Making Herbal Infused Oils: Your Complete Beginner’s Guide

Make healing herbal oils for salves, massage, and skin care. Learn oil selection, fresh versus dried herbs, solar versus heat infusion, proper ratios, and shelf life. Simple methods create effective topical preparations at home. The foundation for balms, salves, massage oils. Simple (herbs + oil + time), cost-effective (DIY vs. $20-40 commercial), customisable.

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What This Guide Will Teach You

Infused herbal oils are the foundation of so many remedies—they’re what you use to make balms, salves, massage oils, and countless other skin preparations. But they’re also incredibly simple to make: just herbs and oil, time and patience.

This guide will show you how to capture the healing compounds from plants into a bottle of oil, transforming ordinary olive oil into powerful medicine. You’ll learn why this method works, which herbs are best suited to oil infusions, and how to avoid the common mistakes that can ruin a batch. By the end, you’ll be confidently making your own infused oils that rival anything you can buy in stores.

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What Exactly Is an Infused Oil?

An infused herbal oil (sometimes called a macerated oil) is simply plant material steeped in carrier oil for weeks to months, allowing the oil to extract and hold the plant’s fat-soluble medicinal compounds.

It’s important to understand what infused oils are NOT: they’re not essential oils. Essential oils are highly concentrated aromatic compounds extracted through steam distillation or cold pressing. Infused oils are much gentler—you’re basically making herbal “tea” using oil instead of water as your solvent.

Why This Matters

Your skin loves oil. It’s designed to absorb lipid-soluble (fat-loving) compounds, and many of the most therapeutic plant chemicals fall into this category. When you infuse herbs in oil, you’re extracting:

• Essential oil components: The aromatic compounds that provide antimicrobial and anti-inflammatory effects
• Resins: Sticky plant compounds excellent for wound healing and protecting skin
• Carotenoids: Pigments like those in calendula that support skin regeneration and provide antioxidant protection
• Fat-soluble vitamins: Including vitamin E and provitamin A
• Phytosterols: Plant compounds that support skin barrier function

These compounds simply won’t extract into water-based preparations like teas. Oil is the key that unlocks them.

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The Science Behind How Infused Oils Work

Understanding what’s happening at a chemical level helps you make better oils.

Why Oil Extracts Different Compounds Than Water

Remember learning in school that “oil and water don’t mix”? This is because of polarity—a fundamental chemistry concept.

Water is polar (it has positive and negative ends to its molecules), which means it dissolves other polar substances like sugars, minerals, and many plant acids.

Oils are non-polar (their molecules are evenly balanced), which means they dissolve other non-polar substances—things like resins, essential oil components, and fat-soluble vitamins.

This is why you need both water-based preparations (teas, tinctures) and oil-based preparations (infused oils) in your herbal toolkit—they extract completely different sets of compounds from the same plant.

The Role of Time and Heat

Oil is thick (viscous). When you place dried herbs in oil, the medicinal compounds need to slowly diffuse (move) from inside the plant cells out into the surrounding oil. This takes time because oil molecules move much more slowly than water molecules.

Heat speeds this process up. Warm oil has lower viscosity (it’s thinner and flows more easily), and heat increases the kinetic energy (motion) of molecules, helping them diffuse faster. This is why placing your jar in a sunny window or using gentle heat can create a more potent extraction.

But there’s a trade-off: too much heat degrades delicate compounds. Gentle warmth extracts effectively while preserving therapeutic properties.

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The Critical Safety Issue: Why Herbs MUST Be Dry

This is probably the single most important safety rule for making infused oils: you must use completely dried herbs.

Here’s why: water and oil create a perfect storm for dangerous bacterial growth. Clostridium botulinum—the bacteria that produces botulinum toxin—is anaerobic (thrives without oxygen) and can grow in the water droplets at the bottom of an oil jar. The oil creates an oxygen-free environment, and any water present from fresh herbs provides the medium for bacterial growth.

