Basic Alum Mordant Recipe for Dyeing Wool

Get the perfect color when dyeing wool fiber with this basic alum mordant recipe.

| December 2013

Home dyeing can be a gamble if you are new to the idea, but even if you are experienced in the art, knowing the reaction difference between animal fibers and plant based fibers can be crucial to proper dye absorption. Using The Handbook of Natural Plant Dyes (Timber Press, 2010) Sasha Duerr walks you through using mordants and natural dyes in perfect harmony. Use the recipe in this excerpt to learn how to dye wool fiber and create a basic alum mordant.

Basic Alum Mordant Recipe

You can prepare alum mordant for hot dyeing, cold dyeing, or solar dyeing. This recipe gives instructions for the hot-dyeing method. Weigh the fiber you are going to dye when it is dry, and then measure the alum in proportion to the fiber’s dry weight. Weigh the alum on a scale to get the proper amount. Before dyeing a natural fiber, soak it in water for at least a half-hour before putting it in the dye bath.

When using wool fiber, make sure the water temperature gradually rises or lowers, so the fiber can get used to the change. For most items, hang to dry. For delicate items like knitted wool sweaters and garments, it’s best to lay them flat to dry so they keep their shape and don’t stretch.

4 ounces (113 g) wool fiber
8 percent (1 1/2 teaspoons) alum to weight of fiber
7 percent (1 1/2 teaspoons)
Cream of tartar to weight of fiber

Soak the wool fiber in a bowl of water for at least 1 hour.

Place the alum and cream of tartar in a cup, add some boiling water, and stir to dissolve. Add the alum and cream of tartar mixture to a dye pot full of enough water to cover your fiber, and stir.

mother earth news fair 2018 schedule


Next: April 28-29, 2018
Asheville, NC

Whether you want to learn how to grow and raise your own food, build your own root cellar, or create a green dream home, come out and learn everything you need to know — and then some!