Ultimate Guide to Candle Testing

Thoroughly testing your products is critical to make sure your products are safe, compliant with relevant laws, and also of amazing quality to keep your customers returning time after time.

Our ultimate guide will walk you through the why, what, and how—everything you need to know to make sure you produce amazing quality products that are, most importantly, safe to burn.

Prior to launching any product on the market, it must undergo thorough testing. This is crucial not only for producing visually appealing and pleasantly scented products but also to ensure your business remains safe and compliant with applicable laws. Many creators are unaware that an unsafe product could not only damage their reputation but also result in hefty fines and potential civil liability, with the possibility that insurance may not cover their claim.

Follow our best practice guide below to be reassured that you have got this under control.

Why do we test our candles?

What do we need to record?

Assessing the results

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Why do we test our candles?

We test our candles for two main reasons, to make sure our products are the best that they possibly can be, but also to remain compliant.

Customer Satisfaction

While this process is frustrating, and sometimes very costly, making sure your candles perform the best that they can will be the difference between customers returning time after time, and recommending your products to friends and family, or some very upsetting online reviews.

Burn Quality - Making sure that you have the correct wick size for your chosen wax, vessel and fragrance load will make sure that your candle burns slowly with an even melt pool. A wick of the wrong size can cause mushrooming of the wick, tunnelling, a huge flame and more. Read our Choosing your wick guide for more information.

Scent Throw - We all want our candles to smell beautifully both unlit and while burning. A burn test will establish how well your chosen wax and fragrance oil interact, it helps us ensure that we have the optimal level of fragrance oil for an amazing hot and cold throw without seeing any mushrooming or smoking of the candle.

Aesthetics - We want our products to look great, after all we need our customers to be interested enough in the product to pick it up and smell it. Testing will make sure that the candle does not have imperfections such as frosting or wet spots and make sure we have a nice smooth finish. After the burn we can check for any discolouration or black soot which will put customers off buying again.

Safety and Compliance

Once we have perfected our product and are comfortable that we have the optimal combination of ingredients to produce an amazing candle before we can sell (or even give away) our product we need to ensure that the product is safe to release to market.

Customer Safety - Candles involve open flames so they are inherently risky therefore safety has to be our top priority. There are a number of things that we can test for to reduce risk of an incident. As part of our testing we can make sure our vessels don't crack, our candles don't overheat and our flame size is safe.

Compliance - In the UK and Europe all products released to market must comply with GPSR (Global Product Safety Regulations). Under GPSR candles are legally labelled as hazardous products and therefore makers are legally bound to ensure they are safe to be sold. Having documented records of your testing will demonstrate that you have complied with requirements. Failure to comply can result in a "effective, proportionate and dissuasive" fine that can reach up to £100,000.

Liability - If a product causes physical injury or property damage your customer could look for financial compensation. No matter how hard we try unfortunately sometimes accidents do happen. Usually if a claim materialised this would be passed straight to our insurers to resolve. Our insurers will ask to see records of our testing at the outset, if this is not available, or insufficient they can deem our products to be non-compliant and refuse to cover any damages awarded.

What do we need to record?

We need to have some way of documenting our test results. We offer a range or solutions for all budgets to help you record your testing.

• Our candle testing Log Book

• A PDF printable of the test sheets

• A Live file (Google Sheets or Excel required) to track your testing

We need to ensure our results are documented, organised and readily available for inspection if required by our insurers, Trading Standards or The Health and Safety Executive. You do not have to invest in one of the formal testing solutions above however they do provide extra peace of mind.

A good testing log will include:

• Production Information - Include the name of uour candle and the date of production. If you track batch numbers for your products you could note the batch number that the tested candle was taken from.

• Candle Specification - Include all of the ingredients of your product including vessel, wax, wick, fragrance and any dyes or additives.

• Production Values - This is effectively your method and should note the ambient temperature, heat to, scent added and and poured at temperatures and any curing time.

• Pre-Burn Observations - We should make some observations about the aesthetics of the candle including wet spots, frosting, sink holes etc as well as assessing the cold throw. We should also take a product weight at this stage to assist later when assessing the burn time.

• Testing Rounds - This will obviously depend on the size of your candle but I typically choose to do 4 rounds of testing, during each round is a 4 hour burn. Before we start each round I would typically record the date, ambient temperature and the weight of the candle before burning. During each burn we are making various observations. We are looking at the diameter and depth of the melt pool, assessing the hot throw and observing fame height and any sooting or mushrooming. I also measure the temperature of the melt pool to ensure the product is not overheating. Once the test is finished I let the candle cool completely and take a post burn weight and also observe the container for any cracks or weaknesses. This is repeated up to 4 times depending on the burn time of your candle.

To perform the test we need:

• A good set of digital scales, I use the salter 1160 available here. This is a smooth scale that is wipe clean which is very useful for any spillages.

• A thermometer, I like the thermopro TP168 as the probe is steady when hooked over the side of the jar. It is available here.

• A heatproof mat, I like these large silicone mats available on amazon here. They are big enough to test a few candles at once while keeping them out.

• Somewhere to record your results, check out our solutions in our shop.

Assessing the Results

When assessing the results of our test I find it best practice to look at this from a Safety and Compliance and Customer Satisfaction point of view as discussed above. I always choose to assess safety first, as no matter how good your product looks or smells, if it is not safe it can not be sold. Once we have established our candle is safe we can start to look at it from an aesthetic point of view.

Safety and Compliance - When assessing how safe the candle is we are looking at the following:

• No cracks or weaknesses in the candle vessel.

• No excessive flame height (see Choosing your wick).

• Container temperature within range (Glass under 65°C)

• No excessive build up of carbon.

If any of these tests fail at any point of the process you should stop the test immediately and record that product as a fail.

Candle Aesthetics - When assessing our candle from an aesthetic point of view we are looking at the look and smell of the product. We will be looking for:

• No wet spots

• Free from frosting

• A nice smooth top free of sink holes.

• Strong hot and cold throw.

• A full melt pool with no tunnelling.

• Slow burning.

• No mushrooming or sooting

• No discolouration.

Unfortunately achieving all of the above is the "Holy Grail" of candle making, and sometimes we have to make some sacrifices, particularly when working with natural waxes. The key is to know your customer and know what level of imperfection they will accept, for example would they accept a small wet spot to achieve a strong hot throw with natural wax?

The testing phase can take a considerable amount of time and can be very costly. and is often where prospective candlemakers decide to give up on their idea of a fragrance business. I think at this stage you have to be pragmatic. The safety/compliance tests are non-negotiable, however don't give up on your dream while striving for perfection as it is often unachievable, after all I am sure we have all bought an expensive candle at some point and ended up with some small mushrooms on the wick or some wet spots!

Hopefully this summary has helped you understand the candle testing process and why it is one of the most important steps when preparing to launch your product. If you have any questions or wish to leave a comment we would love to hear from you below.