Botulism is potentially fatal. This isn’t a guideline; it’s an absolute safety requirement. Your herbs must be crisp-dry, crumbling easily when you handle them.

Why this matters in your daily life:

You might think “my herbs look dry enough”—but if they bend instead of snap, they still contain enough moisture to create botulism risk. This bacteria produces one of the most potent toxins known, and symptoms can appear days or even weeks after exposure. It’s not worth the risk. Always wait for that satisfying snap when you test your herbs.

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When to Use Infused Oils (And When Not To)

Perfect For:

• Skin healing: Calendula, plantain, comfrey, and St. John’s wort all contain fat-soluble compounds that promote wound healing, reduce inflammation, and support tissue repair
• Muscle and joint pain: Arnica, ginger, and warming herbs infused in oil provide targeted relief when massaged into sore areas
• Aromatherapy and relaxation: Lavender, chamomile, and rose create beautifully scented oils perfect for massage or adding to baths
• Base for other preparations: Once you have infused oil, you’re halfway to making balms, salves, lotions, and other skin products
• Dry skin and general skin health: Nourishing herbs like calendula or rose combined with good carrier oils provide excellent all-over skin support

Not Ideal For:

• Water-soluble compounds: If you want the minerals from nettle or the mucilage from marshmallow, you need water-based preparations. Oil won’t extract these
• Internal use: While some herbal oils can be used in cooking, medicinal infused oils are typically for external use only. For internal herbal remedies, use teas or tinctures
• Quick needs: Infused oils take 4-6 weeks minimum. If you need medicine today, this isn’t your method
• Fresh plant material (with rare exceptions): The moisture content creates serious safety risks

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Your First Infused Oil: The Basic Solar Method

Let’s walk through making your first batch using the simplest, safest method.

What You Need

Ingredients:

• Dried herbs of your choice (enough to fill jar 1/2 to 2/3 full)
• Carrier oil (olive oil is excellent for beginners)
• Optional: Vitamin E oil (acts as a preservative)

Equipment:

• Clean, dry glass jar with tight-fitting lid (litre size works well)
• Cheesecloth or muslin for straining
• Dark glass bottles for storage (amber or cobalt blue)
• Labels
• Sunny windowsill or warm spot

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The Step-by-Step Process

Step 1: Ensure herbs are completely dry

Take a piece of your herb and try to bend it. Does it snap cleanly? Crumble easily? That’s dry enough. Does it bend? Still has any flexibility? It needs more drying time.

You can dry herbs by:

• Hanging in bunches in a warm, dry location
• Spreading on screens or racks
• Using a dehydrator on lowest setting
• Oven on lowest temperature with door cracked open

Why this matters: This step is non-negotiable for safety. Any water content creates botulism risk.

Step 2: Choose and prepare your carrier oil

For beginners, extra virgin olive oil is the best choice:

• Readily available and affordable ($8-12/litre in NZ)
• Very stable (resists rancidity well)
• Contains its own antioxidants
• Proven track record of thousands of years of use

Other good options:

• Sunflower oil: Lighter, less scent, high in vitamin E ($6-10/litre)
• Sweet almond oil: Pleasant, mild, good for facial oils ($15-25/250ml)
• Jojoba oil: Technically a liquid wax, very stable but pricier ($20-35/100ml)

Avoid: coconut oil (solid at room temperature), strongly scented oils, heavily refined oils.

Step 3: Fill your jar with herbs

Place your dried herbs in the jar, filling it 1/2 to 2/3 full. Don’t pack them down tightly—you want the oil to circulate.

Lightly chopping or crumbling larger pieces increases surface area, which improves extraction.

Why this ratio: Too many herbs and you won’t have enough oil to cover them. Too few herbs and your oil will be weak. This ratio provides optimal extraction.

Step 4: Cover completely with oil

Pour oil over the herbs, making absolutely sure they’re completely submerged. Add at least 2-5cm of extra oil above the herb line.

Use a chopstick or clean spoon to stir and release any air bubbles trapped in the herbs.

