How Do I Compare an Older Production Batch With a Newly Manufactured Batch Without Letting Personal Scent Familiarity Distort the Result?

The nose that knows your fragrance best is the least reliable judge

You want to know whether a Jasmine batch poured in May still matches the batch you poured this week. You are also the person who has weighed, poured, sniffed and sold this fragrance for a year. That familiarity feels like expertise, and for designing a fragrance it is. For comparing two batches it works against you in at least three ways. Your nose adapts to odours you meet all day, so a scent that fills your workshop can seem weaker to you than to a visitor. Your memory holds an idealised version of the fragrance, and every real candle is judged against it. And you know which jar is old, so you expect it to be weaker and tend to find what you expect.

None of this means your judgement is useless. It means the comparison has to be built so that your knowledge, your adaptation and your expectations cannot steer the result. The rest of this page is about building that structure: equalising the two candles, removing your knowledge of which is which, choosing assessors, and controlling the order and timing of sniffing.

Equalise everything except age

The older batch has usually lived somewhere different from the new one. It may have come from a warm warehouse shelf; the new batch may still be in the cooler finishing room. A warm candle gives off more cold throw than a cool one, so a temperature difference alone can make an old candle seem stronger or a new one seem weaker. Before any comparison, put both candles in the same room, lids on, for a suggested 24 hours so they settle to the same temperature.

Write the conditions on your record sheet: room, time, how long the candles settled, lid-off time and who coded the jars. If the comparison is ever questioned, the record shows that the only planned difference between the two candles was their age.

Choosing and briefing assessors

Ideally use three or more people. At least two should not work with this fragrance daily; family members, a friend, or a colleague from packing or accounts are fine. Brief everyone the same way, with a written prompt rather than a conversation, and do not mention which batch is newer or what you expect. Ask them to describe each coded jar in their own words first, then to rate strength on your usual scale, then to say whether the two differ and how. Collect answers on paper before anyone discusses them, because one confident voice can pull a whole group.

What useful notes look like

Strength ratings alone hide the most interesting changes. Ask for two or three words per jar on character: sweet, green, powdery, sharp, soapy, flat, fresh. Ageing often shows up first as a change of balance, with the bright opening receding and the base seeming heavier, while overall strength barely moves. If three assessors independently write that one jar is less fresh or more heavy, that agreement is worth more than a half-point gap on the strength scale.

Keep a short glossary of agreed words on the briefing sheet so people are not inventing vocabulary on the spot, but never list words that hint at the expected answer. A neutral list covering both fresher and heavier descriptions keeps the prompt fair.

Worked example: May Jasmine against October Jasmine

Two batches of the same Jasmine formula in CSI 468 at 8% of total weight: batch J-0512 and batch J-1004. The May batch has spent five months on a warehouse rack; the October batch has just finished curing. A helper labels the May jar K and the October jar R, notes the key in a sealed envelope, and places both in a quiet office overnight. Next morning, before any pouring starts, four assessors each receive both jars. Two smell K first, two smell R first.

Three of four describe both as soft white floral; three of four rate R one point stronger on a five-point scale; two of four describe K as slightly greener and less sweet. These are example results. Opened, the envelope shows K is the May batch. The reasonable reading is a modest, consistent drop in strength with a small change of character, not a different fragrance. Whether that passes depends on the tolerance in your written standard, set before the session.

A third, anchoring candle helps when results are borderline. Pour a fresh candle from your retained oil sample of the May lot, if you kept one, and add it to the session as a third coded jar. Its oil at the 1 kg Jasmine price (₹3,923.00 ÷ 1,000 = ₹3.923 per g) costs 16 g × ₹3.923 = ₹62.77, and the wax at the 10 kg CSI 468 price (₹6,370.00 ÷ 10,000 = ₹0.637 per g) costs 184 g × ₹0.637 = ₹117.21, before jar, wick and labour. If the fresh pour from the May lot matches R, the change in K is ageing; if it matches K, the two oil lots may differ, which is a separate question.

The session, step by step

Deciding, and what it means for buying

If the older batch passes, record the age it reached and keep shipping inside that evidence. If it fails, look at how long you actually hold this fragrance, and pour it closer to sale. CSI fragrance-oil pages publish no shelf life or storage data, so ask on WhatsApp (+91 7397976926) for the IFRA certificate, MSDS and any storage guidance for your Jasmine lot, in writing. And resist the temptation to fix a slow-moving fragrance by buying more of its oil at the cheaper 1 kg rate: if batches are already drifting on the shelf, more oil in the store room only adds another thing that can age.

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