How Much Fragrance Oil Do You Need?
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Fragrance oil powers the main feature of scented candles: fragrance (duh!).
What’s the point of having a candle, otherwise?
There was a time in human history where candles were used for light instead of home decor, if you don’t count the insane Roman gift parties, that is. Some of these did have a smell, but it was the scent of animal fat (tallow) instead of a Mother’s Day garden.
Enter: the age of scented candles.
Most candle makers add fragrance oils to their wax blends. It’s pretty much a required skill for the job, but how much fragrance oil do you add? For some, the success of the candle relies on having a prominent smell – fragrance is the most important part of the process.
This article covers a simple and basic way to calculate how much fragrance oil to add to your (obviously amazing) candle blend. This assumes you’ve already calculated how much wax per candle you need.
Let’s get started!
Measure Fragrance Oil by Weight, Not Volume
Candle fragrances are available in huge variety.
CandleScience lists over 150 different flavors on their site – everything from Whiskey to Lilac. The ingredients list is different for all of them, too. Most have carrier oils, essential oils, and the most important ingredient of all: trade secrets.
Physical properties, like color, density, and flash point, all vary from one fragrance to another.
If candle makers had to keep up with all the unique characteristics of each fragrance, it would be a nightmare!
Fortunately, you only have to care about one property: weight.
(okay, weight isn’t really a “property”, but you understand…)
The “maximum fragrance” specified by wax manufacturers is based on weight, not volume.
Fragrances have such a variety in density it can be more work than it’s worth to narrow down a volumetric concentration specification that would actually be useful by your common chandler (who has time to waste doing chemistry experiments all day anyways?).
Weight is simply easier, all things considered.
That being said, keep the following in mind:
- Wax is measured by weight (and harder to measure by volume in a solid state anyways)
- Wax specifications for fragrance are typically based on weight
If you’re interested in a fill-in-the-blanks style worksheet you can print off (also known as a printable), you can download a free PDF here!
Basic Formula
Everything starts with a percentage.
The maximum fragrance load entirely depends on the wax. It is usually safe to assume 5% – 6% if it’s not listed, or you can’t find it.
The fragrance oil weight to add to your wax is pretty much just the chosen fragrance load (the percentage) multiplied by the weight of wax.
Let’s break it into easier steps.
Also make sure to pick up a scale before starting!
1 Measure Wax Needed for Candles
First, measure the wax you’ll need for all candles being poured in this batch. Make sure you know the weight in ounces or grams (but not fluid ounces – that’s for volumes).
2 Determine Desired Fragrance Load
Just because a wax can hold a lot of fragrance doesn’t always mean it should hold a lot of fragrance.
A lot of factors influence the hot throw of a candle – sometimes maxing out the fragrance actually makes the candle smell like burning fuel instead of a delicious bakery.
This specification is usually available on the wax supplier’s website if you are working with “market wax” (AKA, the most popular waxes for candle making available in the marketplace).
If you can’t find it, try to stay in the 5% to 6% range. As an example, paraffin wax IGI 4627, considered one of the best container waxes on the market, lists a maximum fragrance of 12%.(which happens to be very high).
Literally just pick a number you want to start with and record it.
3 Calculate Weight of Fragrance Oil
So now you have a wax weight, W, and the fragrance load, f, so it’s time to do the math and find the fragrance oil weight, F.
It’s actually simple if you follow this formula. You’re solving for the weight, in ounces or grams, of oil to add to the wax blend.
The equation:
You divide f by 100 to make it a decimal. Using the example numbers from above:
Your final blend:
- Wax – 16.5 ounces
- Fragrance Oil – 1.32 ounces
With a total “blend weight” of 17.82 ounces.
The math is the same whether you are measuring your weight in ounces or grams (or pounds, if you’re a psychopath).