Why this matters: Any herbs exposed to air will oxidise, potentially grow mould, and spoil your batch. Complete coverage is essential.

Step 5: Seal and label

Put the lid on tightly. Label with:

• Herb name
• Oil type
• Date started
• Method (solar infusion)

Why labelling matters: After a few weeks, all oils look similar. You’ll forget what’s what without labels.

Step 6: Place in sunny location

Find a spot that gets direct sunlight for at least a few hours daily—a north-facing windowsill is perfect in the Southern Hemisphere.

The gentle, cycling warmth of sun during the day and cooling at night creates an ideal extraction environment.

Step 7: Shake daily

Once a day (or whenever you remember), give the jar a good shake. This:

• Redistributes the herbs
• Moves fresh oil into contact with plant material
• Prevents herbs from settling and compacting
• Helps release trapped air

Step 8: Infuse for 4-6 weeks

This is the hard part—waiting! The solar method requires patience. Mark your calendar for 4 weeks minimum, 6 weeks for maximum potency.

During this time, check occasionally for:

• Herb colour changes (often fade as compounds move into oil)
• Oil colour changes (should deepen as it extracts compounds)
• Any signs of problems (mould, off smells, cloudiness)

Why so long: Oil is viscous. Molecular diffusion in this thick medium simply takes time. Rushing produces weak oil.

Step 9: Strain thoroughly

Step 9: Strain thoroughly

After 4-6 weeks, it’s time to separate the oil from the spent herbs.

Line a strainer with several layers of cheesecloth or muslin. Pour the oil and herbs through, letting it drip naturally. Then gather up the cloth and squeeze firmly to extract every last drop of oil—you’d be surprised how much the herbs absorb.

Some people do a second straining through fresh cloth to remove any tiny particles.

Pro tip: Do this over a bowl or pot, not directly into storage bottles. It’s messy, and you’ll want to assess the oil before bottling.

Step 10: Add vitamin E (optional) and bottle

If using vitamin E as a preservative, add now: about 1/4 teaspoon (approximately 1.25ml) per 250ml of oil. Mix well.

Pour into dark glass bottles using a funnel. Fill bottles nearly full (minimal air space), cap tightly, and label with:

• Herb name
• Oil type
• Date bottled
• “For external use”

Step 11: Store properly

Store your finished infused oil:

• In a cool, dark location (cupboard away from stove)
• Away from direct sunlight
• At stable temperature (avoid places with big temperature swings)

Properly made and stored oil should last 12-18 months.

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Understanding Different Infusion Methods

The solar method is gentlest and safest for beginners, but other methods exist.

The Heat Method (Faster Alternative)

For when you need oil more quickly or live somewhere without reliable sun:

Equipment: Double boiler, slow cooker, or improvised double boiler (heat-safe bowl over pot of water)

Process:

1. Place dried herbs and oil in double boiler
2. Heat on lowest setting (aim for 40-50°C, should feel warm but not hot to touch)
3. Maintain this gentle warmth for 2-8 hours
4. Stir occasionally
5. Strain immediately while warm

Advantages: Creates potent oil in hours instead of weeks. Better for tough plant materials like roots and bark.

Disadvantages: Risk of overheating and degrading compounds. Requires monitoring. Uses energy.

Best for: Roots (burdock, dandelion), barks, tough leaves (kawakawa), and situations where you need oil quickly.

The Room Temperature (Folk) Method

Simply herbs and oil in a jar in a cupboard for 6-8 weeks. No heat, just time.

Advantages: Zero risk of heat damage, very gentle, requires no special conditions.

Disadvantages: Slowest method, potentially weakest extraction.

Best for: Extremely delicate flowers, situations where you can’t provide warmth, or when you’re in no hurry.

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Your First Project: Calendula Healing Oil

Let’s make something practical that you’ll use constantly.

Why Calendula?

Calendula (Calendula officinalis) is THE premier skin-healing herb:

• Wound healing: Speeds closure of cuts and scrapes
• Anti-inflammatory: Reduces redness and swelling
• Antimicrobial: Helps prevent infection
• Gentle: Safe for all ages and sensitive skin

The bright orange flowers contain carotenoids, resins, and flavonoids—all highly oil-soluble and perfect for extraction.

