I'm Switching From Soy Wax to Coconut-Soy Wax — Do I Need to Recalculate the Fill Weight for My Existing Candle Jars?

What the switch does to the gram figure

Start from what a fill weight is. You pour to a line. The space below that line is a fixed volume, set by the glass and your tape, not by what goes into it. The finished candle's weight is that volume multiplied by the weight per millilitre of the set wax-and-oil mix. Swap the wax and you swap only the second number. Nothing else in the multiplication moves.

So the honest question is how different the two waxes are per millilitre. We cannot tell you: neither the CSI 464 nor the CSI 468 page states a density, and we will not invent one. What we can do is show how much a plausible difference matters, using the standard jar from this series.

Worked example: how far a small density difference moves your candle

The series' standard worked-example jar is CSI's "200 ml" matte family (listed 8 cm high, 7 cm wide), treated as straight-sided with a 7 cm-deep inside. That gives about 28.6 ml per centimetre of height. With the common 0.86 to 0.9 rule of thumb for wax against water, each centimetre holds about 24.6 to 25.7 g of candle, and a 150 g candle stands roughly 5.8 to 6.1 cm tall. The full derivation is in the fill-weight hub.

Now suppose, purely for illustration, that CSI 468 weighs 2% more or less per millilitre than CSI 464. Two things can happen, depending on how you pour.

Three grams on 150 g, or a millimetre of height, is inside the variation you already see between two jars from the same pack. That is the real answer to "do I need to recalculate": the arithmetic stays the same, but the number should come from a weighing, not from the old spec sheet. If you want the density physics itself, why wax is lighter than water and why it shrinks as it sets, it is in the density explainer.

Where a bigger gram difference can come from

If your side-by-side pour shows more than a few grams of difference, look at the process before blaming the wax. The usual causes are a different surface (one wax sank and was topped up, the other set flat), a different load (the oil went in by eye), jar-to-jar variation (mass-produced glass varies, so compare two jars from the same pack), or pouring one wax hot and fluid and the other near its set point, which changes how it sits against the tape line. Fix those and re-weigh.

The side-by-side fill-weight check, step by step

This check answers exactly one question: does the same jar, filled to the same line at the same load, weigh the same in CSI 468 as in CSI 464? Run it on jars from your current stock so the glass is the glass you sell.

Pour temperature: the change that matters more

CSI 464's page states a pour temperature of 80–90°C. CSI 468's states 58–60°C and a melting point of 50–53°C. That gap reaches into three parts of your process.

1. The jar's stated heat figure

Only a few CSI jar listings state a number: the 150 g apothecary-style family, such as the Clear Glass Jar with Golden Lid (150 gram), and the Apothecary dome-lid jar say "Safe for hot-pour up to 85°C". In those jars, CSI 464 has to be poured at 80–85°C, the overlap of the two stated ranges; the lower limit governs. CSI 468's 58–60°C sits 25–27°C below that figure. For jars that state no number, including the White Matte 200 ml family ("withstand high heat"), neither temperature is covered by a stated figure, so a full burn-down test on your jar is still the only evidence. A lower pour temperature is not a safety certificate for any jar.

2. How far the wax cools, and how it sets

In an illustrative 30°C room, CSI 464 poured at 80–90°C cools through 50–60°C; CSI 468 poured at 58–60°C cools through 28–30°C. Waxes shrink as they cool, and many makers find that a wax poured cooler settles with a shallower dip and fewer sinkholes. That is a tendency, not a CSI measurement: we publish no shrinkage data for either wax. It is also a likely reason your set surface, and so your fill line, looks different after the switch. Wet spots, where set wax pulls away from the glass, are commonly linked to the temperature difference between wax and glass; a cooler pour into a room-temperature jar changes that difference, so look at the sides as well as the top.

3. The accuracy you need

A ten-degree window forgives a rough thermometer. A two-degree window does not. If you have been pouring CSI 464 "when the jug feels right", the switch is the moment to buy or check a thermometer. Pour too hot and you lose the benefit you switched for; pour too close to 50–53°C and the wax can start to set in the pitcher and pour unevenly against the tape line.

