How long does homemade perfume last?

There are two answers. On skin, a homemade perfume lasts as long as its slowest materials stay audible, which depends on the formula and its strength, not on whether it was made at home. In the bottle, a finished perfume in alcohol, kept cool, dark and tightly closed, keeps its smell for a long time; the citrus top notes are the first thing to change, and heat, light and a half-empty bottle speed that up. Before either, it needs its rest: about two to four months, depending on strength.

How long does homemade perfume last on skin?

As long as a shop-bought perfume built the same way. Three things decide it: how much of the concentrate is made of slow materials, how long those materials stay readable, and the strength it is worn at. The catalog shows the spread: it lists Lemon Essential Oil at about four hours on a smelling strip, Hedione at about three days and Ambroxan at well over a week. A formula that is mostly citrus is gone early whatever it is labelled, and the same concentrate lasts longer as an eau de parfum than as an eau de toilette.

Be careful judging it on yourself. The nose adapts, and you stop smelling a perfume long before other people do. How to make a perfume last longer goes through all of this, including why a fixative alone does not fix it.

How long does homemade perfume last in the bottle?

There is no honest fixed date, because it depends on what is in it and how it is kept. A formula built on woods, musks and resins changes slowly. A citrus cologne changes soonest, because citrus oils and terpenes oxidise, and oxidation is what a bottle does with its time. A perfume is also only as fresh as its oldest material: a bergamot that was already a year old when you weighed it starts the clock early.

The catalog does not carry a shelf life for materials or perfumes. Where a supplier states one for its material, that is the best guide, and it is worth recording.

Why does it need to rest first?

Because a fresh blend is not yet one smell. The alcohol is raw, some materials are still dissolving, and a few are slowly reacting with each other. PerfuMate's maceration schedule rests an eau de toilette (up to 15 percent) for 60 days, an eau de parfum (up to 25 percent) for 90 and an extrait for 120, with a shake on day two, a first strip on day seven, a check at the halfway point, and a chill and filter at the end. A perfume that smells different in its first weeks is settling, not going off. What changes while it rests.

What changes as a perfume ages?

• The top goes first. Citrus reads flatter, then sharper or sour. The heart and base can smell exactly as they did.
• Colour deepens. A shift toward yellow or amber is normal with Vanillin, many naturals and some musks, and the catalog notes that Indole discolours formulas over time. Colour on its own is not a fault.
• A haze can appear in the cold. That is a material coming out of solution, not spoilage. Why a perfume turns cloudy.
• The level drops in a badly closed bottle. Alcohol escapes first, the top notes with it, and what is left is stronger and flatter than what you made.

How can I tell if a homemade perfume has gone off?

Compare it against itself. When you bottle a batch, keep a small sample of it full, sealed and in the dark, and do not open it. When you suspect the main bottle, dip a strip of each, label them underneath, and smell them as a blind pair at the first minute, ten minutes and an hour. If you cannot tell them apart, nothing has happened.

Without a reference, smell it on a strip rather than from the neck of the bottle, and trust the opening: a sour, sharp or rancid top, a plasticky note, or a top that has vanished while the base smells as it always did are the usual signs. Oxidation is not only a question of smell, either: IFRA restricts limonene and linalool by how oxidised they are, not by a percentage. If a perfume irritates your skin, stop using it, whatever its age.

How do I make it keep longer in the bottle?

• Start with fresh materials, stored well. How to store perfume materials.
• Bottle into small, full bottles. Use one and keep the rest sealed; the air in a half-empty bottle is what ages it.
• Keep it in a cool, dark cupboard, not on a sunny windowsill or in a warm bathroom.
• Close it tightly after every use.
• If you add an antioxidant such as BHT, which the catalog describes as a standard stabiliser in alcoholic perfumes, weigh it as a line of the formula so it is recorded.

A perfume oil follows the same rules, with one more: the carrier ages too. Jojoba and fractionated coconut oil keep well; kitchen oils go rancid.

PerfuMate's maceration journal dates each batch from the strength it was actually made at and shows when it is ready, and every batch stays on record with the day it was made, so the age of any bottle on your shelf is never a guess. How to keep track of perfume formulas. Start a formula, free.