I Want to Make 100 × 150 g Coffee Candles — How Many Kilograms of Wax, Coffee Fragrance Oil, Wicks and Jars Should I Purchase After Adding a Production Buffer?

The kilograms, after the buffer

One hundred 150 g candles are 15 kg of finished candle. At an 8% load that is 1,200 g of coffee oil and 13,800 g of wax — 12 g and 138 g per candle. The buffer on top is built from four labelled working assumptions: three test candles to settle the fill line and the wick in the jar, a 4% reject allowance on wax, oil, wicks and stickers, 5% pour loss on wax and oil only, and 3% breakage on the glass jars only. Here is what that adds up to, line by line, in kilograms and pieces.

Notice that the buffer is not the same size on every line, and should not be. Wax and oil carry tests, rejects and pour loss, so they grow by 12.7%. Wicks and stickers carry tests and rejects but not pour loss — a wick does not stay behind in the jug — so they grow by 8%. Jars carry tests and breakage but not rejects, because a rejected candle is melted out and its jar cleaned and reused; they grow by 7%. That gives ₹163.53 of CSI materials per saleable candle, against ₹143.69 for one candle's own BOM before any buffer.

Why "add 10% to everything" is the wrong buffer

The most common production buffer is a flat 10% on every line. It is easy, and it is wrong in two different directions at once. It is too much on the lines that do not lose material in the jug — jars and wicks — and it can still be too little on wax and oil when the run includes test candles and a reject rate above a couple of per cent. Worse, it is often applied to the wrong base: 10% on top of "100 × 150 g of wax" treats the finished weight as if it were all wax.

On this order a flat 10% on the net BOM lands within ₹136.78 of the named stack in rupees (₹16,216.64 against ₹16,353.42) — but it gets there by being wrong twice. It is short on coffee oil: 1,320.0 g against the 1,351.9 g that three test candles, 4% rejects and 5% pour loss actually consume, a gap of 31.9 g, or about 2.7 candles' worth of oil. Even after pack rounding the flat order brings in 1,330 g of oil — still 21.9 g short, so the last candle or two of the run would have no coffee to go in them. And it buys more wicks than the run uses, because a wick is never lost in the jug. The 10%-on-finished-weight version is worse again: it over-orders 953 g of wax because it forgot that 8% of every candle is oil. The named stack is the only version where you can say what each extra gram is for. The 105-or-110-pieces post runs the same comparison for an order measured in pieces.

Building the buffer step by step

The 200 ml Salsa jar and a 150 g candle

The 200 ml Salsa Glass Jar is the CSI jar this order is built around, and it is a reasonable candidate for a 150 g candle — but its fill weight is not published, so treat that as a test result you have not yet got. The jar is sold by its brim volume, 200 ml. Solid soy wax is lighter than water; at a labelled approximate 0.86–0.90 g per ml, 200 ml of wax weighs about 172 g–180 g filled right to the brim. A 150 g candle would leave roughly 22 g–30 g of that brim capacity unused, which is the kind of gap below the rim most makers want. That arithmetic suggests the fit; only a weighed test pour confirms it.

The jar comes with a golden lug cap, which removes one non-CSI line (lids) from the order. Small packs of five cost ₹40.12 a jar against ₹29.50 in packs of 50 or 100, so the cheapest way to 107 jars is one 100-pack plus two 5-packs — and buy one of those 5-packs first, for the test pour. The 100 g wedding-favour post uses the smaller Yankee 130 ml jar with the same brim arithmetic.

Natural Soy Pearl at 8%: what is and is not published

This order uses Natural Soy Pearl Wax because it is the cheapest container soy wax CSI lists and the only one with a real bulk price break: ₹450.00 a kilo at 1 kg, ₹424.80 a kilo at 5, 10 and 50 kg — 5.6% less. Buying the 16 kg as 1 × 10 kg + 1 × 5 kg + 1 × 1 kg costs ₹6,822.00; the same weight in 1 kg bags would cost ₹7,200.00. What CSI's page does not publish for Soy Pearl is a fragrance ceiling, melt point, pour temperature or shelf life. So the 8% on this page is a labelled starting point for testing, chosen from the general 6–10% range, not a specification — check the product page or ask CSI on WhatsApp for the wax maker's stated maximum before you plan around a higher load.

The priced order, in two stages

On this order the deciding material is the jar: if the Salsa jar does not hold 150 g to your fill line, the jar choice and possibly the candle weight change. Wax and coffee oil are needed whatever happens, so they can be bought first. The jar and wick production quantities wait for three test candles.

The two-stage total is the same ₹16,353.42 as the one-shot order, because the test packs are counted inside the final quantities: the five test jars are part of the 110, and the first 20 wicks are part of the 110. Nothing is bought twice. Roasted Coffee is bought as 1 × 1 kg + 3 × 100 g + 1 × 50 g + 1 × 15 g: its per-gram price is ₹6.21 at 15 g, ₹4.60 at 50 g, ₹3.90 at 100 g, ₹3.78 at 500 g and ₹3.74 at 1 kg, so the kilo bottle carries the bulk and the small bottles close the gap more cheaply than a second 500 g would. The minimum-leftover post shows the trade-off when you would rather have less oil left over than spend the least.

The CSI products on this list

Related questions in this cluster

The method here is the same as the 100-candle Lavender hub; what changes is the candle weight, the jar and which material the test decides. If you are sizing test candles rather than a production buffer, the burn-test budget post covers that. If your coffee candle is one of several fragrances in the run, 25 each of four fragrances splits the wax across them. Your first 100 candles separates bulk from small-quantity purchases, and the complete 100-candle plan adds dye and testing materials to the same list.

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