Wick, top-up and cure: the retests you cannot skip

The fill-weight check takes a day. The retests below take the week, and they are where a switch succeeds or fails. They apply even if your side-by-side jars weighed exactly the same.

Five CSI 468 candles cover all of it: jar B from the fill-weight check (with your current wick), plus four more split between your current wick and its neighbour. Burn each for a first session of about 3–4 hours and log the pool width every hour. A common rule of thumb is a full pool to the glass within that time and about 0.5–1 cm deep. If your current wick now gives a tall flame or soot, the smaller rung wins; if it still tunnels, you had a marginal wick in CSI 464 too. Why the same oil can also perform differently in a different soy-based wax is covered in our wax-and-fragrance guide.

Several CSI oil pages state a cure of 48 to 72 hours for soy wax candles before burn testing; many makers cure soy-based candles for longer before judging throw. Keep your usual cure and compare it with a later burn rather than changing two things at once. A full list of what to retest when the jar changes rather than the wax is in I'm Changing My Candle Jar to Reduce Costs — Which Parts of My Existing Formula Need to Be Retested Even If the Wax and Fragrance Remain Unchanged?.

Does the 13% ceiling change your recipe?

CSI 468's page states "Fragrance Load Up to 13%"; CSI 464's states "Up to 10%". Under the two-ceilings rule, the lower of the wax's stated maximum and the oil page's stated candle maximum governs. So the switch raises your ceiling only for oils whose own page goes above 10%. Across CSI's 102 oil listings, 48 state a candle load; of those, 42 top out at 10%, three at 9%, and three go higher: Japanese Cherry Blossom (6–13%), Cinnamon Vanilla (up to 13%) and Autumn (7–11%).

A ceiling is a maximum, not a target. Whatever the wax, we suggest testing 6%, 8% and 10% (Autumn's page starts at 7%) and choosing the lowest load that performs. Changing the load does not change the fill weight either: at 150 g, 8% is 12 g of oil and 138 g of wax, and 10% is 15 g and 135 g. The wax-per-jar arithmetic of a load change is in I Changed My Fragrance Load From 6% to 10% — Will That Change How Much Wax I Need to Put Into Each Jar?.

What to buy for the switch test

You already have the jars and the oil; this is what the test adds. Chosen on what the pages state, price and stock on 26 September 2026, not on burn data: CSI publishes no burn-test results for these products.

What the switch costs per candle and per order

Worked example at 10 kg prices for one 150 g candle at 8% (138 g of wax), excluding labour, freight, packaging and GST. The fill weight is assumed unchanged, which your side-by-side check will confirm or correct.

Switching from CSI 464 to CSI 468 adds ₹17.89 of wax cost to each 150 g candle and ₹1,944.00 to a 100-candle wax order. At 100 candles a month, that is ₹21,468.00 a year. Whether it is worth it depends on what the tests show and on your price, not on the fill weight. Two pricing details: CSI 468's 500 g and 1 kg both work out at ₹0.65 per gram and its 5 kg and 10 kg at ₹0.64, so the saving from buying big is a penny a gram. CSI 464's 500 g is ₹0.52 per gram and every larger size ₹0.51.

The five test candles use 690 g of CSI 468, worth ₹448.50 at the 1 kg price, and 60 g of your oil at 8%. The remaining wax covers pitcher residue, a top-up or two, and a re-pour if a wick fails. If you only want the fill-weight answer and will test wicks later, the 500 g (₹325.00) covers the side-by-side pair.

Switching before Diwali, 8 November 2026?

Diwali falls on 8 November 2026, 43 days after these prices were checked. A wax switch needs a test pour, a cure, burn tests at two wick sizes and a final-third burn before a production pour, and then the production batch needs its own cure. That fits in 43 days only if the test starts this week and nothing fails. Dispatch is from Pune; confirm delivery time on WhatsApp before you plan around it.

Our judgement: Route B is the safer choice for most makers. Your Diwali customers get the candle you have already proven, and the switch gets a full test cycle before Christmas on 25 December 2026, 90 days out.

Frequently asked questions