Part 3: Introducing the ABC of Perfumery©

Updated: Apr 5, 2018


Click acá para la versión en Español

This is the 3rd part of a series aimed to:

  1. understand the ABC of Perfumery© system created by Steve Dowthwaite, owner of;

  2. see how it can help us organize and catalog our materials and,

  3. create and analyze perfumes.

If you didn't read the first two parts I strongly recommend you to do so. This is a link to PART 1 and this is a link to PART 2. If you want everything to make sense, PLEASE start reading from the beginning. So far we have learnt what's the name of each category of smell and which letter represents, we also explained the concepts of Odor Profile, Relative Impact and how interrelated these concepts are with the headspace and the creation of accords. Let’s dig deeper into this incredible system:

Odor Life:

Let's go back to the odor impact table we were working with last post:

Probably, as soon as you started working with the concept of relative impact, you realized that it changes its value over time, rendering materials weaker and weaker. So ANOTHER quantifying value is necessary to measure how long a materials odor lasts. We measure this in a smelling strip up to the point that the odor becomes weak and uncharacteristic of itself. Even though this measurement will vary depending in a plethora of conditions like humidity, ambient temperature, air-flow, amount used on the sample, etc.; still we can get effective comparative values between the different materials (assuming also that the conditions are the same, even though not the ideal).

So, dip the tip of a blotter in the product to evaluate and measure how long it last. Use fractions: 1 hour and 30 minutes will be 1.5 (this will make future math calculations easier —and yes, unfortunately there’s a tiny bit of math—). Smell the blotter as often as you can to evaluate whether the smell of the product is still the same or have became weak and uncharacteristic of itself. Is this a boring process? Yes, it is. But luckily you have to do it only once. Is it important? Yes. It will let you evaluate the "dynamics" of your perfume as it evolves over time and understand the interaction with the other materials..

Now I'm going to assume you went ahead and smell and timed the 5 materials of the last table. And probably you ended up with something like this:

Remember that we type time in fractions, so, 4 is 4 hours, 0.5 is half an hour, 0.1 is 6 minutes, etc. In the case of sandalwood, You can trust the value or sniff everyday a blotter for more than 6 months to realize that it is still there...

Now, let's create a graph where we have relative odor impact on the vertical axis and odor time on the horizontal axis. We then insert the different materials in there to see whats going on:.

First we put the Iso Amyl acetate, which has an impact of 1200, but after only 6 cannot smell it anymore. So at 0.1 the odor of Iso Amyl acetate became weak or uncharacteristic of itself. Let's add all the rest:

By looking at the graphical representation of how different notes evolve on a mix, we can also deduct that even though from the marketing point of view the concept of the famous triangle with top, middle and base notes is useful and easy to explain, it is NOT that accurate: Is sandalwood a TOP note? With the triangle, of course, you would say no, but...Of course it is!, in the sense that IT IS interacting, as you can see at the beginning of our graph, with all the other materials! The smell at the opening of the perfume would be somehow different if the sandalwood wouldn't be there. So that means that sandalwood NOT ONLY plays a role as a base note, towards the end of the odor life of the perfume but at the beginning and the middle life as well!

Now, with relative impact we measured how "hard" the headspace hit our nose, then we measured how long a smell last but we still need some kind of measurement that tells us, as an average, taking into account both impact and life, how "strong" a smell is.

Well, let's go back to a graph, this time only adding the linalool, as an example:

The painted area represents what we are trying to achieve: how "strong" a smell is. We will call this variable odor strength, but how do we calculate it?

Easy peacy...basic geometry.!.

Since it is a triangle, we can calculate the area of the rectangle formed with the dotted lines and divide it by 2. As you can see, One side of the rectangle is our measurement of the odor life, the other side is the measurement of the odor impact. so we multiply those values (that gives us the area of the rectangle) and we divide it by two (we get half of it, the triangle).

What do we get?

We get the strength of that material and we measure it in odor units:

Linalool: 100 (impact) x 4 (odor life) / 2 = 200 odor units.

Now, let's put everything in a table:

Enough math. Why don't we jump for now into a more attitudinal, behavioral and psicological setting?

Training our sense of smell: Getting Synesthesia back

Before you dive into your next smelling session, let's review first some basics about the process of train our sense of smell:

  • The worst place to smell: Our lab. PLEASE, get out of there, go outside, where the sun shines and the air graze your face. You need your nose and your mind to be relaxed, encumbered and clear.

  • Use of blotters:

o Try to use always the same kind of paper (Thinner strips are better for

analytical smelling, thicker ones for presentation of samples.

o Dipping the strip 0.5 cm (0.2 inches) along the strip is more than enough. Let

the product spread until it is not wet. And THEN smell.

o For sniffing, hold it around ½ inch from your nose.

o Bend the tip of the blotter at about 2 inches. This will help you avoiding

touching your nose when you are smelling and, let's be honest, you will look

cool and more professional, like you know what you are doing. LOL, Just

kidding -or not-.

  • Be sure to be relaxed and not wearing any fragrance. Do not drink coffee or strong drinks right before or while smelling. Sitting down is probably better than standing, but experiment both ways and determine how do you feel and which way is better for you.

  • Method: Sniff and evaluate. Sniff for a really short period of time and try to think about the smell, mentally evaluate it and memorize it. Do not keep inhaling like a maniac. Your lungs are useless for this. All your smell receptors are inside your nose, really close to where your sample is and NOT on your lungs. Doesn't matter how much you try, the smell WON'T get there...The shorter and smoother the sniff, the better. Use your mind, analyze the smell. Record it. You will be surprised how well our mind can be trained to learn new things. Even if you think you will not be capable or that you are not intelligent...your mind learns regardless...LOL, just kidding.

  • Make notes. As many as you can.