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The full process of how to extract woad from fresh Isatis tinctoria leaves. Woad is a blue pigment that you can use in fiber dyeing & soap making.
Originating on the steppes of central Asia, woad, also known by its Latin name Isatis Tinctoria, has been cultivated throughout Europe and the Mediterranean for millennia. Though its seeds have been found in French Neolithic sites, the first evidence of it being used in the dyeing of cloth comes from ancient Egypt. Later evidence of woad dyes comes from Roman, Viking, and Medieval sources and sites.
If I ever meet anyone who isn’t familiar with this plant, I tend to refer them to Braveheart, which nearly everyone has seen. Once I mention Mel Gibson painting his face blue, it tends to flip a switch for people, though there’s some debate over whether the Britons ever used woad for this purpose. I use woad (and indigo!) in soapmaking and am curious as to how it’s extracted from leaves. This is how I extracted woad pigment from woad leaves I grew in the garden.
Green Leaves into Blue Dye
It’s hard to believe that these green leaves contain such a vivid blue pigment. I wonder how the first people actually discovered it. So many of our past discoveries seem purely accidental, so I don’t doubt it was the same with woad. However, there are quite a few steps in the extraction process, making me wonder how on earth someone could have stumbled upon it.
To extract woad, you must first infuse leaves in nearly boiling water – preferably soft water such as rainwater. After ten minutes, the leaves are removed and squeezed of any juice before being discarded on the compost pile. The resulting liquid is strained, and then soda ash is added, which starts the process of extraction. Soda ash, sodium carbonate, can be sourced from the ashes of various types of plants – it creates carbonic acid when mixed with water and is also commonly used as a water softener. Through a process of aeration, settling, rinsing, filtering, and drying, you’re left with a natural blue pigment that can be stored and used indefinitely.
Woad for Health and Skin
Recently I’ve come across a few people who have asked me about the use of woad in skincare and whether it is safe. My answer is that woad is a non-hazardous natural product that is safe to handle and use externally.
Woad is also taken internally, though I’ve never tried it myself. Used in both European and Chinese herbal medicine for at least two thousand years, compounds in woad are said to combat certain types of cancer and anti-inflammatory diseases. Human studies from China have also shown that woad has antimicrobial, antibacterial, antiviral, and antiparasitic qualities. 
Woad as a Dye and Colorant
There is also some misinformation on the internet on whether woad will stain your skin. I can imagine the deduction work in this assumption: Since woad is used to dye cloth, wouldn’t it also color anything else it comes into contact with? I want to assure you that woad, as a powdered pigment, colors only the soap. It works in much the same way as mineral pigments and suspends as tiny granules, only giving the illusion of dyeing the soap. To use woad as a dye, additional chemicals such as alum and spectralite are required to get it to ‘fix’ to the cloth or wool.
Another positive point of woad is that it breaks down much more easily and naturally than commercial oxides. This property makes this product a much more environmentally sensitive alternative to micas, oxides, and other laboratory-created soap coloring agents.
In short, woad is safe, won’t stain your skin, and is a lovely and authentic natural colorant for use in making handmade woad soap. I enjoy using it and growing it in my own garden and would encourage anyone else who is interested in woad to try it out as well.
 Isatis Tinctoria