What You Need

• Dried calendula flowers: $10-18/50g from health stores or bulk suppliers (or grow your own!)
• Olive oil: $8-12/litre from any supermarket
• Vitamin E capsules: Optional, $10-15 for bottle at pharmacy (poke with pin and squeeze out oil)
• Large jar and supplies as listed above

The Process

1. Fill jar 2/3 full with dried calendula flowers (about 50-75g for a 1-litre jar)
2. Cover with olive oil plus 5cm extra
3. Release air bubbles, seal, label
4. Place in sunny spot for 6 weeks
5. Shake daily
6. Strain, add vitamin E if desired, bottle

Cost Breakdown

• Calendula flowers: $10-18 (or free if home-grown)
• Olive oil: $8-12
• Vitamin E: $1-2 worth from capsules
• Jar: reuse or $2-5

Total: $20-40 for 750-900ml of finished oil

Compare to commercial calendula oil at $25-40 for 100ml, and you’re getting 7-9 times more oil for the same price or less.

What to Use It For

• Minor cuts, scrapes, and skin tears
• Dry, cracked skin on hands and feet
• Nappy rash and baby skin irritation
• General skin moisturising
• Base for healing balms and salves
• Massage oil for sore muscles

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Where to Source Your Materials in New Zealand

Dried Herbs

Growing Your Own

This is the most economical long-term option. Many medicinal herbs grow beautifully in New Zealand gardens:

• Calendula: Easy annual, self-seeds readily. Sow in NZ autumn (March-April) or spring (September-October). $6-8 for seed packet
• Lavender: Perennial shrub, plant in spring (September-November) for best establishment. $8-15 per plant, lasts for years
• Rosemary: Woody perennial, nearly indestructible. $8-15 per plant
• Plantain: Probably already in your lawn (just identify correctly!)

Growing success varies by NZ climate zone—subtropical North vs temperate/cool South. Check local garden centres for advice on your specific region.

Buying Dried Herbs

Physical stores:

• Bin Inn: Good bulk herb selection, reasonable prices
• Health food stores: Smaller quantities, higher prices but good quality
• Herbal supply stores: Best quality, wider selection, moderate prices

Specific NZ Online Suppliers:

• Cottage Hill Herbs (cottagehillherbs.co.nz)
• Herbalshop NZ (herbalshop.co.nz)
• Go Native NZ (gonative.co.nz)
• Lotus Oils NZ (lotusoils.co.nz)
• Commonsense Organics (Wellington, Auckland): Physical stores with bulk herbs

Prices: Expect $8-20 per 50g for flowers/leaves, $12-25 per 50g for roots/barks.

Quality check—good dried herbs should:

• Retain strong colour (fading indicates age)
• Have strong aroma (if aromatic herbs)
• Be crisp-dry but not dusty
• Come from suppliers with high turnover

Wild Foraging in NZ

With proper identification, permission, and sustainable practices:

• Plantain (Plantago major/lanceolata): Common in lawns and waste areas throughout NZ
• Dandelion (Taraxacum officinale): Naturalised everywhere
• Chickweed (Stellaria media): Cool-season weed, common in gardens

Important NZ foraging considerations:

• Avoid sprayed areas: Parks, roadsides, and council land are often treated with herbicides
• DOC land: Check regulations before harvesting. Some plants are protected
• Private property: Always get permission from landowners
• Sustainable harvesting: Take no more than 10% of any plant population
• 100% identification certainty required: Mistakes can be dangerous. Use multiple field guides or consult with experienced foragers
• Native plants: Leave wild populations undisturbed. If you want to use native species, grow your own

Carrier Oils

Olive oil: Every supermarket, $8-15/litre. Look for:

• Extra virgin (less refined = more antioxidants)
• Cold-pressed (gentle processing)
• In dark glass or tin (protects from light)

Specialty oils (sunflower, almond, jojoba):

• Health food stores
• Lotus Oils NZ (lotusoils.co.nz)
• Online suppliers
• Specialty food stores

Budget tip: For learning, start with supermarket olive oil. Once you’re confident, invest in specialty oils for specific projects.

