My New Fragrance Oil Creates Sweating in Soy Wax Even Though the Previous Batch Was Stable at the Same Percentage — What Should I Investigate?

First, is it really the same percentage?

Sweating — beads or a greasy film of fragrance oil on the candle surface — happens when the wax cannot keep all of the oil bound as it sets and ages. The same percentage worked with the old batch, and the new batch sweats. It feels like an open-and-shut case against the oil. It might be. But the words "same percentage" hide more room for error than most makers expect, and they are the first thing to check.

There are two different ways to express a fragrance load, and mixing them up quietly changes the amount of oil in the candle. CSI oil product pages phrase loads as a percentage of wax weight. This blog series calculates load as a percentage of total candle weight. The same number means a different amount of oil depending on which you use.

If one batch was made by someone working on total weight and the next by someone working on wax weight, or if your spreadsheet changed, the oil content moved even though everyone would swear the percentage was the same. Check the actual grams on your last two batch sheets before anything else. Then check the scale itself with a known weight — a sealed product of stated weight works — because a drifting scale doses more oil without anyone noticing.

Were you already running at the ceiling?

The second quiet factor is headroom. CSI's Luxury Soy Wax CSI 464 page states a fragrance load of up to 10%. If your candle sits right at that ceiling, the old oil batch may have been stable with no margin at all. A new batch that is only slightly less compatible with the wax — a little more of a material that binds poorly, for example — then tips the candle over the edge, even though the same batch would be fine a point or two lower.

Look at the table above again. A recipe at 10% of total candle weight is 11.11% of wax weight. If the wax's stated limit is read as a percentage of wax weight, that recipe is already past it. That does not prove your wax is overloaded — ask the supplier which basis the stated limit uses — but it is exactly the kind of detail that makes one batch sweat when the previous one just about held.

The investigation: every suspect, one check each

Work down the list. The first five checks cost nothing but time with your batch records and a thermometer. Only the last one needs new candles, and by the time you reach it, you will know that everything else was held constant.

The season deserves its own mention. Warmth softens soy wax and makes it easier for oil to migrate to the surface, so a batch that arrived as the weather turned hot can look guilty for a change the calendar made. If the old-batch candles are still sitting in the same room and have started to sweat too, the problem is storage, not the new oil.

Worked example: a load ladder with Zesty Lemon

The best test at this stage does two jobs at once: it compares old and new oil batches, and it shows how much headroom each one has. Make a small load ladder in the same wax bag, poured on the same day with the same jar, addition temperature and stirring.

Say your candle is Zesty Lemon in CSI 464 at 10% of total weight. CSI's Zesty Lemon page states up to 10% in soy and suggests starting at 8% and assessing after a 72-hour cure — so your recipe sits at the very top of that stated range.

Check the surfaces at the page's 72-hour mark and then again at later points — a suggested starting point is day 7 and day 14 — by pressing a clean tissue lightly on each surface and holding it up to the light. Photograph the tissues in a row.

Now read it. If candle 1 is dry and candle 2 sweats, the new batch is less stable in this wax than the old one at the same load: quarantine it and ask the supplier. If candles 1 and 2 both sweat, the batch is not your problem — something common to both is, most likely the wax bag or the warmer season. If candle 2 sweats but candles 3 and 4 are dry, the new batch is usable at a lower load, but that is a new formula and needs its own throw and burn check.

Notice the money in that last row. Dropping from 10% to 8% cuts the oil in each candle from ₹68.00 to ₹54.40, a saving of ₹13.60 per candle. If the lower load throws well enough, the sweating batch may have done you a favour by revealing an over-loaded recipe.

Record, ask, and decide

Whatever the ladder shows, write it down against the oil's invoice number and date received — CSI product pages do not publish lot numbers — along with the grams on the batch sheets, the room temperature and the tissue photos. Keep a small sealed retained sample of the new batch.

If the oil batch is the cause, send the supplier your ladder results and ask two things: whether anything in the formula has changed, and on what basis — total or wax weight — the stated load limit is given. For CSI oils, ask on WhatsApp +91 7397976926; MSDS and IFRA documents can be requested there too. Until the answer arrives, the batch stays in quarantine for this product. Do not blend it into your remaining old oil to spread the risk thinner; a partly sweating candle is still a sweating candle, and you will no longer know which oil made it.

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