Essential Oil Encyclopedia — Complete Guide to Therapeutic Oils & Aromatherapy

Essential Oil Encyclopedia — Your Complete Guide to Therapeutic Oils & Aromatherapy

Essential oils are the concentrated aromatic essences of plants — extracted from flowers, leaves, bark, roots, resins, and seeds through precise distillation and cold-pressing methods. This encyclopedia is your authoritative reference for understanding, selecting, and using essential oils safely and effectively, curated by Blueberry Botanicals from Kerala's botanical heritage..

Essential oils are potent plant extracts. Always dilute before topical application. Not intended to diagnose, treat, cure, or prevent any disease. Consult a qualified aromatherapist or healthcare practitioner before use, especially during pregnancy, lactation, or if on medication.

What Are Essential Oils? A Complete Definition

Essential oils are volatile aromatic compounds found in the glands, hairs, veins, and cells of plants. They are called "essential" not because they are indispensable, but because they carry the "essence" — the characteristic fragrance and therapeutic properties — of the plant from which they are derived.

Unlike fixed oils (such as coconut or sesame oil), essential oils are volatile — they evaporate quickly at room temperature and do not leave a greasy residue. This volatility is what makes them effective in aromatherapy, where inhalation of the aromatic molecules triggers physiological and psychological responses.

In Ayurvedic tradition, aromatic plants and their essences have been used for thousands of years in Gandha Dravya (aromatic substances) for ritual, therapeutic, and cosmetic purposes.

How Essential Oils Are Extracted

Method Process Best For Quality Impact
Steam Distillation Steam passes through plant material into a condenser Most herbs, flowers, leaves, bark Gold standard — preserves most therapeutic compounds
Cold Pressing Mechanical pressing without heat Citrus peels Excellent — no heat degradation
CO2 Extraction Supercritical CO2 at low temperature Delicate flowers, resins, spices Superior — most complete extraction
Solvent Extraction Chemical solvents produce absolutes Jasmine, rose, tuberose Good — may contain solvent traces
Enfleurage Fat absorbs fragrance from delicate flowers Jasmine, tuberose (historical) Excellent but extremely labour-intensive
Hydrodistillation Plant material submerged in water and boiled Roots, seeds, hard plant material Good — suitable for dense material

Essential Oil Quality — How to Identify Genuine Therapeutic-Grade Oils

Quality Indicator What It Means Why It Matters
Botanical name on label Full Latin binomial (e.g., Lavandula angustifolia) Prevents species substitution and adulteration
Country of origin Specific country or region of cultivation Terroir affects chemical composition and potency
Extraction method Steam distilled, cold pressed, CO2 extracted Determines purity and compound profile
Part of plant used Flower, leaf, bark, root, resin, seed Different parts yield different chemical profiles
Batch number Unique identifier for each production batch Enables traceability and quality verification
GC/MS testing Gas chromatography/mass spectrometry analysis Verifies chemical composition and detects adulteration
Dark glass bottle Amber or cobalt blue glass Protects from UV degradation

Common Adulteration Practices to Avoid

  • Dilution with carrier oils: Adding vegetable oils to increase volume without disclosure
  • Synthetic fragrance addition: Adding synthetic aroma chemicals to boost or standardise scent
  • Species substitution: Using a cheaper species with a similar name (e.g., lavandin instead of true lavender)
  • Rectification: Removing or adding specific compounds to alter the chemical profile
  • Extending with alcohol: Adding ethanol to increase volume

Essential Oil Safety — Complete Safety Guidelines

Dilution Guidelines

Application Recommended Dilution Drops per 10ml Carrier Oil
General adult body use 2–3% 4–6 drops
Facial application 0.5–1% 1–2 drops
Children (6–12 years) 0.5–1% 1–2 drops
Elderly or sensitive skin 0.5–1% 1–2 drops
Acute localised use Up to 5% Up to 10 drops
Bath (dispersed in carrier) 1–2% 5–10 drops in bath dispersant

Contraindications and Cautions

  • Pregnancy: Many essential oils are contraindicated during pregnancy. Always consult a qualified aromatherapist.
  • Epilepsy: Camphor, rosemary, sage, eucalyptus may trigger seizures in susceptible individuals.
  • High blood pressure: Stimulating oils (rosemary, thyme, black pepper) should be used with caution.
  • Photosensitivity: Citrus oils cause photosensitisation — avoid sun exposure 12–24 hours after topical application.
  • Children under 2: Do not use without professional guidance.
  • Pets: Many essential oils are toxic to cats and dogs. Never diffuse in enclosed spaces with pets.
  • Medication interactions: Consult a healthcare practitioner if on prescription medication.