Supplies

Jars

• Save pasta sauce and pickle jars (free!)
• Kmart, The Warehouse: $2-5 each
• Packaging suppliers: Buy in bulk

Dark Glass Bottles

• Online packaging suppliers: $2-5 each for 100-250ml bottles with droppers
• Health food stores: Sometimes sell empties
• Reuse supplement or essential oil bottles (thoroughly cleaned)

Cheesecloth/Muslin

• Spotlight, Lincraft: $5-12/metre
• Fabric stores
• Online suppliers
• Alternative: Clean old t-shirt or tea towel works perfectly

Essential Equipment (Start Here):

• Glass jar with lid (reuse or $2-5)
• Straining cloth (old t-shirt or $5-12/metre muslin)
• Storage bottles (reuse or $2-5 each)

Nice to Have:

• Dark glass bottles with droppers (easier to use)
• Cheesecloth (easier than t-shirt for straining)
• Multiple jar sizes for different batches

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Specific Herbs That Excel in Oil Infusions

Let’s explore herbs particularly well-suited to oil extraction.

For Skin Healing

Calendula (Calendula officinalis)

Already covered above. The gold standard for skin-healing oils.

Plantain (Plantago major/lanceolata)

That “weed” in your lawn is medicine! Contains allantoin (promotes cell growth), aucubin (antimicrobial), and tannins (astringent). Excellent for:

• Bug bites and stings (reduces itching and swelling)
• Minor wounds
• Skin irritations
• Drawing action for splinters

Comfrey (Symphytum officinale)

Contains allantoin in high concentrations. Speeds healing of:

• Bruises and sprains
• Closed fractures (the traditional “bone knit”)
• Minor burns

St. John’s Wort (Hypericum perforatum)

Fresh flowers traditionally used (one of the rare exceptions to dry-only rule). Creates deep red oil rich in hypericin. Excellent for:

• Nerve pain (topical for neuropathy, sciatica)
• Burns (after initial cooling)
• Bruises and inflammation

For Muscle and Joint Pain

Arnica (Arnica montana)

Contains helenalin (anti-inflammatory). THE remedy for:

• Bruises and contusions
• Sore muscles
• Arthritis and joint pain

Ginger (Zingiber officinale)

Warming, increases circulation. Ground dried root infused in oil helps:

• Muscle aches
• Arthritis
• Poor circulation
• Warming massage oils

For Aromatherapy and Relaxation

Lavender (Lavandula angustifolia)

Solar method only (heat destroys delicate scent). Creates wonderfully aromatic oil for:

• Relaxation massage
• Headache relief
• Minor burns
• Sleep support (massage into feet before bed)

Chamomile (Matricaria chamomilla)

Gentle, calming. Excellent for:

• Baby massage oils
• Sensitive skin
• Stress relief
• Inflammation

Rose (Rosa spp.)

Luxurious and therapeutic. Petals create beautiful oil for:

• Facial skin care
• Emotional support
• Dry, mature skin
• Special occasion gifts

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Troubleshooting Common Issues

Problem: Cloudy oil

Cause: Water contamination from insufficiently dried herbs.

Solution: If caught early (within first few days), you might salvage by straining out herbs and starting over with completely dry herbs. If it’s been longer or you see mould, discard for safety.

Prevention: Ensure herbs are crisp-dry. When in doubt, dry longer.

Problem: Mould on surface

Cause: Herbs exposed to air, or water contamination.

Solution: Discard immediately. Mould can produce toxins that permeate the oil.

Prevention: Keep herbs completely submerged. Use dry herbs. Check regularly during infusion.

Problem: Rancid smell

Cause: Oil has oxidised.

Solution: Discard and start over.

