My New Lavender Fragrance Oil Is Slightly More Yellow Than the Previous Batch — What Should I Test Before Using It in Hundreds of Candles?

What a yellower lavender can and cannot tell you

A lavender candle in ivory soy is one of the plainest products you can sell, and that plainness is exactly why a change in oil colour worries you. Nobody expects a fresh, herbal scent to come in a candle that has turned cream or straw-coloured on the shelf. So when the new bottle pours a little more yellow than the last one, the useful question is not "is it the same?" but "will the difference show up anywhere a customer can see or smell it?"

Start with what is known. CSI's Lavender product page describes a single-note lavender with a fresh lavender top, a herbal green middle and a soft musk base, rates it "Strong" (the page's own rating, not a measured figure), and states a candle load of 6–10%. The page does not publish a flashpoint, a vanillin figure or any colour specification. That gap matters here: you cannot look up whether this oil is likely to tint wax, so you have to find out in your own wax.

A yellower tint in a lavender lot has a handful of plausible causes. Natural lavender-type materials vary between harvests and distillations. Some blend components deepen slowly with light and air, so an older lot or a warm-stored bottle can look richer. The musk or soft base materials may carry slight colour. And your previous bottle may have been paler than typical, which would make an ordinary lot look darker by contrast. Any of these can leave the scent unchanged. One or two of them can change it.

Three tests before the lot goes near a production run

Work through these in order. Each one is cheap, and each one either clears the lot or tells you exactly what the next test needs to answer.

1. Bottle comparison against your retained lavender

Pour a little of the retained previous lot and of the new lot into two identical clear vials to the same height and view them on white card in daylight. Photograph them. If you have no retained oil left, write that down honestly in your log — it limits how confident any later conclusion can be.

2. Odour on blotter strips

Lavender's top notes are the part customers notice first, and they are also the part most likely to have faded if a lot has aged or been stored warm. Dip labelled strips from both lots and compare them fresh, again after roughly 20 minutes when the herbal middle opens, and after an hour when only the musky base remains. If the new lot opens flatter, sharper or more medicinal than the retained one, colour is no longer your main concern.

3. A cured white-wax colour panel

This is the test that answers the commercial question. Make three small candles in your lightest wax on the same day: one with the retained lot, one with the new lot, one unscented control. Same jar type, same wax, same load, same pour temperature, same room. Then compare them in the same light at intervals — a suggested starting point is day 3, day 7 and day 14 — and leave one set on a bright windowsill and a matching set in a drawer if you can spare the materials, because light accelerates any yellowing.

Worked example: 300 lavender candles at 8%

Suppose your next run is 300 candles of 200 g at 8% load. Each candle needs 16 g of oil and 184 g of wax, so the run needs 300 × 16 g = 4,800 g of lavender. Buying five 1 kg bottles at ₹5,221.00 each comes to 5 × ₹5,221.00 = ₹26,105.00 of oil, and the oil in each finished candle costs 16 ÷ 1,000 × ₹5,221.00 = ₹83.54.

Now the test panel. For the three comparison candles you use 150 g clear apothecary jars, so at 8% each scented test candle takes 12 g of oil and 138 g of wax, and the unscented control takes 150 g of wax.

The panel costs a small fraction of the oil alone, before you count wax, jars, labels, packing and your hours for 300 candles. The larger point is not the ratio but the timing: the panel is only worth anything if it is finished before the production pour.

While the panel cures, you do not have to stop work. You can keep producing lavender with retained old-lot oil if any remains, or use the new lot for products where a slight yellow would not be seen, such as amber or tinted jars, and record that restriction.

Reading the panel and making the call

Two warnings about interpretation. First, if both scented candles yellow compared with the control, the issue is the lavender formula in your wax, not this lot — and that is something to discuss with the supplier and to plan packaging around, not a reason to reject this particular delivery. Second, a single panel is one observation. If the result is borderline, repeat it rather than argue with it.

And be honest about blending. It is tempting to stretch a nervous lot by mixing it half-and-half with your remaining good oil. If the new lot has passed, blending is harmless. If it has not, blending simply spreads an unexplained difference across more candles and makes a future complaint impossible to trace.

What to write down and ask

Your goods-in record for this lot should hold the product and size, your invoice number and receiving date, the vial photo, the strip notes at each interval, the panel photos by day, the decision and any restriction. CSI product pages do not publish lot numbers, so unless your label shows one, the invoice and date are your traceable reference; write them on each bottle.

Then ask the question you cannot answer yourself. Message CSI on WhatsApp +91 7397976926 with the vial photo and ask whether anything about the lavender has changed, and request the MSDS if you do not already hold one for this oil. Record the reply beside your own results. If your panel and the supplier's answer point in different directions, trust the panel for your product — it is the only test run in your wax, your jars and your light.

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