How to Choose the Right Wick Size for Concrete Candle Jars — India 2026

The wick is the most underestimated component of a candle. Get the wax right, the fragrance right, and the jar right — and then use the wrong wick and your candle will either tunnel (burn a narrow hole down the centre, leaving thick wax walls), mushroom (produce excessive soot and an oversized flame), or drown (the flame will extinguish in its own wax pool).

For Indian candle makers using concrete gypsum jars specifically, wick selection has some unique considerations because of our climate, the specific fragrance oils used, and the jar dimensions common in the Indian market. This guide covers everything.

The Three Ways a Wrong Wick Ruins Your Candle

Tunnelling — When the Wick Is Too Small

If your wick is too small for the jar diameter, the melt pool will only extend a few centimetres from the wick. The wax around the edges never melts, creating a deep tunnel in the centre of the candle. A tunnelled candle wastes 30-50% of the wax, burns out early, and frustrates customers enough to leave a bad review.

Mushrooming and Excess Soot — When the Wick Is Too Large

Oversized wicks produce too large a flame. The wick tip develops a carbon mushroom shape during burning. Excess soot blackens the inside of the jar, produces unpleasant smoke, and deposits carbon residue in the room. This is especially problematic in Indian homes where rooms are smaller.

Drowning — Fragrance Load Too High for the Wick

In India, candle makers often add too much fragrance oil because they want a strong smell. But fragrance oil thins the wax and creates a larger liquid wax pool. A wick that performed well at 6% fragrance load may drown and extinguish in a wax pool at 12% fragrance load. The solution is not less fragrance — it is a slightly larger wick.

The Jar Diameter Wick Guide for Concrete Gypsum Jars in India

India-Specific Wick Considerations

Humidity Adjustment — Monsoon Months (June to September)

Cotton wicks absorb ambient moisture in high-humidity conditions. During India's monsoon months, a wick that burns perfectly in dry November may struggle to stay lit in July. In high-humidity months, go one wick size up from your standard choice. For example, if you normally use CD-14, use CD-16 during monsoon season.

Fragrance Oil Impact on Wick Size

Different fragrance oils have different viscosities. Heavier, oilier fragrances like oud, musk, and sandalwood thin the wax more than lighter fragrances like citrus or lemon. When using heavy Indian fragrance oils, always test one wick size larger than you would for a standard fragrance.

Indian Summer Temperatures

In Indian summers (April-June), ambient temperatures can reach 38-42 degrees Celsius. This softens your candle's wax before it is even lit. A soft wax pool forms faster in heat, meaning your wick needs to be marginally smaller to avoid drowning in summer months. Reduce wick size by one step (CD-16 to CD-14) for summer batches if you are producing in a hot climate area.

How to Test a Wick Properly — The 4-Hour Burn Test

Never assume a wick works based on theory. Always conduct a 4-hour burn test before committing to a wick size for production:

1.    Light the candle and burn for 1 hour. Check: is the melt pool reaching the edges of the jar? If not after 1 hour, the wick may be too small.

2.    Burn for 2 more hours (total 3 hours). Check: is the flame height stable at 1.5-2cm? Is the wick tip charring cleanly or developing a mushroom shape?

3.    Burn for 1 final hour (total 4 hours). Check: what is the depth of the melt pool? It should be between 1-1.5cm deep. Deeper = wick may be too large.

4.    Extinguish. Wait 24 hours. Inspect the jar surface. Good: smooth, even re-solidification. Bad: deep sinkholes or rough surface = wax temperature was too hot (wick too large).

Specific Wick Recommendations for Popular Karessa Concrete Jars

•       Ribbed Candle Jar (#1 — 63mm diameter): CD-14 for soy wax at 8% fragrance. CD-16 during monsoon or with heavy fragrance oils.

•       Glass-Shaped Concrete Jar (#2 — 55mm diameter): CD-12 to CD-14 for soy wax. Test both.

•       Heart-Shaped Jar (#3 — 70mm wide, irregular shape): CD-16. Heart shapes burn unevenly due to the indent — go slightly larger to ensure full melt pool.

•       Tealight Jars (#12, #13 — 38mm diameter): CD-8. Standard tealight wick. Pre-tabbed tealight wicks are the easiest solution.

•       Concrete Ribbed Urli Bowl (#8 — 90mm diameter): Double wick with 2x CD-14, placed one-third from each edge. Single wick will tunnel in wide bowls.

Browse all jar sizes and dimensions at karessacandles.com/collections/concrete-candle-jars.