Seeking Advice on Storing My Perfume Materials in the Fridge

Hi everyone,

I know this is a commonly asked question, but I’ve seen a wide range of answers, from "you don’t need to store anything in the fridge" to "just store the citruses, naturals, or aldehydes," and even "store everything containing or derived from terpenes". Given that some materials are more reactive than others - even within the same functional group - and that I don’t have much knowledge about the shelf-life of my materials (I'm just starting out), I’m hoping to get some advice on my specific collection. I'd appreciate any guidance, if anyone is kind enough to help out.

I don’t own a mini-fridge, just a regular fridge in my kitchen. My plan is to store all materials in an air-tight food storage container. Ideally, I’d like to avoid having to replace any materials due to deterioration for at least 3 years (I have at most 10g of each material) - but, of course, the longer they last, the better!

I’m not very versed in chemistry, but I tried to categorize everything into three groups: citrus-related essential oils (which I think definitely need to go in the fridge), aldehydes, and non-aldehydes (based on my limited knowledge, i.e., whether the name contains "Aldehyde" or ends in "al").

Aldehydes?

1. Aldehyde C-9 (Nonanal)
2. Aldehyde C10 (Decanal)
3. Aldehyde C-11 undecylenic
4. Aldehyde C-12 MNA
5. Aldehyde C-18
6. Alpha Hexyl Cinnamic Aldehyde
7. Anisic Aldehyde
8. Benzaldehyde
9. Beyond Hivernal (Firmenich) << "contains Florol, Mayol, Hivernal Neo (an aldehyde?), and a proprietary captive"
10. Bourgeonal
11. Citral
12. Helional
13. Hydroxycitronellal
14. Lilial
15. Lyral
16. Mandarin Aldehyde 10% Citr.
17. Muguissimo (Firmenich) << "fresh and clean muguet aldehyde"
18. Myrac Aldehyde
19. Safranal
20. Triplal (Trital) 10%

Non-Aldehydes?, Non-Citrus E.O.

1. Acetanisole
2. Allyl Amyl Glycolate
3. Allyl Hexanoate
4. Amarocit (Methyl Pamplemousse)
5. Amber Xtreme 1%
6. Ambrettolide
7. Ambrocenide
8. Ambroxide 10%
9. Amyl Salicylate
10. Anthamber
11. Auralva (Aurantiol)
12. Bacdanol
13. Benzoin Siam res. 50% EtOH
14. Benzyl Acetate
15. Benzyl Salicylate
16. Calone 10%
17. Cashmeran
18. Cassis Base 345B
19. Castoreum synth.
20. Cedarwood Oil Super Rectified
21. Cedarwood Virginia EO
22. Cedarwood White
23. Cedramber
24. cis-3-Hexanyl Salicylate
25. Cis-3-hexen-1-ol FCC No 121 1%
26. cis-6-NONEN-1-OL No 337
27. Citronellol 95
28. Civet synth.
29. Clearwood
30. Coumarin 10%
31. D-Limonene (nat.)
32. Damascone Beta
33. Dihydro Ionone Beta
34. Dihydroeugenol
35. Edenolide
36. Ethyl Caprylate
37. Ethyl Linalool
38. Ethyl Maltol 10%
39. Ethyl Vanillin 20%
40. Ethylene Brassylate
41. Eugenol (nat.)
42. Exaltolide
43. Floralozone 10%
44. Galaxolide 50% IPM
45. Galbex 183 EB
46. Geraniol Pur
47. Guaiacwood EO Guatemala
48. Habanolide Subst
49. Hedione
50. Indoflor 10%
51. Iso E Super
52. Isobornyl Acetate
53. Isobutavan 10%
54. Javanol
55. Kephalis
56. Khusinil
57. Kohniool
58. Labdanum abs. 50% EtOH
59. Lavandin Abrialis EO
60. Linalool
61. Linalyl Acetate Coeur
62. Lindenol
63. Magnolan
64. Methyl Ionone Alpha Extra
65. Methylionone Gamma
66. Nerolione
67. Norlimbanol
68. Patchouli EO DM Indonesia
69. Patchouli light EO
70. Phenyl Ethyl Acetate
71. Phenyl Ethyl Alcohol
72. Polysantol
73. Raspberry Ketone
74. Romandolide
75. Santaliff
76. Stigemone (Stemone)
77. Styrallyl Acetate
78. Styrax resinoid 10%
79. Sylvamber
80. Timberol
81. Timbersilk
82. Tonalide
83. Vanillin
84. Veramoss 20%
85. Verdox (OTBCHA)
86. Vertofix Coeur
87. Vetiverol Extra
88. Zenolide

Citrus-Related Essential Oils

1. Lemon Bio EO Italy
2. Mandarin Green Bio EO Italy
3. Mandarin Red Bio EO Italy
4. Mandarin Yellow Bio EO Italy
5. Orange EO Brazil
6. Petitgrain EO Paraguay

Another question:
The raw materials I bought came with caps that have these plastic rings inside (see the cap on the left in the picture). When I screw the cap on, there’s quite a bit of resistance, and the ring seems to press against the bottle walls. Are these caps sufficient, or would you recommend replacing them all with polycone-lined polypropylene caps like the ones I bought for my dilution bottles (see the right cap in the picture)?


I’d be really grateful for any advice you can share!

