My 500 g Test Formula Works Perfectly but My 5 Kg Production Batch Behaves Differently Even Though I Multiplied Every Ingredient Exactly — Why?

Your ratios are right. That was never the problem.

If you calculated 8% on total weight, your 500 g test was 460 g wax plus 40 g oil and your 5 kg batch was 4.6 kg wax plus 400 g oil. Both are exactly 8%. On paper the two candles are identical, so when the 5 kg run behaves differently, with a changed surface, a different throw or different adhesion, the cause must lie in something the recipe does not record.

A recipe records masses and percentages. It does not record how long the wax took to heat, what temperature it really was when the oil went in, how long it waited, how many times you walked a pitcher to the jars, or how cool the last jar's wax was compared with the first. At 500 g all of that happens in a few minutes and almost by accident. At 5 kg it stretches out and starts to matter.

Consider that the test may have been the imprecise batch

This is the possibility most makers skip. Weighing errors are roughly fixed in grams, not in percent. If your scale reads to the nearest gram, and yours may or may not, check its display, then a one-gram slip on 40 g of oil is 2.5% of the oil. The same slip on 400 g of oil is 0.25%. The 5 kg batch is, proportionally, the more accurate of the two.

So if the 500 g test was a little heavy on oil, or a little light on wax because some stayed on the spoon, the candle you fell in love with may have been running slightly above 8%. The 5 kg batch, weighed more precisely by default, is then the true 8% candle, and it smells like it.

What changes shape rather than scaling

Heating and cooling

A 500 g jug reaches temperature fast and drops fast. Five kilograms takes noticeably longer both ways, because its mass stores more heat relative to the surface through which heat leaves. If your wax maker gives an addition window, such as the 80–90°C stated for Eco Soy CSI 400, the 500 g batch passes through that window quickly while the 5 kg batch lingers in it or above it. Where you add oil within, or outside, that window can differ between the two without you noticing.

Stirring reach

CSI states a 2-minute stir after adding fragrance to Eco Soy CSI 400. In a 500 g jug, two minutes of stirring moves the whole mass many times over. In a deep 5 kg pot, the same two minutes may leave the base or the corners under-stirred. Treat the stated time as the minimum and judge the end point by the whole batch looking uniform, with no streaks and nothing lying at the bottom when you scrape.

Pouring trips

A 500 g batch is often poured straight from the jug it was made in. A 5 kg batch is poured in trips. CSI's large steel pitcher holds 600 ml, and at a rough 0.9 g per ml for melted soy wax that is somewhere near 540 g if filled to the brim, which nobody pours safely. With a sensible working fill you are looking at roughly ten trips for 5 kg. Every trip is a small cooling event, and the wax left in the pot waits while you pour.

Reading the symptom back to the variable

"Behaves differently" can mean several things, and each points somewhere different. Use the symptom to narrow the search before you remake anything.

Tops or surfaces differ, mostly in later jars. This usually tracks pouring temperature drift across the trips. The first jars were poured from wax fresh off the heat; the last from wax that had waited. Compare the logged first and last pour temperatures.

Throw is weaker across every candle. Look at the addition temperature and the time the batch sat hot, and recheck the benchmark precision discussed above. A uniform change points to something that happened to the whole batch at once.

Throw varies from candle to candle. That is a distribution question: stirring reach, or a pause long enough for the batch to sit unstirred between trips.

Wax pulls away from the glass in some jars only. Jar temperature and the wax temperature at the moment of pouring both play a part, and at 5 kg the jars filled last often waited longest on a cool bench. Note which positions on the bench were affected.

Writing the symptom down in this form, with which jars and which trip, often solves the problem before any retest is poured.

A 5 kg routine to compare fairly

What to do with the comparison

Once both batches have been made to a controlled routine and cured for the same period, burn them side by side. If they now match, the original difference was process and your 5 kg routine is the production method. If the new 500 g tests also differ from your first test, the benchmark was the problem, and you should decide which version of the candle you actually want to sell.

If the 5 kg candles still differ and all the logged temperatures match, look at materials. A 5 kg pack of CSI 400 at ₹1,996.00 may come from a different production run than the 1 kg pack at ₹399.00 you tested from; making a fresh 500 g test from the new pack answers that directly. Only after all of this is it worth thinking about equipment.

Keep one principle from this exercise for every future step up in size: whenever the batch grows, ask what the recipe does not write down. At 5 kg it was time, temperature and trips. At 20 kg the same list returns with larger numbers, and the makers who scale smoothly are the ones who began recording those variables while the batches were still small enough to repeat cheaply.

Where this page fits

CSI already has guides that cover parts of this question. This page takes the production-floor angle; these go deeper on the rest:

Three things to buy for this job

Frequently asked questions