Working with perfumery requires using various techniques, and one that we face early on is working with solid materials. I see people often posting in perfumery forums about this very subject, because it can be quite daunting. However, it is actually not as difficult as it seems. When I started on my perfumery journey, I was originally puzzled as to how to dissolve solids. Since some people posting in the forums seemed to dilute their solids, yet I had formulas requiring these materials at 100%, it only added to the confusion.
This brings me, briefly, to the subject of dilution of your perfumery materials. One of the myths perpetuated is that you have to dilute all your materials to 10%. This is not necessarily accurate, nor does it work for everyone. While some like to do this to learn how specific materials smell in diluted form, I never subscribed to this method. I tend to be practical, and the thought of having every single material diluted to 10% alongside full-strength versions was out of the question for me, especially because many materials will never be used in a 10% dilution. Materials such as Hedione, Phenyl Ethyl Alcohol (PEA), Lavender and Bergamot are some I have never used diluted. Now that I have over 700 materials, I am very thankful I opted not to go that route! Scent strips work for me if I want to sample a material in various stages of drydown. In the beginning of your perfumery journey, it can be all too easy to follow someone else’s path, which in the end may not suit you. Eventually, the best way to work with perfumery is the way that works best for you, and ‘right’ and ‘wrong’ can be subjective, but there are some tried and tested methods that work for most.
I know several perfumers, none who dilute their materials except those that need it due to scent strength (such as Aldehydes). Over time, one learns what materials need dilution and which ones are generally used at 100%. Some materials such as aldehydes, civet, ribes mercaptan, cis-3-hexenol, are extremely strong, requiring only trace amounts in a formula. To incorporate them into a formula in such small amounts, we generally dilute these materials into a 50%, 10% or 1% strength dilution. A much larger number of perfumery materials are generally used at 100%. However, that is a subject for a whole other post. On this particular post I’d like to go back to discussing solid materials and why dilution of these materials is not usually necessary, unless needed due to scent strength.
While many materials used by a perfumer come in liquid form, you will quickly encounter solid materials. Materials such as Musk Ketone, Calone, Ambroxan, Tonalide, Cedrol, Benzophenone, to name a few, are usually sold in powder, crystalline or even ‘rock’ form. You will also find some materials like Cinnamic Alcohol and Guaiacwood, which turn into a waxy solid at room temperature. These are materials that turn back to liquid form with gentle heating. Other materials such as Benzyl Cinnamate and Terpineol can be quite solid, but will also revert to liquid form upon heating. Some materials sold in powder form or small crystalline form are Musk Ketone, coumarin, vanillin and ethyl vanillin.
Suppliers tend to sell some of these materials in both solid and diluted form. Ambroxan is such an example, sold in solid form and also at 40% dilution, but I do not usually like to buy materials diluted because at one point or another you will need to use a material in its full-strength form; even materials as strong as aldehydes. If at any point I need to dilute them, I prefer to do it myself. If you do choose to buy some materials diluted, make sure you also have the material in its full-strength form. Ambroxan is a good example, because it is difficult to dilute, so it is one that I have purchased both in solid and diluted forms.
The issue with some materials, like aldehydes or Bitter Almond Oil (which is 99% Benzaldehyde), is that they oxidize quickly, so diluting them in perfumer’s alcohol and storing them in a refrigerator will help them last much longer. There are some materials that, while not needing dilution, will need refrigeration to last longer. I will cover this more in depth on another post, but materials such as the aforementioned aldehydes, or citrus oils such as lemon, orange, bergamot, need refrigeration.
Solid perfumery materials have various specific points at which they will dissolve and this can be extremely confusing unless you’re a chemist. I am not a chemist and at some point, I drew the line as to how far I wanted to get into scientific specifics. Discussions with others who were perfumers or learning the craft gave me some useful hints, but ultimately trial and error was what taught me how to work with solids.
Some materials will not dissolve in alcohol, but will dissolve in dipropylene glycol (DPG/DIPG), Isopropyl Myristate (IPM), Benzyl Benzoate, etc. Again, it all goes back to chemistry. Knowing some chemistry might save you the trouble of the ‘hit or miss’ method. If you’re so inclined, I certainly encourage it. Some materials will need heating to dilute into your base, while others will not even budge with heating. Since I generally work with perfumer’s alcohol as my perfume base, it is my go-to for dissolving tough solids when I need to. Some things like vanillin, however, did not dissolve in alcohol, so alternatives like DPG or IPM worked best. Sometimes heating will encourage a solid to dissolve once in a base. But, let me go back to using solid materials at full strength.
Since I mentioned using materials at 100%, you may wonder how I would do that with solids, as this would mean not dissolving them at all before adding them to my mix. The answer to that lies in what I mentioned before, about materials having different points at which they will dissolve. When you create a perfume base, you’re mixing many molecules, all with different dissolution points. When you have them all together, they become a perfect base in which a solid will dissolve. I am yet to find a solid that has not dissolved in my perfume mixture. I am sure there are, I just have not dealt with them yet in my six years of doing this. Even Ambroxan, otherwise difficult to dissolve, will dissolve in a perfume blend. I simply add the solids to my formula and I have yet to encounter materials that, given a day or so, will not fully dissolve into the blend. The other molecules make sure of it. The key is being able to get the solid in an easier to use form, such as a powder, so that you can then add it to your formula.
For some materials that will not liquify upon heating, or of which I need a small amount so I do not want to bother heating, I use small clay sculpting tools. These can be used to scrape, prod and puncture materials so that I can create small amounts of crystals or powder I can then scoop up and add to my blend. I clean these tools after each use with inexpensive vodka that I keep in a spray bottle by my work desk. You want to make sure not to cross-contaminate your materials by dipping the tool from one to another without cleaning them first.
