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Join Jo: How to Make Infusions for Use in Soapmaking (& Cosmetics!)

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hanging herbs and plants

Did you miss the first post in the Coloring Soap Naturally series? You can find it here!

Are you ready for the next step on our plant colorant journey? I am so excited to teach you how to make infusions and see the results you achieve. Please share them with the rest of us in the comments section below!

Before we begin a quick word on cleanliness!

Regardless of what equipment or method of infusion you use, please ensure you use clean jars (recycled jars are great just make sure they are clean), clean utensils and clean hands.  Make sure you have an accurate set of scales to 1oz and now let the fun begin!

How to Make Infusions with Plant/Botanical Material

Infusing can be done by two methods – cold or heat infusion.  Cold infusion is my favorite, however, it’s up to you which way you prefer to infuse, and how quickly you would like to use the infused colorant may be the deciding factor.

 A Collection of Jo's Plant Infusions

Each infusion I make (cold or heat) starts out with 1 ounce of powdered plant colorant, or if I am using whole flowers or petals, one full jar (make a note of the weight before you add the oil). I record the weight of the whole flowers or petals so when I want to repeat the color, I know how I achieved it in the first place.

I never use fresh herbs for any of my infusions, although some people do with great success. I did try it once, and the smell and mold have definitely ensured I will never do that again!

If you don’t think you need this much infusion you can halve the above amounts, but I would encourage you to make the full jar. The infusion really does last quite a while, and you will have used it all long before the shelf life of the oil runs out.

How to Make Cold Infusions

This method is believed to be less harsh on the plants. I use it for both the healing properties (salves/balms) and the colorants that plants give.

Measure 1 ounce of powdered plant colorant, add to your jar, and fill the jar to the top with your chosen oil. Screw the lid on. If you are using whole flowers or petals, fill those to the top of the empty jar, cover them completely with your chosen oil and screw the lid on. You will need to stir and/or shake the jar to ensure all the colorant is mixed in.

Once the oil and the plant matter are mixed in the jar, I leave them on my kitchen bench, (or somewhere that I always see them – near the coffee or tea in my kitchen), for 7 days. Each day I turn and shake the jar twice a day, to ensure all the colorant touches the oil. After 7 days I move the jar to a shelf (low light area) and turn and shake the jar once a week for 6 weeks.

Over that time you will see the infusion start to change color. Some are quite instant (alkanet) and others will not even look like they have changed at all.  Yellowdock in particular, gives a gorgeous strawberry pink in soap, yet will hardly change color in its infusion.

 Beautiful Annatto (Bixa Orelana) Seed Infusion

Cold infusion takes about 6 – 8 weeks (I like mine to be 8+ weeks) before reaching a beautiful color. Not everyone chooses to place their infusion in a low light area, some prefer to leave their colorant on their kitchen window and allow some sun (heat) to enter the jar.

I don’t do this because once I make the soap, I try to avoid light to prevent oxidation of the plant matter that leads to the color fading. It makes more sense to me (and this is completely personal choice) to keep light away from the infusion and the soap to give the color the maximum chance of lasting.

However, what if you don’t have 6+ weeks and you are desperate to use a natural plant colorant that you just found at the local shop, or just arrived in a box of goodies in the mail? Heat infusion will be your best friend.

How to Make Heat Infusions

I use the same amounts of powdered colorant or whole flowers/petals as I do for cold infusion.

Some people use a heat sealable tea bag and place their powdered plant matter in the bag and then into the oil. The bag is used so they don’t have to strain the powder out of the oil at the end of the infusion. I use cheesecloth if I need to strain (you can use a coffee filter – takes forever!!!).

I have found  that the powder settles to the bottom of the jar, and I can pour the colored oil straight off the top without having to strain.

 An infusion with powdered botanicals that sunk to the bottom

I like to use an old crockpot for my heat infusion method.  You can also use a large pot on the stove.

Once you have your power or whole flowers in the jar with the oil and the lid screwed on, place the jar into either the crockpot or the pan on the stove that you are going to use.  Fill the crockpot or pan as high as you can with water and turn the heat on low or set the crockpot to low.

 A set of infusions getting the crock pot treatment

Heat infusion takes 2 - 6 hours in the crockpot (low heat), or on the stove in a pan of water (again, low heat!) and the infused colorant can be used as soon as it is cool.  I usually apply heat for 3 hours if I use this method, and I leave the jar until completely cooled in the water.

If you're like me, you like to infuse different colorants at the same time, do yourself a favor and label the top of the jars.  I do have those mystery jars sitting here and the only way to know what is in them to use them.  I also date the jars and write the method of infusion on them. 

 Labeling the top of the jars is always a good idea!

Now you know how to infuse, next time I will show you how to use those infusions to achieve clear bright colors in your soapmaking. Are you ready?!


Did you miss the first post in the Coloring Soap Naturally series? You can find it here!

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