Macerating or infusing plant material in oil is a great way to capture the scent and/or medicinal qualities of a plant.
Infused oils can be made from many flowers and herbs, you can either grow your own, pick wild, or buy from a trusted supplier – the time of year and season is likely to play a part in your choice here. I always recommend using an organic, food grade source if you’re buying plant material, or be sure if you’re harvesting your own, that the plants have not been sprayed with chemicals. See some options for different plants to experiment with and suppliers are listed below.
An infused oil is quite different from an essential oil which is made by steam distillation or solvent extraction. These methods require a huge amount of plant material, specialist equipment and are usually very expensive. Maceration is a much more practical way to make small amounts of scented oil or oils with plant medicinal properties when you don’t have vast fields of land to grow on. It is also a ready to use product that does not need diluting before using on the skin as with an essential oil.
The process of maceration involves leaving plant material in a carrier oil (e.g. sunflower or almond oil) for a period of time until the oil takes on the scent or the quality of the plant. Have you ever had butter in your fridge, and an onion, and the butter ends up smelling of onion? The fat/oil naturally absorbs those fragrant molecules and others too.
Here are the instructions for making a maceration:
- Plant material – 100g fresh or 75g dried (e.g. flowers, herbs – see below for options)*
- Base Oil – 300g (eg. olive or sunflower oil). Choose something that has little or no scent if you want to capture the scent of a flower. I like apricot or jojoba for this and they already feel lovely on the skin. If you’re using a plant for its medicinal properties such as daisy or calendula, then the base oil doesn’t necessarily have to be without scent, you could use olive or sunflower oil. Also, something cheap and refined is fine, as you will be enriching it with the plant. For more details on base oils see: A List of Carrier Oils and Base Products, their Uses and Qualities.
- Container (Glass Jar with air tight lid).
- Muslin Cloth, or fine sieve.
- Option: Bain maire or double boiler (for the heated method outlined below).
The slow method: If you’re buying dried plant material then it’s ready to use. If you’re picking your own, make sure you do so when the flowers/leaves are dry and there hasn’t been any rain for a few days previously. You want to avoid any moisture getting into your mix at all costs, as this can contaminate it.
Once you’ve harvested your flowers/herbs lay them out to dry. Avoid putting them in the light or sun, you can purchase an ‘air dryer’ or lay them on a tray and keep in an ‘airing’ cupboard. An afternoon should be enough to lose the water in the petals, although I sometimes leave my air dryer out for days and the scent in my home is heavenly.
Collect the petals/leaves carefully and put them in the jar, you will naturally leave behind little bits of dust or grit as you pick them up, and there might be some you want to discard, any creepy crawlies should have crawled away by then.
Fill the jar to the top with the dry plant material, and then pour in the carrier oil. If you don’t have enough plants to fill the jar, use a smaller one, you want to just cover them with oil, and not leave any space for air. Check after a few hours to see if the jar needs topping up with oil, as the plants will start absorbing oil and may sink down into the jar, or any air trapped will have risen to the top and made space.
Seal the lid tightly and leave for 3-6 weeks in a warm cupboard, away from light or sunshine (airing cupboard is perfect), shake the jar every now and then, when you remember in case any more air bubbles form. I also label and date the jar, so I don’t forget what’s in it or when I need to strain it.
After at least 2 weeks, strain the spent plant material through some muslin cloth, or a very fine sieve, into a container (bowl, jug etc). You will notice the plant material has lost its colour and likely the oil has changed colour – depending on what plant you’re infusing. Squeeze as much oil as you can from the plant pulp and you are left with the enriched macerated oil. You may need to run the oil through the cloth twice to avoid any tiny bits of plants left in the oil, leaving them in could mean they start growing mould.
The fast method with heat: If you want to make your infused oil to use immediately, then you speed up the process by gently heating the flowers/herbs and oil. Instead of adding the dried plant material directly to a jar to keep, put them in a double boiler, bain marie or just a glass bowl that can fit over a pan – the aim is to let the steam from water in the bottom pan very gently heat the top pan or bowl (as if you were melting chocolate). Pour enough oil on so that all the plants are covered and saturated in oil and gently heat for 2-3 hours. Do not let the mixture heat too much, let the water in the bottom pan just about simmer. Do not leave the oil unattended as it is potentially flammable, but you will want to be around to enjoy the delicious aroma anyway and to ensure it doesn’t over heat. After the 2-3 hours is complete, remove from heat, allow to cool, and then strain through muslin cloth as with the above method.
For a more intense version you can repeat this whole process by adding more plant material to infuse the same oil with (for both methods).
The macerated oil is a useful ingredient for enriching the following products:
*Flowers & Herbs to try infusing, either for scent, medicinal qualities or both:
- Roses – if you want to capture the scent of roses in particular check out my blog on Rose Scented Oil – How To Make Your Own – with instructions specifically tailored to making rose infused oil.
- Calendula or Marigold petals, a great skin treat, that helps scars and skincare.
- Lavender flowers – a fresh scent with anti-microbial effects, soothes and calms skin.
- Chamomile flowers – calming soothing, helpful for eczema and sensitive skin.
- Daisy flowers – similar to arnica in action, so use for bumps and bruises, aches and pains.
- Rosemary leaves and stalks, invigorating, great for muscles aches and pains.
- Scented pelargonium leaves for the scent.
- Orange blossom for the scent and soothing properties.
- Violets – for the scent.
- Chickweed – very soothing and cooling for the skin, ideal for eczema and skin conditions.
- Self heal flowers – great for cuts and scrapes.
*Growing your own – if you want to grow your own plants to use for this, remember you need to avoid spraying chemicals like insecticides or fungicides to use them for making skin care products. If you’re buying new plants, make sure you use a reputable supplier, and that the Latin name of the plant is available as common names can be confusing or misleading. And by the way, I only have a balcony, and still manage to harvest enough plant material to keep me busy – calendula is super easy, as are pelargoniums (geraniums), rosemary, chamomile and thyme. Roses are a bit more effort but well worth it. It depends on your environment of course but there is a whole world of fun to be had, as well as providing some love for bees and other insects and wildlife!
- Wether you’re growing your own or picking from the wild, you must be 110% sure that the plant you’re using is what you think it is. Never guess! There are highly poisonous garden plants and wild plants out there that could result in serious injury and even death, so you want to be absolutely sure that what you’re infusing in oil is suitable to moisturise your skin with. A good rule to follow is if it’s edible, and you would use it in food or as a herbal tea, it will be fine to put on your skin – although some plants like chilli or garlic would not be appropriate for obvious reasons. Even if you buy plants to grow at home, check the ‘botanical’ name, garden centers are notorious for selling common name plants that might not be the same as the botanical species you intended. If you have any doubt, then don’t use it.
- Don’t use plants that have been sprayed with insecticides, or fungicides, as the oil will absorb these too.
- Make sure the plants you pick are clean, as you are not able to wash them, due to needing to avoid moisture, avoid picking plants from popular dog walking areas and pay attention to what you’re picking – you don’t want anything unintended sneaking in with your harvest.
- You could also try mixing different flowers for a blended fragrance or effect, although making separate infusions still leaves you open to blending at a later stage.
- You can use macerated oils on foods too, things like chilli, garlic, rosemary, thyme, even lemon peel in olive or sunflower oil and use it to drizzle on salads. You can just place the plant in the bottle of oil ready to use, as long as there is no water or moisture on it, it should keep for the duration of use.