Lactones are a class of perfumery compound that I have sought out despite not understanding them very well. I do enjoy a good creamy, milky scent, as long as it’s in the smooth, comforting register and not in excess. That said, not all lactones hint of dairy, and on their own, they’re not all that pleasant to be around. Here are a few.

Gamma octalactone

This is one whose reputation preceded its smell for me. I first heard of it and became interested because I had read that a simple fig accord can be made by blending gamma octalactone with Stemone®. For the longest time, I didn’t have this ingredient, so I used methyl laitone in its stead, which sort of works for an amateur novice. Earlier this week, this gap in my palette was filled, so I will try it next time I want fig in a mixture.

The main profile of gamma octalactone is supposed to be coconut, so I was very surprised to smell something spicy on the blotter with a strong undertone of ume shiso. A tart Japanese plum that is perfect for making wine and pairing with the gently minty herb that smells like cumin.

Gamma undecalactone

With aldehydes, apparently the higher the number of carbon atoms in the molecule, the better it smells. I’m not sure the same rule applies to lactones. Gamma undecalactone (which has 11 carbons) is the quintessential peach aroma, also used for apricot and other fruity notes, and quickly becomes plasticky and suffocating for me. Dosed right, it adds a buttery or creamy fruity aspect to a blend, but it tends to outlast its bottle-fellows in the drydown.

Milk lactone

This one is a dodecalactone—12 carbons of rich, concentrated dairy. Not for the faint of stomach. It’s not the soothing scent of fresh milk but of milk dregs, curdled and on the verge of sour. You can feel the thickness just by smelling and looking at it. When diluted to lower concentrations and after a chance to evaporate, it becomes more fruity and promises to play well with florals.

Methyl laitone

“Methyl Laitone 10% is one of the new spiro-lactones developed and patented by Givaudan.” Every supplier seems to repeat this description, copied from Givaudan’s own website. I haven’t been able to find much information about “spiro-lactones” that I can understand, but a little of this ingredient certainly goes a long way. It is mostly coconutty, but also coumarinic and even a bit like oatmeal on the blotter. I have used it a lot in small quantities in blends that I have wanted to soften, and it won’t weigh down a fragrance.

Jasmolactone

I had imagined that this would be a creamy floral on its own, but it’s more like a buttery pastry, dense like shortbread. Like other lactones, it may tend toward fruity more than floral. To be used in minute quantities.

Lactoscatone

I wasn’t sure what to expect from this one, but had read that it works wonders in floral blends when used carefully and with skill. It’s a bit like jasmolactone wearing steel armor. It has a similar “pastry” character and thankfully, despite the name, does not smell poopy to me. It is supposed to be animalic, like civet and ambergris. Rather, the piercing pungency is metallic to my nose, as though it had picked up a few tricks from a chance encounter with rose oxide.

Massoia lactone

I have been intrigued with massoia wood ever since I found it listed as a note in my beloved Givenchy Rêve d’Escapade. When I searched for the ingredient, only massoia lactone came up, and it was expensive, but I took a chance.

Apparently, massoia was the traditional source of lactones in perfumery before the move to synthetics. This specimen is natural, rectified from the essential oil.

Well. This is the culprit that filled the apartment—at least one room of it—with a stink. A somewhat familiar stink, fusty and almost like rancid oil. I have to force myself to inhale deeper past that initial pungency to get the more refined, light wood bark, suede-like fuzzy creaminess. Then the sour top notes seem to claim that they are just being fruity…

I have a feeling these will continue to be a challenge to use, but I am happy to expand my olfactory toolbox.