My Customer Says Their Candle Smells Different From a Previous Purchase — How Do I Determine Whether Ageing or a Raw-Material Lot Change Is Responsible?

Two suspects, and they can look identical

A repeat customer writes: the Lavender candle they bought in September does not smell like the one they bought in March. Nothing in the message tells you which way the difference runs, and nothing in it tells you why. Two explanations compete. Either one of the candles has aged, so the customer is comparing a tired candle with a fresh one, or the two candles were made from different oil lots that are not quite the same. Sometimes both are true at once.

You cannot settle this by sniffing harder. You settle it by arranging comparisons in which only one thing changes at a time. Make two candles that differ only in oil lot, and you learn about the lot. Compare two candles that differ only in age, and you learn about ageing. This page sets out that arrangement, using the retained candles and retained oil samples that your batch records should already hold.

Questions to ask before you pour anything

Ask the customer for the base labels of both candles if they still have them, or at least the newer one. Ask which one they are holding now, whether the older one has been burned, where each was kept, and in what way they differ: weaker, sharper, sweeter, greener, flatter. A customer comparing a new candle against a half-burned March candle that has sat open on a sunny shelf is describing a very different situation from one comparing two unopened jars.

Then open your own records. Look up both batch codes. Note the pour dates, the oil lot each batch used, whether the formula version changed, and the storage log for both batches. If the two batches used the same oil lot, the lot-change hypothesis is already off the table, and the investigation becomes a question of ageing, storage or perception. If they used different lots, you need the comparisons below.

The comparison grid

Assume batch A was poured in March from oil lot 1 and batch B in September from oil lot 2, both Lavender in CSI 464 at 8% of total weight. You hold a retained candle from each batch and a sealed retained sample of each oil lot. Pour two fresh candles on the same day, in the same wax, one from each retained oil sample, and cure them together. You now have four candles that can be compared in pairs.

Read the first two rows together. If the fresh pours from lot 1 and lot 2 match but retained batch A has drifted from its fresh twin, ageing explains the complaint. If the fresh pours differ and batch A still matches its fresh twin, the lot change explains it. If both rows show a difference, both causes are in play, and you will need to judge which is larger. One caution: the retained lot 1 oil has itself been stored for six months. Keep it sealed, cool and dark, and note its age on the record; a difference between the fresh pours is a difference between lots as they are today.

Worked example: the cost of the two fresh pours

The fresh pours do not need to be full-size candles. Using clear 70 g votive jars keeps the oil you consume from the retained samples small. At 8% of total weight, a 70 g candle holds 64.4 g of wax and 5.6 g of oil. Each votive jar costs ₹318.60 ÷ 10 = ₹31.86 from the 10-pack. With CSI 464 and Lavender at the larger-pack prices, one votive costs 64.4 g × ₹0.5074 = ₹32.68 in wax plus 5.6 g × ₹5.221 = ₹29.24 in oil, then ₹32.68 + ₹29.24 + ₹31.86 + ₹5.90 = ₹99.68 including an Eco C1 wick. The pair costs 2 × ₹99.68 = ₹199.36, excluding labour and GST.

Votives are fine for a cold-throw comparison and a short supervised burn. For a full hot-throw judgement in the customer's jar size, pour full-size candles instead; the logic of the grid stays the same. Smaller jars burn differently, so use them to compare the lots and the ages with each other, not to predict exactly how a full-size candle will perform.

When the grid finds nothing

Sometimes all four candles line up: the lots match, batch A held its character, batch B is as made. That is a real result, not a failed investigation. It points away from your materials and towards what happened after dispatch, or towards perception. A March candle that has been opened, burned a few times and left lidless on a warm shelf for six months is no longer the candle you shipped. Equally, a customer who has lived with a fragrance for months may notice the bright opening of a fresh jar more than they ever did before.

In that case, say so gently and specifically. Explain what you compared, that both batches still match your standard in your storage, and share simple care advice: keep the lid on between burns, store away from sunlight and heat, and burn long enough for a full melt pool.

Running the investigation

What to do with the answer

If ageing is the cause, the formula is the issue, not the supplier. Shorten the window you ship within, pour this fragrance closer to sale, and review how long batch A actually sat before dispatch. If the lot is the cause, send CSI the details on WhatsApp (+91 7397976926) with both lot numbers, and ask for the IFRA certificate, MSDS and any storage or shelf-life guidance for each lot, in writing; CSI product pages publish none. Treat the new lot as a fresh qualification before it goes into more production. Either way, reply to the customer honestly: explain that you compared retained candles from both batches, what you found, and what you have changed, without promising that future candles will never vary.

Where this page fits

CSI already has guides that cover parts of this question. This page answers one fragrance-ageing decision; these cover the neighbouring questions:

Three things to buy for this decision

Frequently asked questions