Patch Test Protocol

Dilute to 1% in carrier oil, apply to inner forearm, leave 24 hours, check for redness or irritation before full use.

Carrier Oils — The Essential Companion

Carrier Oil Botanical Name Skin Type Key Properties Traditional Use
Coconut Oil Cocos nucifera All types, especially dry Deeply moisturising, antimicrobial Kerala's primary traditional carrier
Sesame Oil Sesamum indicum All types, especially Vata Warming, deeply penetrating, antioxidant Primary Ayurvedic massage oil base
Sweet Almond Oil Prunus dulcis Normal to dry Light, nourishing, vitamin E rich Traditional skin softener
Jojoba Oil Simmondsia chinensis All types, especially oily Liquid wax, balances sebum, long shelf life Modern standard for facial blends
Castor Oil Ricinus communis Dry, mature Thick, deeply moisturising, hair growth support Traditional Kerala hair oil base
Rosehip Oil Rosa canina Mature, scarred, hyperpigmented High in vitamin C and essential fatty acids Modern skin regeneration standard

Essential Oils A–Z — Complete Reference Guide

Oil Botanical Name Extraction Traditional Use Ayurvedic Dosha Safety Notes
Bergamot Citrus bergamia Cold pressed Uplifting, skin care, stress relief Reduces Pitta Photosensitising — use FCF version for skin
Black Pepper Piper nigrum Steam distilled Warming, circulation, digestive support Reduces Kapha & Vata Dilute well — can irritate sensitive skin
Camphor Cinnamomum camphora Steam distilled Cooling, respiratory, pain relief Reduces Pitta & Kapha Avoid in epilepsy, pregnancy, children under 2
Cardamom Elettaria cardamomum Steam distilled Digestive, warming, aphrodisiac Reduces Vata & Kapha Generally safe at normal dilutions
Cedarwood Cedrus atlantica Steam distilled Grounding, hair care, insect repellent Reduces Kapha & Vata Avoid in pregnancy
Clove Bud Syzygium aromaticum Steam distilled Analgesic, antimicrobial, dental care Reduces Kapha & Vata High dermal sensitiser — use at max 0.5%
Eucalyptus Eucalyptus globulus Steam distilled Respiratory, antimicrobial, cooling Reduces Kapha Avoid near face of children under 10
Frankincense Boswellia serrata Steam distilled Skin rejuvenation, meditation, anti-inflammatory Reduces Vata & Kapha Generally safe — excellent for mature skin
Geranium Pelargonium graveolens Steam distilled Balancing, skin care, hormonal support Reduces Pitta Generally safe — avoid in first trimester
Ginger Zingiber officinale Steam distilled Warming, digestive, circulation Reduces Vata & Kapha Photosensitising — dilute well
Jasmine Absolute Jasminum grandiflorum Solvent extraction Uplifting, skin care, aphrodisiac Reduces Vata Absolute — not for internal use
Lavender Lavandula angustifolia Steam distilled Calming, skin healing, sleep support Reduces Pitta & Vata One of the safest oils — can be used neat in emergencies
Lemon Citrus limon Cold pressed Uplifting, cleansing, skin brightening Reduces Kapha Photosensitising — avoid sun after topical use
Lemongrass Cymbopogon citratus Steam distilled Toning, insect repellent, muscle care Reduces Kapha & Pitta Dermal sensitiser — use at max 0.7%
Neroli Citrus aurantium var. amara Steam distilled Skin regeneration, anxiety, mature skin Reduces Pitta & Vata Generally safe — excellent for sensitive skin
Patchouli Pogostemon cablin Steam distilled Grounding, skin care, anti-inflammatory Reduces Vata Generally safe — improves with age
Peppermint Mentha piperita Steam distilled Cooling, digestive, headache relief Reduces Pitta & Kapha Avoid near face of children under 10; avoid in pregnancy
Rose Otto Rosa damascena Steam distilled Skin care, emotional balance, aphrodisiac Reduces Pitta Generally safe — one of the most precious oils
Rosemary Rosmarinus officinalis Steam distilled Hair growth, mental clarity, circulation Reduces Kapha & Vata Avoid in epilepsy, high blood pressure, pregnancy
Sandalwood Santalum album Steam distilled Skin care, meditation, grounding Reduces Pitta & Vata Generally safe — Indian sandalwood is the classical standard
Tea Tree Melaleuca alternifolia Steam distilled Antimicrobial, skin care, first aid Reduces Kapha & Pitta Do not ingest — toxic to pets
Turmeric Curcuma longa Steam distilled / CO2 Anti-inflammatory, skin brightening Reduces Kapha & Vata May stain — dilute well
Vetiver Vetiveria zizanioides Steam distilled Grounding, cooling, skin care Reduces Pitta Generally safe — thick viscosity, warm before use
Ylang Ylang Cananga odorata Steam distilled Relaxing, aphrodisiac, hair care Reduces Pitta & Vata Use sparingly — can cause headache at high concentrations

