I’m Using the Same 7 cm Jar for Lavender, Vanilla, Coffee and Oud — Should I Expect One Wick Size to Work for Every Fragrance?

Why four oils rarely share one wick by default

A wick is sized for a system: wax, jar, fill height, load and oil together. Change the oil and you change part of the fuel the wick is drawing up. Many makers find that a wick set on a light oil runs differently with a dense or vanilla-rich one: a smaller flame, more carbon on the tip, a pool that is slower to reach the glass, or, with some oils, the opposite. These are tendencies reported widely, not rules, and they are exactly why "will one wick work?" has no answer until you burn it.

Your four oils also sit at four different points on that spectrum. Lavender is a light herbal. Dark Vanilla's page says "Vanillin present". Roasted Coffee has a dark, heavy heart and a vanilla-caramel base. Woody Oud has an oud and patchouli heart over woods, amber and musk. If they all passed on one wick, that would be a pleasant surprise; if two of them branch, that is normal.

And keep load constant across the screen. All four pages state "6-10%" for candles (Lavender as "Recommended fragrance load 6-10% for candles", the other three as "candles (6-10%)"), and CSI 464 states "Fragrance Load Up to 10%". 8% on total weight is inside every stated range, so the screen tests the oils, not the load. Whether each oil deserves its own load is the lavender-versus-vanilla load post; don't mix that question into this one.

The expectations sheet, from the product pages

An expectations sheet is not a result. It is a record of what you think will happen, based on what each page states, so that after the screen you can see where your intuition was right and where it wasn't. Build it only from page statements: stated load, family, notes, vanillin wording, cure. The "likely signal" column is a tendency, not a prediction for these particular oils; CSI has no wick data for any of them.

Three of the four pages state a 48–72 hour cure; Lavender's doesn't in the text we captured. Cure all eight candles to the same age, at least the longest stated and ideally about a week (common practice), so cure is not what separates them. The fuller version of this paper exercise, for twelve oils before any candle is poured, is the paper pre-screen post; for four oils, pouring the screen is almost as cheap as the paperwork.

The same-wick screen: eight candles

The house wick is whichever wick you already use in this jar, ideally one that has passed a full-life test with one of these oils. In the worked example it is Eco C2 in the Clear Glass Jar with Golden Lid (150 gram), a jar whose page gives a 7 cm outer rim, a 150 g fill and "Safe for hot pour up to 85°C" (a pouring figure, so pour CSI 464 at 80–85°C). If your house wick is C1, the logic is identical with the neighbours shifted.

Per candle, the oil alone is ₹64.80 for Lavender, ₹98.40 for Dark Vanilla, ₹55.20 for Roasted Coffee and ₹65.14 for Woody Oud at the 50 g price. Costs are worked examples and exclude labour, freight, packaging and GST. The 50 g bottle is the right size for every oil here: it covers the screen pair and a two-candle branch with 2 g to spare, and none of the 15 g bottles covers even the pair.

Reading each pair: pass, under, over, split

Some candles show both: a small flame and a heavy carbon cap. That combination is commonly reported with vanilla-rich oils, where carbon builds on a wick that is not burning hot enough to clear it. Classify it as U if the ring persists and as O if the pool is fine and only carbon and soot are the problem, and note the combination on the log. Whether a vanilla commonly needs a larger wick than a lavender in the same jar is the vanilla-versus-lavender post, which owns the offset bracket for exactly that case. How to score carbon build-up across many cycles is the mushrooming-after-several-cycles post.

Branching: only the failures get a bracket

In the worked example drawn above, Lavender passes, Dark Vanilla under-melts twice, Roasted Coffee splits and Woody Oud runs over twice. That is 13 candles in all: the 8-candle screen, two Cotton Braided candles for the vanilla, two C1 candles for the oud and a third house-wick candle for the coffee. A two-rung bracket for every oil from the start would be 16 candles, and a three-rung bracket 24. The best case for the screen is 8 candles (everything passes) and the worst is 16 (every oil branches), still below the three-rung bracket.

The branches need 690 g of wax: 294 g beyond what the screen left, hence one more 500 g bag. With the screen, the worked example consumes ₹3,217.58 of materials across 13 candles, excluding labour, freight, packaging and GST. Cotton Braided costs ₹2.56 more per candle than C2; the reason to be careful with it in a 7 cm jar is its page's "exceeding 8 cm" wording and the heat of the final third, not the price.

When every oil has a wick that has passed its full life, you have a one-jar range. If several oils ended up on the same wick, that group is the beginning of a house wick family (the wick-families post). If you are adding six more oils to reach ten, the adaptive grid in the ten-fragrance matrix post scales this method up without pouring sixty candles.

What to buy, and what to skip

Five cards: the four oils in the screen and the wicks it runs on, chosen on page statements, price and stock on 29 September 2026. CSI publishes no wick-performance or throw data, so nothing here is ranked on burn results; oils are in the order of the expectations sheet.

Frequently asked questions