Prevention:

• Add vitamin E as antioxidant
• Store in cool, dark location
• Use fresh oil (check expiration dates)
• Don’t overheat during extraction

Problem: Weak oil (doesn’t smell like herbs)

Cause: Not enough herbs, not enough time, or herbs were old/low quality.

Solution: Try the double infusion method—strain out spent herbs and add fresh dried herbs to the already-infused oil. Infuse another 4-6 weeks.

Prevention:

• Use correct herb-to-oil ratio (jar 1/2 to 2/3 full)
• Infuse for full 4-6 weeks minimum
• Use fresh, aromatic herbs from reliable sources
• Solar method in good sun

Problem: Oil won’t strain (too thick with plant material)

Cause: Mucilaginous herbs or too much plant material.

Solution: Warm gently (place jar in bowl of hot water for 10 minutes), which reduces viscosity. Or add small amount of fresh oil to thin.

Prevention: Don’t overfill jar with herbs. Some herbs (marshmallow, comfrey) are naturally gooey—this is normal.

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Safety Considerations

Botulism risk: Cannot be overstated. Use only completely dry herbs. This is not negotiable.

Photosensitivity: St. John’s wort oil causes increased sun sensitivity. Don’t use on skin that will be exposed to sun for 24-48 hours after application.

Essential oil allergies: Some people are allergic to plant essential oils. Always patch test new oils on small area of skin before widespread use.

Pregnancy and nursing: Most topical oils are safe, but avoid therapeutic doses of certain herbs:

• Pennyroyal (toxic)
• Rue (can cause uterine contractions)
• When in doubt, check with midwife or herbalist

Arnica safety: External use only, never on broken skin, never internal. Can cause contact dermatitis in sensitive individuals.

Comfrey safety: Don’t use on deep open wounds (can cause surface healing over infected tissue underneath). Avoid during pregnancy.

Storage and shelf life:

• Properly made oils last 12-18 months with vitamin E
• 6-12 months without
• Store cool, dark, airtight
• Discard if rancid smell develops

For chronic skin conditions: Work with a dermatologist or healthcare provider alongside herbal support. Infused oils complement but don’t replace professional medical care.

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Building Your Infused Oil Practice

Start simple. Make one oil using one herb you know is safe and effective. Use it. Notice how it works, how it feels, how the herbs extract, how long it lasts.

Then expand. Try different herbs. Experiment with different extraction methods. Create custom blends. Make enough to last the year.

As you gain experience, you’ll develop instincts about:

• Which herbs are dry enough
• Optimal herb-to-oil ratios for different plants
• How long to infuse for maximum potency
• Which carrier oils work best for different purposes

Infused oils are foundational in herbal practice. Once you master them, a whole world of remedies opens up—balms, salves, lotions, creams, lip balms, massage oils, and more.

This is herbalism at its most practical: taking simple ingredients, applying time-tested methods, and creating powerful medicine that supports health and healing.

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Sources & Further Reading

Books:

• Green, J. (2000). The Herbal Medicine-Maker’s Handbook: A Home Manual. Crossing Press.
• Gladstar, R. (2012). Rosemary Gladstar’s Medicinal Herbs: A Beginner’s Guide. Storey Publishing.
• Tourles, S. (2007). The Herbal Body Book. Storey Publishing.

Scientific Literature:

• Carson, C. F., Hammer, K. A., & Riley, T. V. (2006). Melaleuca alternifolia (Tea Tree) Oil: a Review of Antimicrobial and Other Medicinal Properties. Clinical Microbiology Reviews, 19(1), 50-62. https://doi.org/10.1128/CMR.19.1.50-62.2006
• Preethi, K. C., & Kuttan, R. (2009). Wound healing activity of flower extract of Calendula officinalis. Journal of Ethnopharmacology, 125(2), 390-392. https://doi.org/10.1016/j.jep.2009.07.033

New Zealand Resources:

• Local herb suppliers and nurseries
• Community gardens for growing medicinal herbs
• DOC guidelines for foraging on public land

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