Essential Oil Blending — The Art and Science

The Note System

Note Evaporation Rate Role in Blend Examples
Top Notes Fast (1–2 hours) First impression, uplifting, energising Lemon, Bergamot, Peppermint, Eucalyptus
Middle Notes Medium (2–4 hours) Heart of the blend, balancing Lavender, Geranium, Rosemary, Cardamom
Base Notes Slow (4–6+ hours) Depth, fixative, grounding Sandalwood, Vetiver, Patchouli, Frankincense

Classic blending ratio: 30% top notes + 50% middle notes + 20% base notes.

Blending by Therapeutic Intention

Intention Recommended Oils Suggested Blend
Relaxation & Sleep Lavender, Vetiver, Sandalwood 3 drops Lavender + 2 drops Vetiver + 1 drop Sandalwood in 10ml carrier
Energy & Focus Peppermint, Rosemary, Lemon 2 drops each in 10ml carrier
Skin Brightening Frankincense, Neroli, Rose Otto 1 drop each in 10ml rosehip carrier
Hair Growth Rosemary, Cedarwood, Peppermint 3+2+1 drops in 10ml castor carrier
Stress Relief Bergamot, Lavender, Frankincense 2+2+1 drops in 10ml carrier
Respiratory Support Eucalyptus, Peppermint, Camphor, Tea Tree Diffuse 2 drops each — not near children's faces

Aromatherapy Methods — How to Use Essential Oils

Method How To Use Best For Cautions
Diffusion 5–10 drops in ultrasonic diffuser Mood, respiratory, air purification 30–60 min sessions; ventilate; keep away from pets
Direct Inhalation 1–2 drops on tissue, cup over nose Immediate mood or respiratory effect Do not touch eyes
Steam Inhalation 2–3 drops in hot water, towel over head Respiratory congestion Eyes closed; not for children under 7
Topical Application Dilute in carrier oil, massage into skin Localised therapeutic effect, skin care Always patch test; follow dilution guidelines
Bath 5–10 drops in bath dispersant, add to warm bath Full body relaxation Never add undiluted oils to bath water
Compress 4–5 drops in warm/cold water, soak cloth, apply Localised pain, inflammation Test temperature before applying
Roller Bottle Dilute in 10ml carrier, apply to pulse points Convenient daily use Follow dilution guidelines; label clearly

Essential Oils in Ayurveda — The Classical Connection

Plant Sanskrit Name Ayurvedic Use Modern Essential Oil Use
Sandalwood (Santalum album) Chandana Pitta-reducing, skin care, meditation Skin care, meditation, grounding
Vetiver (Vetiveria zizanioides) Ushira Cooling, Pitta-reducing, skin care Grounding, cooling, skin care
Turmeric (Curcuma longa) Haridra Anti-inflammatory, skin care Anti-inflammatory, skin brightening
Ginger (Zingiber officinale) Shunthi / Ardraka Digestive, warming, Vata-reducing Warming, digestive, circulation
Black Pepper (Piper nigrum) Maricha Digestive, warming, Kapha-reducing Warming, circulation, digestive
Cardamom (Elettaria cardamomum) Ela Digestive, aromatic, Tridoshic Digestive, uplifting, warming
Camphor (Cinnamomum camphora) Karpura Cooling, respiratory, ritual purification Respiratory, cooling, analgesic
Frankincense (Boswellia serrata) Shallaki Anti-inflammatory, joint care, meditation Skin rejuvenation, meditation, anti-inflammatory

Essential Oils for Skin — By Skin Type

Skin Type Recommended Oils Carrier Oil Dilution
Dry skin Rose Otto, Sandalwood, Frankincense, Geranium Rosehip, Sweet Almond, Avocado 1–2%
Oily / acne-prone Tea Tree, Lavender, Geranium, Bergamot FCF Jojoba, Grapeseed 1%
Sensitive skin Lavender, Chamomile, Neroli, Rose Otto Jojoba, Sweet Almond 0.5–1%
Mature skin Frankincense, Neroli, Rose Otto, Patchouli Rosehip, Argan, Marula 1–2%
Hyperpigmented Turmeric CO2, Frankincense, Lemon (FCF) Rosehip, Sea Buckthorn 0.5–1%

Kerala's classical medicated skin oils — Nalpamaradi Keram (skin brightening), Kumkumaadi Tailam (luxury facial), Eladi Keram (sensitive skin), Pinda Tailam (cooling) — are not essential oil blends but classical Ayurvedic formulations processed in coconut or sesame oil.

