Newsgroups: alt.folklore.herbs
Subject: Re: Woad
From: David Powner <David.filtermx.demon.co.uk>
Date: 6 Jun 1995 18:12:12 +0100

> I'd like to know what herbs go into making woad, specifically the celtic blue stuff.

Woad is a biennial/perennial weed - Isatis tinctoria. No longer cultivated as a colouring, and occasionally found in cornfields.

The blue dye is obtained by crushing the leaves and leaving them exposed to the air.

From: 70571.2205.compuserve.com (Rowan Winters)

I have been growing and processing woad for many years now and I have an article that I will re-post separately here. A few basic points about woad:

  1. It is easy to grow, so easy that I believe some states restrict it due to its aggressively self-seeding nature.
  2. You can process the 'indigotin' (the blue dye chemical itself) out of woad fairly easily. Most plants, including the more difficult to grow indigo, have much more indigotin in them than woad, so plant lots of woad if you have the room.
  3. Once you have the indigotin, you can dye with it just as if it came from true indigo itself. But that is a special kind of dyeing called 'vat-dyeing' and a WHOLE other story in itself. Good luck!

Subject: How To Process Woad Dye
From: 70571.2205.compuserve.com (Rowan Winters)

Processing Woad

This article is for those who have grown their own woad plants and want to process the blue dye from them. A bit of vocabulary first: "indigotin" is the blue dye, whether you get it from woad (Isatis tinctoria), true indigo (Indigofera tinctoria), or some other source. To process fresh woad into blue dye, you will need fresh woad plants, sparkling non-sudsy ammonia, an egg-beater, cooking whip, or electric mixer; some glass jars and a non-stick cooking pan. Be prepared for a small yield because woad contains only one tenth of the indigo that true indigo plants contain. I have had trouble growing indigo, but here in Michigan I can grow all the woad I want. Woad spreads so aggresively that some states have laws prohibiting it, check first.

Cut woad plants, including leaves, stems and all above ground parts of the plants and chop or food process into small parts. Pack in glass jar until full and add boiling water, put on lid, and let steep for 1 hour. Strain all herb matter out and save liquid.

Next, first make the solution alkaline by adding ammonia and then the liquid must be oxidized by by beating air into it. Be sure to use non-sudsy, sparkling ammonia, as the regular sudsy type will produce large amounts of unwanted foam when air is worked into it. An egg-beater can be employed effectively, but an electric mixer is my choice.

Put the woad liquid into a mixing bowl and add enough ammonia to give a pH reading of 9 or more on litmus paper. Most litmus paper will not read as high as that, but adding extra ammonia will not hurt. Turn on mixer to "whip" or medium to high speeds, making sure that the beaters are not completely immersed in the liquid: the goal is not to mix the solution, but to get air and oxygen into it. Keep working the solution for 10-15 minutes and watch as it darkens and some blue particles begin to appear on the top.

The now oxidized liquid has indigo-blue in it ready to settle out and purify. Put the liquid into tall, narrow jars and watch the darker indigo settle out over an hour or more. When there is obvious sediment on the bottom, carefully pour off the clearer solution while keeping the dark sediment intact. Add water to the sediment and let the indigo settle out again. Repeat these steps until you have a clear liquid with blue sediment on the bottom.

You now have fairly pure indigo and water and are ready to evaporate the water off and powder up the indigo for storage. Pour off the water and pour the remaining water and indigo into a Silverstone or Teflon pan and let the water evaporate. When I tried other surfaces to dry out the indigo, the indigo stuck to it and had to be chipped off so I turned to more high-tech non-stick surfaces with great success. Indigo dried on Silverstone tends to peel up from the pan and can be easily removed, powdered and stored in a jar for further use.

Woad paint for canvas or bodies can be made by mixing the powdered woad with olive oil, gelatin and water, or other thickened, non-toxic bases. To dye textiles, try normal indigo vat-dyeing.

Good luck!

Books to check out:

  • Buchanan, Rita, A WEAVER'S GARDEN, 1987; Interweave Press, 306 North Washington Ave, Loveland, Colorado 80537. ISBN 0-934026-28-9.
  • Androsko, Rita, NATURAL DYE AND HOME DYEING, Dover Publications, ISBN 0-486-22688-3

Seed Suppliers:

  • The Sandy Mush Herb Nursery, Rt. 2 Surret Cove Road, Leichester, North Carolina 28748-9622
  • Mr. and Mrs. Hyde (Well-Sweep), 317 Mt. Bethel Road, Port Murray, NJ 07865 Phone 201-852-5390