Bottling Blends: The Essential Oil Maker's Guide to Glass
Bottling essential oils properly
Essential oils are concentrated, volatile and chemically active — which is why the container matters more here than in almost any other product category. The right bottle protects a blend from light, air and time, doses it precisely, and signals competence to your customer at a glance. This is the category PetraPack was founded on.
Why amber glass is the default
Glass first: essential oils are effective solvents and can degrade many plastics, so undiluted oils and high-concentration blends belong in glass. Amber glass adds UV filtering, helping protect light-sensitive aromatic compounds — the reason amber has been the apothecary standard for generations. Cobalt blue and green offer partial light protection with a distinctive look; clear and frosted suit diluted products stored away from sunlight. When in doubt, choose amber.
Air is the second consideration. Citrus and pine-family oils in particular oxidise on contact with oxygen, which changes their aroma and can make oxidised oils more likely to irritate skin. Two practical habits help: bottle sizes matched to how quickly the oil is used (a nearly empty large bottle is mostly air), and caps closed firmly between uses. Cool, dark storage does the rest.
Choosing the right top
| Closure | Best for | Why |
|---|---|---|
| Orifice reducer (dripulator) + cap | Undiluted essential oils | Drop-by-drop dispensing with minimal air exposure and no rubber in contact with the oil |
| Tamper-evident dropper | Diluted blends, serums, tinctures | Precise measuring with retail tamper evidence |
| Measured (graduated) dropper | Practitioner blends and dosing | Markings remove the guesswork from drops-per-dose |
| Roller ball | Pre-diluted pulse-point blends | Direct application for perfume oils and blends |
| Fine mist spray | Room, linen and body mists | Even dispersion for water- or alcohol-based sprays |
| Plain tamper cap | Storage and refills | Simple, secure, stackable |
A practical note: rubber-bulb droppers suit diluted products, but for neat essential oils the orifice reducer is the traditional choice — concentrated oils can degrade rubber over long storage.
Sizing your range
- 5ml — neat essential oils, absolutes, and samples.
- 10ml — the roller-blend standard and the most common size in aromatherapy retail.
- 15ml — the international standard for many single oils.
- 30ml–50ml — carrier-oil blends, facial oils, practitioner dilutions.
- 100ml — massage blends, body oils and mists.
- 250ml–1 litre — carrier oils, refills and clinic stock in Boston rounds.
Dilution: get the label right
If you sell pre-diluted rollers and blends, the dilution rate is a quality promise. Widely used aromatherapy conventions: around 1% for facial products and sensitive users, 2–3% for typical adult body blends, and lower for children, pregnancy, or oils with known maximums — with a patch test recommended. These are conventions rather than regulations, individual oils have their own limits, and a qualified aromatherapist's input is a worthwhile investment when formulating a retail range. State the dilution on the label: informed customers look for it, and it builds trust with everyone else.
Claims: stay on the right side of the line
The moment a label or listing claims a product treats, prevents or cures a condition, it risks crossing from cosmetics and fragrance into therapeutic-product territory under the Medicines Act — a different compliance regime. "Calming bedtime blend" describes a mood; "treats insomnia" is a therapeutic claim. Keep language sensory rather than medical, and if your business model depends on therapeutic claims, get regulatory advice before printing.
A label that carries its weight
- Botanical (Latin) names alongside common names
- Dilution percentage and carrier for blends; "undiluted" clearly stated for neat oils
- Batch or best-before information — oxidation makes freshness part of quality
- Safety notes: keep out of reach of children, avoid eyes, patch test
- Storage advice: cool, dark place, cap tightly closed
Choosing your bottles
Explore our essential oil and aromatherapy packaging — Euro dropper bottles from 5ml to 100ml, Petra roller bottles and orifice reducers, all by the tray at wholesale prices from our Tauranga warehouse. For pairing tops to bottles, see the compatibility guide, or call 07 262 1073 — we've been bottling oils since 2018.