How Do I Determine Whether Seasonal Wet-Spot Variation Comes from Raw Materials or Changes in My Workshop Environment?

The short answer: swap one side at a time

Seasonal wet-spot variation has two families of suspects, and they arrive together. The workshop changes: room temperature, the temperature of the glass when you pour, how fast batches cool, overnight lows, the AC and fans you switch on or off, monsoon humidity, even who is pouring when festival orders peak. The materials change too: by the time the season turns, you are usually on a newer bag of wax, a newer bottle of oil and perhaps a newer carton of jars. A candle that was clean in August and spotted in December could be telling you about either family, or both. Looking at the calendar cannot separate them.

What separates them is a swap test made on one day. Pour four small arms from the same jar lot, wick and pour temperature: today's materials in today's workshop (the control, which should reproduce the problem); good-season materials — your retained samples — in today's workshop; today's materials in recreated good-season conditions; and, optionally, both. If the arm with old materials comes out clean while the arm with recreated conditions spots, the materials changed. If it is the other way round, the workshop changed. That answers the question in one week of waiting, instead of a whole year of guessing.

Two things make this possible: retained samples of the good-season lots, and a record of the good-season conditions. If you have both, the test is cheap and decisive. If you have neither, the first job is free — write down everything that has changed since the good season (the audit below), and start keeping retained samples and room records today, so that next season the question can be answered. Room temperature as a recorded parameter sets up the condition record.

How each family can plausibly move wet spots

Wet spots are commonly described as places where wax has separated from the glass as it contracts while cooling and setting, leaving a thin air gap that looks dark through clear glass. The workshop family acts on that directly. A cooler room means cooler glass at the pour and faster cooling, both commonly cited contributors; a warm-day, cool-night room adds a temperature swing; monsoon conditions can change a room in ways a thermometer alone does not capture. Why colder temperatures can increase contraction deals with winter specifically.

The materials family acts more quietly. Natural waxes and fragrance oils are commonly described as varying somewhat from batch to batch, and a different lot can set slightly differently. CSI publishes no lot numbers, certificates of analysis or lot-to-lot consistency data for any wax or oil, and we make no claim that any of our products has changed. That is exactly why your own retained sample — a sealed portion of each lot, labelled with the order date — is the only way to put a previous lot beside a current one. Jars are materials too: a new carton, or a new supplier, can bring different glass; validating a new container covers that, and here you hold one jar lot constant across all four arms so the jar cannot confuse the answer.

Process drift is the third family, and seasons invite it. Festival volume brings bigger batches, longer fills from one melter, new helpers and shortcuts in jar cleaning. If your audit shows a process change, hold it constant in the swap test (everyone pours the same way on the day), and if the test points at neither materials nor conditions, test the process change on its own.

The swap test, step by step

Four arms of 3 jars, poured on one day from one jar lot, one wick lot and one pour routine. In the worked example the candle is the series default — 150 g in CSI's Clear 150 g jar at 8%, 12 g of oil and 138 g of wax — in Premium Coconut Soy Wax CSI 468 with Jasmine. CSI 468's product page states a pour of 58–60°C and the jar's page states hot pour up to 85°C; both are page statements, not tested limits. Each arm needs 434.7 g of wax and 37.8 g of oil with a 5% pour-loss working allowance, so a retained sample of 500 g of wax and 50 g of oil per lot is enough for one arm at this size. Three jars per arm is the labelled working minimum; if your retained samples are larger, add jars to every arm equally.

The scoring sheet and how to read it

Score each jar 0–4 on four marked sides (0–16 per jar) and count jars that fail your house line, such as any side at 2 or more. No industry figure exists for acceptable spotting; write your line before scoring and do not move it.

What seasonal variation costs, and what retained samples cost

The worked candle carries ₹235.28 of CSI materials — CSI 468 at its 5 kg rate (₹0.64 a gram), Jasmine at its 1 kg rate (₹3.92 a gram), an Eco Thin C1 at ₹5.90 as the example wick line and the jar at ₹94.40 — before labour, packaging, freight and GST. Here is what a seasonal swing in fail rate would mean on an example 1,000 candles a month; the rates are examples to show the arithmetic, not results.

The gap between the two example months is ₹21,175.38 of materials in extra failing jars — in one month. Against that, a retained-sample habit is cheap. Keeping back 500 g of wax and 50 g of oil from each lot means holding ₹318.50 of CSI 468 and ₹196.15 of Jasmine per lot at production rates. At an example 12 wax lots and 12 oil lots a year, that is ₹6,175.80 a year of materials kept on a shelf instead of poured — and most of it can be used once the lot after next has proved itself. Label each retained sample with the product, order date and pack, seal it, and store it cool and dry; CSI 468's page states a 60-month shelf life in cool, dry storage.

The priced test

With retained samples, the CSI part of the test is only the constants: one jar lot for all four arms, wicks and one cleaning product. Without retained samples, the weaker fallback is to compare your current open bag with a fresh sealed bag of the same wax and a fresh bottle of the same oil — that tests "is my current lot different from today's stock?", not "is it different from the good season's?", and you should read it that way.

The decision rule

Apply it at the 7-day checkpoint, using the outcome table above. Stop at the first true line.

Whatever the outcome, the record keeps paying. Start retained samples and condition logs now, and pilot batches in different seasons can check a new formula against every season before you lock it.

The CSI products in this test

Frequently asked questions