In chemistry, the term Alcohol refers to the -OH functional group. That means whenever you have an oxygen with a single bond to both a hydrogen atom and something else, it's classed as an 'alcohol'.
It follows from this that you could make an infinite number of alcohols. Cedrol is one example which is naturally found in Cedarwood Essential Oil (A raw material used in perfumery):
Obviously, however, when you take a drink of vodka, you aren't ingesting a glass full of cedarwood oil. The alcohol found in alcoholic drinks also has a special name in chemistry; Ethanol.
Ethanol is the specific alcohol you get when you add an ethyl group (an arrangement of 2 carbon and 5 hydrogen atoms) to the alcohol -OH. Ethanol is found all over the place; from alcoholic drinks to biofuel to (you guessed it) perfume. In fact ethanol is so common, the term "Alcohol" is used in everyday life to refer to it.
So alcohol (ethanol) is used in perfumes?
Yes, precisely. Alcoholic perfumes (i.e. the usual spray on ones, not oil based ones) are made by diluting a fragrance concentrate (made up of things like aromachemicals and essential oils) with ethanol. The ethanol acts as a solvent which help create a sprayable consistency and helps the perfume disperse well on the skin and evaporate.
So, it follows then that when you're making an alcoholic perfume, you need to add some alcohol (ethanol) to your final product. Choosing which "Alcohol" to purchase for this often causes confusion amongst beginner perfumers. The purpose of this article is to clear up any confusion you may have.
If you've researched online which alcohol to add to your perfume, you may have come across some of the following terms:
- Denatured alcohol
- Trade specific denatured alcohol (TSDA SD-40b)
- Perfumer's alcohol & Formulator's alcohol
- Rubbing alcohol & Isopropyl alcohol
- Grain alcohol & Organic grain alcohol
- Everclear
- Vodka
- Witch Hazel
- Methanol
- Adding water to your perfume
We will now go through all of these terms and unpick exactly what they mean and if you should be using them in your perfume.
Denatured alcohol
Alcohol is considered "denatured" when it's made unfit for human consumption with the addition of poison, bad tasting chemicals or similar. You should never use something labelled solely as 'denatured alcohol' because there are many denaturants and you risk it containing poison and making your perfume toxic. The exception is cosmetic grade TSDA which is made specifically for use in cosmetic products.
Trade specific denatured alcohol (TSDA)
Not all denaturants are harmful. In fact, most perfume is made using a very specific type of denatured alcohol; cosmetic grade Trade Specific Denatured Alcohol (TSDA for short). The most widely used and recommended variant is SD-40b (a specific grade denatured with tert-butyl alcohol). Look for SD-40b TSDA to use as your perfumer's alcohol where possible.
Perfumer's alcohol & Formulator's alcohol
Perfumer's alcohol is the loose term for a blend of alcohol and some additives used as a base for perfumes. It's can be used as a placeholder term for TSDA or in reference to a blend intended to be used in place of TSDA. Some brands sell proprietary Perfumer's Alcohol blends in countries where you need a license to obtain TSDA such as the UK. This is an excellent alcohol to use for beginners when TSDA cannot be obtained.
Rubbing alcohol & Isopropyl alcohol
Rubbing alcohol uses the chemical "Isopropyl alcohol" instead of ethanol. Isopropyl alcohol is unsuitable for use in perfumes since it has a strong smell and is harsh on the skin. Furthermore, you may run into trouble dissolving your raw materials in it. Finally, rubbing alcohol as sold also contains added water which can interfere with your perfumes further. In short, never use rubbing alcohol for perfumery.
Grain alcohol & Organic grain alcohol
Grain alcohol is simply ethanol obtained by the fermentation of grains and other plants. It may also be "organic" if the source material was grown organically. It does not matter if your alcohol is grain or not for perfumery; what matters is that it's cosmetics grade and not diluted (it should be 95%+ ethanol content).
Everclear
Everclear is a brand of extremely high-proof grain alcohol (proof is a measure of alcohol content) made in the USA. Their strongest proof, 190-proof, corresponds to 95% ethanol and since it's food grade, it's suitable for use in perfumery. While this wouldn't be used in the industry (they use TSDA), you could use this as a beginner if you have trouble obtaining TSDA.
Vodka
Vodka is usually around 40% alcohol and not high enough proof for perfumery since you're looking for 95% + alcohol. Don't bother trying to use vodka to make perfumes from.
Witch Hazel
You may have read online about using With Hazel as an alcohol substitute for perfume making. This is incorrect information, ignore it entirely.
Methanol
Methanol is a different alcohol entirely than ethanol. It's extremely toxic and readily absorbed by the skin. You should never even consider using methanol in perfumes.
Adding water to your perfume
Some perfumers add water (only a couple of %) to make the perfume less harsh on the skin and help the 'lift' of the scent. On the other hand, it risks clouding the fragrance (due to the formation of a colloid for the chemists out there). If you add water, it must be 'deionised' or 'distilled' - that means regular tap water won't cut it. It's a personal choice; we don't use it at Lux & Terra but many perfume manufacturers do.
Conclusion
Use SD-40b if possible or another cosmetic grade denatured alcohol. If you cannot purchase this look for Perfumer's Alcohol from a trusted manufacturer with the stated use case of making perfumes from. You can also use 190 proof everclear if obtaining alcohol specifically made for perfumery is too difficult. Never use non-cosmetics or non-food grade denatured alcohol and never use a non-ethanol alcohol, especially not methanol. Adding a tiny amount of water is up to you; you should experiment to see if you like the effect since it's a personal preference. If you do so, make sure it's deionised and only use <5% in the final product as a maximum.
Bonus
Watch the article in video format
References
https://www.thoughtco.com/making-perfume-safely-3976069
https://www.karengilbert.co.uk/how-do-i-use-perfumers-alcohol
https://culinarysolvent.com/pages/perfumers-alcohol
https://culinarysolvent.com/blogs/ethanol/denatured-alcohol-vs-non-denatured-ethanol
https://basenotes.com/threads/rubbing-alcohol-is-fine-for-making-perfumes.289006/