How Much Raw Material Should I Retain From Each Batch for Future Comparison Without Creating Excessive Inventory Waste?

Size each retain by the test you would actually run

Most makers either keep nothing or keep far too much. The second habit is almost as unhelpful as the first: shelves fill with half-kilo bags of old wax that nobody labels, nobody uses and nobody throws away. The way out is to work backwards from the investigation. Ask what you would pour or sniff if a new lot looked different or a customer complained, and retain enough for that, with a little spare for a repeat.

For wax, the natural comparison is one test candle poured from the old lot beside one from the new lot. For fragrance oil, it is a blind smell-strip check plus one comparison candle. For wicks, it is one burn-to-end candle and a spare. For dye, it is one reference chip. Once you define the test, the quantity follows from arithmetic rather than guesswork.

The arithmetic for wax and oil

This series calculates fragrance load as a percentage of the total candle weight. A 70 g clear glass votive at 8% needs 70 × 0.92 = 64.4 g of wax and 70 × 0.08 = 5.6 g of oil. A 200 g jar at 8% needs 184 g of wax and 16 g of oil. So a 100 g wax retain covers one votive-sized comparison with 35.6 g to spare, while a comparison in your full 200 g production jar needs at least 184 g. Choose the retain to match the vessel you would test in.

These figures are deliberately small. If your own comparisons regularly need more, because you always test in two jar sizes or run repeat burns, raise them. If you never test in anything bigger than a clamshell wax melt, you can reduce them. The table is a place to start, not a standard.

Worked example: a year of retains for a growing maker

Take a maker who buys wax monthly and runs a small range of eight fragrances. Over a year that is 12 wax lots of CSI 468 coconut soy, 24 oil deliveries (eight oils, each reordered three times) and six deliveries of thick Eco wicks. Price each retain from the pack actually bought, using the 10 kg wax pack and a 1 kg oil such as Bergamot Amber for the illustration.

Physically, that is 1.2 kg of wax, 360 g of oil in 24 small bottles and 30 wicks. It fits in two shoebox-sized storage boxes on one shelf, which is the real test of whether a retention plan is sustainable in a home studio.

Now compare an over-cautious plan that keeps 500 g of wax and 50 g of oil per lot. The wax line becomes 12 × 0.5 kg × ₹637.00 = ₹3,822.00, and the oil line becomes 24 × 50 g × ₹5.437 = ₹6,524.40. That is ₹10,346.40 before wicks, locked on a shelf, for comparisons that need a small fraction of it. Worse, large retains tempt people to dip into them for production when stock runs low, which destroys their value as references.

Keeping the space under control

Space problems come from lack of a system rather than lack of room. Three habits keep the retain shelf to a fixed footprint.

A disposal rule you can apply without thinking

A retain has done its job once no complaint about candles from that lot can reasonably arrive. A practical rule is: dispose of a retain when the last candle made from that lot has been with customers for longer than your complaint window, plus a margin. If your complaint window is six months, a margin of another six months gives a starting rule of twelve months after the last sale from that lot. Validate that against how late your own complaints actually arrive, and adjust.

What to do with retired material matters too. Retired wax and oil should not go back into production stock, because that mixes an old lot into a new one without a record. Use them for practice pours, wick trials in scrap jars or wax melt screening in empty clamshells, clearly marked as not for sale. Retired wicks can be used for trial candles that you do not sell. Dye reference chips can be kept longer than the dye itself, because a chip is tiny and useful as a colour history.

Handled this way, retention costs a few thousand rupees a year and one shelf. That is a modest price for being able to answer a supplier, a customer or yourself with a side-by-side result rather than a memory. If our own wax or oil is the lot on the shelf, the same rule applies: the retain is there to find the truth, not to protect the supplier.

When to retain more than the table suggests

Raise the quantity for a lot you plan to use over many months, because you may need several comparisons during its life. Raise it for materials behind a bestseller, where a scent or colour complaint would affect many customers at once. And raise it when a lot arrived with a noted deviation that you accepted conditionally, so that you can re-test if the deviation turns out to matter. In each case, write the reason next to the log entry so the larger retain does not look like an accident later.

Where this page fits

CSI already has guides that cover parts of this question. This page covers the goods-in check for the question above; these go deeper on the rest:

Three things to buy for this job

Frequently asked questions