My New Soy Wax Batch Melts Differently From the Previous One Even Though the Product Name Is Identical — What Should I Compare Before Using It Commercially?

Same name, different melt: what that can mean

Soy and coconut-soy waxes are made from natural oils, and the exact mix of fatty acids shifts with the crop and the refining run. Manufacturers blend and hydrogenate to a target, but a target is a range, not a point. So a new lot of wax with an identical product name can start to soften a degree or two earlier, turn fully clear a little later, or thicken on cooling at a slightly different temperature. Most of those shifts are small enough that finished candles look and burn the same. Some are not.

"Melts differently" also covers things that have nothing to do with the wax. A different pan, a fuller melter, a colder starting bag, a new thermometer or a thermostat that drifts can all change what you see. Before comparing lots, make sure you are comparing only lots.

The question in the title is what to compare before using the lot commercially. The answer is a short melting-behaviour profile on the bench, old lot beside new, followed by a matched pour. If the profiles and the pours agree, the lot goes into production. If they do not, you have specific evidence to take to your supplier rather than a vague sense that something is off.

Build a simple melting profile for each lot

You do not need a laboratory. You need two identical vessels, one heat source that treats them equally, a thermometer you trust, a timer and a notebook. A water bath — two identical steel pitchers standing in the same pan of hot water — is the fairest home method, because both samples see the same temperature and neither can scorch.

If your wax has a published melt point, use it as a reference for the range, not as a lot specification. CSI's Premium Coconut Soy Wax CSI 468 page states a melt point of 50–53°C and a pour temperature of 58–60°C. A lot that clears and clouds inside that stated range is behaving as the product page describes, even if it sits at a different end of it from your last bag. CSI does not publish a melt point for every wax, nor melt-point tolerances per lot for any of them; where one is missing, ask on WhatsApp (+91 7397976926) and record what you are told.

What to compare, and what counts as a difference

Put the two profiles next to each other. The table below is a template with suggested starting-point tolerances — they are there to make a decision possible, not because any standard fixes them. Tighten or relax them once you have a few lots of history.

Two patterns deserve particular attention. A new lot that clears at a noticeably higher temperature forces you to hold the melt hotter for longer, which adds heat history and can warm the colour of light candles. A new lot that clouds earlier on cooling shortens your pour window, so jars poured late in a batch may set rough or pull away from the glass. Either may be completely manageable, but you want to know before the first production pour, not after it.

Worked example: a 10 kg coconut-soy lot

Say you run a coconut-soy line and buy CSI 468 by the 10 kg bag at ₹6,370.00, which is ₹6,370.00 ÷ 10 = ₹637.00 per kg. The new bag seems to go liquid later in your melter than the last one.

You profile 300 g of each lot in a water bath. The old lot is fully clear at 55°C and the new lot at 57°C. On cooling, the old lot first hazes at 49°C and the new one at 50°C. Both results sit comfortably around the page's stated 50–53°C melt point, and both differences are inside the suggested 3°C flags. Colour, clarity and odour match.

That is a lot behaving within its stated range. The goods-in step that remains is a matched pour at your normal 58–60°C pour temperature, one jar of each lot, compared the next day for surface, adhesion and colour. The whole profile uses 600 g of wax — 0.6 × ₹637.00 = ₹382.20 — and much of it can be re-melted into test candles afterwards. A full wick and burn revalidation would be the wrong tool here; the bench profile has already answered the question you had.

Now change one number. Suppose the new lot hazed at 54°C instead of 50°C on cooling. That is outside your suggested flag and close to your pour temperature, which means jars would begin setting almost as soon as they are filled. That lot should stay in quarantine until you have run a matched pour at two or three pour temperatures and spoken to the supplier.

From profile to production decision

Once the bench profile and the matched pour are done, the decision is usually clear.

Accept when the profiles sit within your flags and the matched pour looks the same. Conditional release when one parameter is at the edge — a slightly earlier cloud point, say — and the matched pour is acceptable: use it with a note to watch surface finish on the last jars of each batch, and keep jars from the first production run aside to review after cure. Quarantine when any parameter is outside your flag, or the liquid is darker, hazy or odd-smelling, until you have a matched burn result and a supplier answer. Reject when finished candles from the matched pour fail your appearance or burn standard.

Write the profile readings into the lot record along with the date received, product, invoice number and decision, and keep a sealed portion of the lot as next time's reference. After three or four deliveries you will know your supplier's normal spread in clear point and cloud point, and the next "it melts differently" will take ten minutes to confirm or dismiss. If a lot does fall outside it, raise it with whoever supplied it — including us — and keep the old and new samples until you have an answer.

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