I am still getting around to finding a tiny spoon to scoop the materials with, so I continue to use a paper scent strip to do it. I simply fold the paper strip long-side to create a channel. I then use that to scoop the material and slide it into the bottle on my scale in which I am blending the perfume compound. This works especially well for crystalline or powder materials like Musk Ketone or Coumarin. I know some perfumers who also use this simple method. A toothpick sometimes helps encourage the material to slide down from my ‘paper strip scoop’ down into the bottle. Materials like Cinnamic Alcohol, which solidify into a waxy solid, I can scoop with a clay sculpting tool when I need a small amount and I do not want to heat it up. For larger amounts, I will heat the material into liquid form.
Other materials like Tonalide come in tiny ‘pebbles.’ I simply pick these with a tiny tweezer or my fingers, and add them to the blend one at a time, until I reach the desired weight on my scale. However, I would recommend care when handing perfumery materials with your bare hands. Some will sting or cause a rash when pure and undiluted. While some people wear gloves when they work with perfumery, I cannot work well with them on, so I do not. But you also do not want to be handling these materials and then touching your eyes or face by accident — this has been known to happen. I always recommend washing your hands thoroughly after working with perfumery. I suggest adding liquid soap to your hands before using water. This is because most perfumery materials are not water soluble and if you add water first, you are only making sure the materials will spread and not wash off. Once you worked the liquid soap evenly over your hands, then add water and wash normally.
Once the solids are added to the blend, swirling (not shaking) will encourage dissolution. Materials like Cetalox or Coumarin will spin around, seemingly not willing to dissolve. In a few hours or by the next day, you will see them completely dissolved into your mix. Some more swirling works.
When it comes to solids like Alpha Terpineol or Cinnamic Alcohol, which easily turn back to liquid form with heating, I simply use hot water to do the job. Using a kettle (I prefer an electric one, which is quick), boil some water. Once the water is hot, add some into a glass Pyrex measuring cup and add cold tap water to reach a temperature that is still very hot, but not scolding. Insert the capped bottle with your perfume material into the water and then adjust the water to cover ¾ of the bottle, but keeping the water away from the top. You want to make sure you leave at least ¼ inch or more from the top of the bottle, as you do not want any risk of getting water into your material. Again, the bottle containing your perfume material should be capped. If water gets into the bottle, it will ruin your material. Honestly, with a little care, this never need happen. In my six years of working with perfumery, it has never happened to me. Just be careful. Of course, now that I wrote this, watch it happen next time I do this!
I generally like to set up my solid materials that need liquifying in a hot water bath when I start mixing a formula, to save time. Once I have all my bottles lined up in order before me on my work desk, I take the ones that need heating, put them in their water bath and leave them there until I am ready for them. I will then go ahead and mix all my other materials and, at the end, retrieve the other materials from their water bath. By then they are already in their liquid form and ready for use. If any of these materials that I heated up is normally refrigerated, I will let it return to room temperature before putting them in the refrigerator, to avoid condensation inside the bottle. As a rule, it is never a good idea to go directly from cold to hot or vice-versa.
Some materials are rather viscous. Undiluted Galaxolide or Benzoin come to mind as well as some absolutes like tobacco or violet leaf. They’re thick, viscous and are not easy to work with undiluted, but there are times in which you’ll need them at full strength. Taking Galaxolide as an example, I generally will let it pour, slowly, into my mix. Heating slightly beforehand will help it flow more smoothly. Once it starts flowing into the bottle in which I am blending my formula, I use the tip of a small plastic pipette to control the flow. I juggle staring at the weight on the scale and the bottle the material is pouring out of. It takes practice. As I get close to the amount I need, I quickly make sure to slow the pouring to a bare trickle and then, using the tip of the pipette, I stop the flow when I reach the right weight I need. Needless to say, materials like Galaxolide and Benzoin are often used at 50% dilution to make the job easier, but I have also used them undiluted. When adding these types of undiluted materials to your blend, it is not uncommon to see them sink to the bottom of your bottle and sit there, in a puddle, even as you swirl. Within a few hours or a day, you will see them fully dissolved. Swirling your bottle gently, every so often, helps speed up the process.
Since I mentioned above how I like to work, and I cover this extensively in my Creating page, I figured I would briefly explain that here. For a detailed explanation, please see my other page. I generally will spend much time doing research before I put together a formula, then I write it on a specially designed sheet (see my Creating page). Once I have the formula all laid out, I go to the room in which I keep all my perfumery materials and retrieve the ones I need. I do not keep these materials in the same room in which I work, because the scent of the materials is overwhelming and interferes with my work.
I have a tray that I use specifically for my work. I gather all the materials I need and put them on my tray and then take it into my work space. I then line up the bottles of materials before me on my desk, in the order I have them listed on my formula sheet. This helps me from wasting time trying to find each material as I work, and also makes sure I do not pick up the wrong one by mistake. I will always double check the material in my hand with what is on my formula sheet. I also triple check the amount I am supposed to add to the bottle on the scale. Once I am done adding each material into the bottle, it goes back on the tray. In this way, in the rare case that I am interrupted I will not have to second guess whether I already added the material or not. If you mess this up, you have to start from scratch. Any doubt at all as to whether you added the material or not and your work is over and you have to start again. So, you can see how the tray helps tremendously. If a material is back on the tray, that tells me I am done with it. Focus is imperative once you start blending a formula.
I hope this post helps make your working with solid perfumery materials more enjoyable. If you’re just starting out, try to blend your materials as I mentioned, directly into your formula. I am sure you will never look back.