Essential Oils for Hair

Hair Concern Recommended Oils Carrier Oil Application
Hair growth Rosemary, Cedarwood, Peppermint, Ylang Ylang Castor, Coconut, Jojoba Scalp massage, leave 30–60 min
Dandruff Tea Tree, Lavender, Cedarwood, Patchouli Coconut, Jojoba Scalp massage, leave 30 min
Dry / damaged hair Sandalwood, Geranium, Ylang Ylang Coconut, Argan, Sweet Almond Mid-lengths to ends, leave 1 hour
Oily scalp Lemon, Rosemary, Geranium, Tea Tree Jojoba (light) Scalp only, leave 20 min
Premature greying Rosemary, Amla (infused), Bhringraj (infused) Coconut, Sesame Scalp massage, leave overnight

Blueberry Botanicals — Our Essential Oil Sourcing Standards

Standard Our Commitment
Botanical traceability Full botanical name, country of origin, and plant part on every product
Extraction method Clearly stated on every product — no ambiguity
Batch coding Every batch carries a unique code for full traceability
GC/MS testing Available on request for all essential oils
No adulteration No synthetic fragrance addition, no undisclosed dilution
Kerala sourcing priority Kerala-origin oils (vetiver, cardamom, lemongrass, ginger) sourced directly from Kerala
Dark glass packaging All oils supplied in amber glass to prevent UV degradation

Frequently Asked Questions — Essential Oils

What is the difference between an essential oil and a fragrance oil?

Essential oils are 100% natural plant extracts obtained through distillation or cold pressing. Fragrance oils are synthetic or semi-synthetic aromatic compounds with no therapeutic value. Always verify you are purchasing a genuine essential oil.

Can essential oils be ingested?

Internal use requires professional training. We do not recommend internal use without guidance from a qualified clinical aromatherapist. Many oils safe for topical or aromatic use are toxic when ingested.

What is the shelf life of essential oils?

Most essential oils last 1–3 years when stored correctly. Citrus oils oxidise faster (6–12 months). Base note oils like sandalwood, vetiver, and patchouli improve with age and can last 5+ years.

What is the difference between Indian and Australian sandalwood?

Indian sandalwood (Santalum album) is the classical Ayurvedic standard, considered superior in therapeutic quality. Australian sandalwood (Santalum spicatum) is a more sustainable alternative with a slightly different chemical profile.

Why is rose essential oil so expensive?

It takes approximately 3–5 tonnes of rose petals to produce 1 kilogram of rose otto. Flowers must be hand-harvested at dawn. This extreme labour intensity makes rose otto one of the world's most expensive essential oils.

What is the difference between lavender and lavandin?

True lavender (Lavandula angustifolia) grows at high altitude with superior therapeutic properties. Lavandin (Lavandula x intermedia) is a hybrid with higher camphor content and lower cost. Always check the botanical name.

How do I store essential oils correctly?

Store in amber or cobalt blue glass, tightly capped, in a cool dark place. Do not store in plastic — essential oils dissolve plastic. Keep away from children and open flames.

What is a hydrosol?

A hydrosol (floral water or hydrolat) is the aromatic water produced as a by-product of steam distillation. Much gentler than essential oils, hydrosols can be used directly on skin without dilution. Rose water and vetiver water are classic Kerala beauty examples.

Are essential oils safe for children?

Avoid all essential oils for infants under 3 months. Use only lavender and chamomile (0.5% dilution) for children under 2. Avoid eucalyptus, peppermint, and camphor near children under 10.

What is the difference between CO2 extraction and steam distillation?

CO2 extraction uses supercritical carbon dioxide at low temperatures, producing a more complete extraction. Steam distillation uses heat, which can degrade some heat-sensitive compounds. CO2 extracts are generally superior in quality but more expensive.

Related Resources from Blueberry Botanicals

Regulatory Compliance

This content and all related products comply with:

  • Drugs and Magic Remedies (Objectionable Advertisements) Act, 1954 (India)
  • Advertising Standards Council of India (ASCI) Guidelines
  • Food Safety and Standards Act, 2006 (FSSAI)
  • Consumer Protection Act, 2019 (India)
  • Google Global Healthcare & Medicines Policy
  • Ayurveda, Siddha and Unani Drugs (ASU) Regulations

Last Updated: June 2026 | Maintained by: Blueberry Botanicals Content Team | Classification: Public Knowledge Hub | Status: Active