My 1 Kg Test Formula Is Approved — What Intermediate Batch Size Should I Make Before Jumping Directly to 25 Kg Commercial Production?

What an intermediate batch is actually for

An approved 1 kg formula tells you that a particular wax, oil, wick and jar work together at a particular load. It says almost nothing about what happens when the same recipe sits hot in a deep melter for far longer than a small pan ever held it, or when one person has to pour sixty candles from pitchers while the wax in the vessel slowly cools. Those are the things that go wrong at 25 kg, and none of them show up in a kitchen-scale batch.

So the intermediate batch should not be chosen by doubling or by picking a tidy number. Choose it by asking one question: what is the smallest batch that makes my commercial equipment, handling and timing behave as they will at 25 kg? For most makers the honest answer is one full, weighed fill of the melter they intend to use. That single load exercises the heat-up time, the point at which you add oil, the mixing you can realistically achieve by hand in a deep vessel, and the length of the pour.

A batch smaller than a full fill leaves a shallow pool in a large tank, which heats and cools differently from a full one. A batch larger than one fill means combining melts, which is a new variable in itself. One real fill sits in the useful middle.

Sizing the batch to a real fill, with the arithmetic

Start by weighing what your melter really holds. The CSI Electric Wax Melter page states it melts 9.5 litres of wax at a time. At roughly 0.9 g per ml for melted soy wax, that is approximately 8.5 kg of liquid wax, even though the variant is sold as the 10 kg capacity. Weigh one real fill of unscented wax to the level you would comfortably work at, and write that figure on the machine. It becomes the basis of every batch sheet that follows.

Suppose the weighed working fill comes to 8.5 kg of scented wax, and your approved formula is CSI 464 with Bergamot Amber at 8% of total candle weight. The intermediate batch is then:

Now cost it honestly. CSI 464 is ₹5,074.00 per 10 kg, which is ₹507.40 per kg at every pack. 7.82 kg × ₹507.40 = ₹3,967.87 of wax. Bergamot Amber is ₹5,437.00 per kg, so 680 g is 0.68 × ₹5,437.00 = ₹3,697.16 of oil. The intermediate batch puts about ₹7,665.03 of wax and oil at risk, before jars, wicks and labour.

The full 25 kg batch at the same load is 23 kg of wax and 2 kg of oil: 23 × ₹507.40 = ₹11,670.20 plus 2 × ₹5,437.00 = ₹10,874.00, a total of ₹22,544.20. The intermediate step costs roughly a third of that and tests the same process risks.

Run the intermediate batch exactly as you will run 25 kg

The batch only earns its cost if it copies the commercial routine. Use the same person, or the same crew, who will pour the big batch. Use the same pitchers, the same jars from the same carton, the same wicks, and the same cooling area. If you plan to add oil when the wax falls to a certain reading, use a separate thermometer rather than the melter display, because the product page states a ±10°C deviation on that display.

Keep oil addition below the oil's published flashpoint and well away from the melter's maximum setting. A full tank of hot wax is a serious burn risk, so wear heat-resistant gloves, keep the floor clear around the pouring station, and check that the socket and wiring are rated for a large melter running for a long period.

How to judge the intermediate batch before going to 25 kg

On the same day you pour the intermediate batch, make a fresh 1 kg control from the same wax and oil lots, using your original method. That way both sets reach the same cure age together. The product pages state a minimum of 48–72 hours for soy before burn testing; as a suggested starting point, compare again at day 7 and day 14, because some oils keep developing.

Burn a beginning, a middle and an end candle next to a control candle, in the same room, at the same time, with doors and fans set the same way. Judge throw blind if a second person can label the jars for you. Look at melt pool width and depth at matching hours, flame height, soot and the tops before lighting. Never leave a burning test unattended, and put out any test that smokes heavily or flares.

Three outcomes are possible. If all positions match the control, the process holds at this size and you can plan 25 kg. If all positions are weaker or different, something in the melter routine changed the product, and you diagnose here. If the beginning and end differ from each other, you have a distribution or temperature drift problem that a 25 kg batch would make worse, not better.

Moving from one fill to 25 kg

At 8.5 kg per working fill, 25 kg of scented wax needs three fills. Before the first commercial run, decide whether each fill is scented and poured as its own sub-batch, or whether fills are combined. Scenting each fill separately, with its own weighed oil and its own record, keeps every sub-batch the same size as the one you validated. Combining fills is a new process step and deserves its own trial.

Treat the first 25 kg run as a production batch under watch rather than a finished success. Keep beginning, middle and end retains from each fill, reconcile the yield — 125 candles of 200 g before losses — and hold dispatch until those retains match the control at the same cure age. If anything was learned during the intermediate batch, such as the mixing time needed to clear oil streaks at full depth, write it into the batch sheet now so it is repeated, not remembered.

If you need wax in quantities beyond the 10 kg pack, CSI quotes larger quantities on WhatsApp (+91 7397976926). Buy the commercial quantity after the intermediate batch has passed, not before, so that a process problem does not leave you holding stock bought for a run you cannot yet make.

Where this page fits

CSI already has guides that cover parts of this question. This page covers the failure investigation for the question above; these go deeper on the rest:

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