Burn Test
Custom Vessel Burn Testing
When clients supply their own vessels for candle production, a comprehensive burn test is required. This essential step ensures each candle is safe, performs optimally, and provides an excellent fragrance experience.
What We Test
Wick size and type compatibility
Melt pool development and timing
Flame height and stability
Mushrooming, soot, or smoke issues
Hot throw performance (fragrance diffusion while burning)
Vessel heat transfer and safety (glass stress, lid heat, surface temperature)
Estimated burn time per fill weight
What to Send Us
To run your burn test, we require a minimum of 3 to 6 vessels shipped to our production facility. Contact us for our shipping address before sending your vessels.
This allows us to test multiple wick configurations across separate burns for accurate, repeatable results. Vessels that are fragile, irregularly shaped, or lidded may require additional units.
Once testing is complete, one finished full-size candle sample will be produced in your vessel and shipped to you for approval before full production begins. Sample shipping costs are not included in the burn test fee.
Testing Fees
Initial Vessel: $99 (includes wick compatibility testing, burn performance, and safety assessment).
Additional Vessel Types (within the same order): $50 each.
Burn testing typically takes 7-14 days. We’ll provide you with a detailed report confirming your vessels’ suitability before proceeding with full production.
Burn test fees are invoiced separately and due before testing begins. They are not applied toward your production order total.
The Process
Contact us to confirm your vessel details and receive shipping instructions
Ship a minimum of 3 to 6 vessels to our Gardena, CA production facility
Burn testing begins upon receipt (7 to 14 business days)
You receive a detailed burn test report with our findings and production recommendations
A full-size approval sample is produced and shipped to you
Upon your approval, full production begins
Using Handmade or Ceramic Vessels?
Handmade ceramics are beautiful, but natural variation in size, wall thickness, and interior volume means no two pieces are exactly alike. This directly affects wick selection, fill weight, and burn performance.
For handmade or artisan ceramic vessels, we require a minimum of 6 units to account for size variation across the batch. We test across multiple pieces to identify a wick and pour spec that performs as consistently as possible, even when the vessels themselves are not perfectly uniform.
Please note: if variation between your vessels is significant, we may not be able to guarantee identical burn performance across every finished candle. We will flag this in your report before production begins, so you can make an informed decision about moving forward.
Using Your Own Fragrance Oil?
We welcome client-supplied fragrance oils, but there are requirements that must be met before we can move forward.
What We Require
A current Safety Data Sheet (SDS) from your fragrance supplier
An IFRA compliance certificate for candle usage levels
Flash point confirmation (170°F minimum)
Sufficient fragrance oil to cover testing and your full production run, including a 10% material buffer
We cannot begin testing or production without complete documentation. This protects you, our team, and the integrity of your finished product.
Fragrance Testing
Client-supplied fragrances behave differently than our house library oils. Load rate, throw, and wick compatibility all vary by formula, so a burn test may be required even if you are using a standard UCC vessel. We will confirm during onboarding. If testing is needed, standard burn test fees apply.
A Note on Performance
When fragrance is client-supplied, UCC cannot guarantee scent throw or make claims about fragrance quality. We optimize load rate and wick selection within safe, tested parameters, but fragrance output is tied directly to the oil itself. Performance-related concerns with the formula are the client's responsibility.
UCC reserves the right to adjust fragrance load rate based on safety and performance testing. All client-supplied fragrances are catalogued under UCC internal identifiers for production and documentation purposes.
Fragrance Testing Fee
Client-supplied fragrance oils are subject to a $99 testing fee per scent. This covers load-rate evaluation, wick compatibility, and burn-performance assessment. Testing begins once all required documentation has been received and approved.
Fragrance testing is invoiced separately from vessel burn test fees. Neither fee is credited toward your production order.
