271 candles of 200 g at 8% (184 g of wax each). In May a batch shows a fault and the maker suspects the wax. Without lot labels, any of the four deliveries could be the cause, so every candle made since February is a suspect. With labels, the batch sheet names one delivery.

Those are candles you would have to hold, inspect, or in the worst case withdraw. The material figure is at ₹203.95 per candle and excludes labour, packaging, freight and GST, so the real exposure is larger. Against it, the label is a marker pen, and the retained sample is 600 g of wax — ₹254.88 of Natural Soy Pearl at ₹424.80 a kilo, or ₹359.40 of Luxury Soy Wax Chunks. At an example two deliveries a month, a year of Soy Pearl retained samples ties up ₹6,117.12 of wax, which you can still use once its retention period ends.

The traceback test: is the wax the cause?

When a batch fails, the label lets you run a clean comparison instead of guessing. The test pours candles from the retained sample of the suspect lot beside candles from your current approved wax (or a retained sample from a delivery you know was good), with one fresh oil lot, the same wick and jar, on the same day. If the suspect-lot candles reproduce the fault and the control candles do not, the wax delivery is the most likely cause. If both reproduce it, look at the oil, the process or the conditions. If neither does, the fault came from something that happened in that batch, not the wax.

Waxes in the example, and how pack size affects labelling

Pack size changes how fine your traceability can be. A 50 kg bag is one lot label for 50 kg of production; five 10 kg bags from the same delivery share a lot code but can be numbered and opened one at a time. Neither is better as a fact — it depends on how fast you use an opened bag and how you store it — but it is worth deciding deliberately.

The decision rule: how much traceability your business needs

For the example maker the concrete answer is: ask CSI on WhatsApp for the MSDS and available documentation, keep buying Natural Soy Pearl Wax in 10 kg bags (₹4,248.00 each) so each bag carries its own number under one delivery code, seal 600 g from every delivery, and write lot codes on every batch sheet from today. How many candles to make from each new lot sets the release check that sits on top of this system.

Checking the system works before you need it

A traceability system is only real if it works on a random candle. Once a quarter, pick one finished candle from stock, read its batch number, and walk the chain backwards: batch sheet, lot codes, delivery record, retained sample. Time how long it takes. If any link is missing — a batch sheet that says "soy", a retained sample with no label, a candle with no batch number — fix that habit now rather than during a complaint. The drill needs no candles and no materials; it needs ten minutes.

If the drill keeps failing at the same link, the system is too complicated for your workshop — simplify the code, not the habit. When to manage wax as commercial inventory and the supplier-selection hub show where this fits as your volume grows.

Frequently asked questions