Most things actually last quite long even without a fridge, however, here are some personal observations on some of the materials that you own:

Aldehydes C9-C12: Supposedly sensitive and could benefit from refrigeration. I've kept mine unrefrigerated for 4 years though and they don't smell any different.
Lilial, Bourgeonal, Benzaldehyde, Hydroxycitronellal: Those will oxidize rather quickly, in the order listed. For Lilial and Bourgeonal, consider diluting them with some solvent such as DPG (50% should be enough) and/or add small amounts BHT (antioxidant).
Citrus Oils: Some of them are volatile and could lose some freshness or develop off-putting notes. I personally didn't bother refrigerating them until now and haven't noticed anything of the sort.
Ionones: I've read from other members that they can be sensitive but mine are still ok after 4 years (at least the Alpha, Alpha Isomethyl, Beta, Dihydro Beta and Methyl Ionone Gamma - some others I've acquired more recently, so I can't really comment). The only Ionone that's SUPER SENSITIVE in my experience is Allyl Ionone (or Hexalon), which started smelling fishy after owning it for only 3 months. Next time I get a vial, it's going in the fridge from day 1 with some BHT added.

The rest of your materials you can store without issues even if the room reaches temperatures of up to 30 degrees Celsius.

As for the caps, the ones on the right are what you ideally want. The ones on the left might or might not be sufficient, depending on how China-tier they actually are.

orestes13 said:

Most things actually last quite long even without a fridge, however, here are some personal observations on some of the materials that you own:

Aldehydes C9-C12: Supposedly sensitive and could benefit from refrigeration. I've kept mine unrefrigerated for 4 years though and they don't smell any different.
Lilial, Bourgeonal, Benzaldehyde, Hydroxycitronellal: Those will oxidize rather quickly, in the order listed. For Lilial and Bourgeonal, consider diluting them with some solvent such as DPG (50% should be enough) and/or add small amounts BHT (antioxidant).
Citrus Oils: Some of them are volatile and could lose some freshness or develop off-putting notes. I personally didn't bother refrigerating them until now and haven't noticed anything of the sort.
Ionones: I've read from other members that they can be sensitive but mine are still ok after 4 years (at least the Alpha, Alpha Isomethyl, Beta, Dihydro Beta and Methyl Ionone Gamma - some others I've acquired more recently, so I can't really comment). The only Ionone that's SUPER SENSITIVE in my experience is Allyl Ionone (or Hexalon), which started smelling fishy after owning it for only 3 months. Next time I get a vial, it's going in the fridge from day 1 with some BHT added.

The rest of your materials you can store without issues even if the room reaches temperatures of up to 30 degrees Celsius.

As for the caps, the ones on the right are what you ideally want. The ones on the left might or might not be sufficient, depending on how China-tier they actually are.

Click to expand...

This is exactly the kind of personal observations I was looking for, much appreciated - thank you!

Would putting the Lilial, Bourgeonal, Benzaldehyde and Hydroxycitronellal into a fridge slow down the oxidation process? Or any idea if diluting these materials to 50% in 96% ethanol (I don't have DPG) will help?

denden_22 said:

This is exactly the kind of personal observations I was looking for, much appreciated - thank you!

Would putting the Lilial, Bourgeonal, Benzaldehyde and Hydroxycitronellal into a fridge slow down the oxidation process? Or any idea if diluting these materials to 50% in 96% ethanol (I don't have DPG) will help?

Click to expand...

I caught my Lilial and Bourgeonal when they were already starting to oxidize, so I didn't really care that much about refrigerating them at that point. I just added solvent to slow down any further oxidation, which seems to have worked. Honestly, I just need to toss them and buy new stock but they still seem to smell the same, so I keep using them even though the walls of the vials have some small sticky lumps attached to them. I'm assuming if you buy new stock and dilute it to 50% immediately, it's probably going to be fine. With Hydroxycitronellal and Benzaldehyde I only notice some stickiness when unscrewing the cap. The liquid inside is perfecly clear. I'm unsure if diluting in ethanol works the same or if refrigerating them actually helps with oxidation, so I'll let someone with knowledge in chemistry answer that.

My rule of thumb is, I put everything in the fridge that is a natural essential oil. And for the aroma molecules I look on the chemical structure, if it has an unsaturated double or even tripple bond in its structure, an aldehyde group or other parts that are prone to oxidation, then I put it in the fridge. If not, then I keep it at room temperature. No need to dilute, keep them as original as possible. One exception to my rule is, if the material will precipitate in the fridge (like my heliotropin solution).
But even in the fridge the materials will not last forever. My one year old cold-pressed lemon oil smell more like turpentine in the meantime.
By the way, the (so-called) aldehyde C-18 is fine at room temperature because it is not actually an aldehyde. But it also depends on your room temperature. I live on the top floor and it gets really hot in the summer, which is not good for any material.

I'll just add that, when talking about absolutes, you should be wary of partial crystallisation.
for example: I have a bottle of lavender abs. which is fully liquid at room temperature, and refrigerated it also seems liquid, but upon closer inspection you can see a layer of white-ish solid stuck to the bottom (which is not obviously visible through a dark amber bottle). Low-solubility fractions dropping out of solution can change the scent profile. This is why I don't refrigerate this material - even though I have a general policy of refrigerating naturals.