Preface: I just want to briefly preface these directions by saying that this is the method I use at Wind Rose. There are many wonderful variations on how to dye wool of which this is just one. I have developed it over the course of dyeing over a hundred pounds of fiber. I have not gotten into exact recipes for achieving different colors. I will let you have the fun of creating your own favorite hues.
How To Dye Wool Roving
(*The utensils you use should be exclusively for dyeing.) When I dye 100% wool, I dye 4 ounces at a time. it is a comfortable amount for me to work with using a 3 gallon pot. First I prepare my dye solution. I use 2 cup canning jars. They are glass jars with an air tight lid. I combine the whole jar of Jacquard Dye (.5 ounce) with 1.5 cups of warm water. I close the jar and then shake it until all the dye powder has dissolved. I label my jar because this much dye will last a long time. I keep it stored in a dark, cool pantry.
Next I prepare my roving. I weigh out 4 ounces and then I put it in a bowl of water to soak for at least 30 minutes before I start to dye. This helps the wool to dye evenly. If you are working with locks or unprocessed wool, you will need to clean the wool well before dyeing to remove any vegetable matter and oils from the fiber.
When I'm ready to dye, I fill my pot with luke warm tap water leaving 4 or five inches from the top. I turn my stove on to medium heat to let the water start to warm up. Then I take out a glass measuring cup and the dye solution I made earlier. How much dye I use really varies depending on the color I'm trying to achieve. Two tablespoons of my dye solution is enough to dye my four ounces of wool a medium shade of most colors. Use less if you want a pastel or light color and more if you are going for a deeper shade. If the dye solution has been sitting for a while, It's good to shake it up before opening the jar. Then I mix my dye solution with about one cup of warm tap water in the glass measuring cup and stir. (This is the perfect time to mix colors and create your own special recipes.) You could pour the dye solution right into the pot and stir. but I do this extra step just to make sure the dye is well mixed before going into the pot.
Now add the dye water you have just created to the pot. Stir well to make sure it is mixed thoroughly. Now it's time to add the wool. The water in the pot should still be just warm at this point. You don't want to shock the wool by putting it into a hot pot. It will start to felt. Squeeze the excess water from your wool and then gently place it into the pot. Make sure that are no tight twists in the roving. The next 10 to 15 minutes are critical because it is when most of the dyeing is going to take place. I give the wool a gentle stir to make sure the dye water is getting to all of the fiber. Now it's time to add your acid. I use distilled white vinegar. You only need about one fourth cup. After I add the vinegar, I give the wool another gentle stir. You don't want to over agitate the wool or this too can cause it to start to felt. By now the heat should be rising in your pot. I stir about every 3 or 4 minutes turning the wool over almost like the folding process used in baking. The goal is for the wool to dye evenly, not to mix it up. You've already done the mixing before you put the wool in the pot.
A lot of dye directions talk about letting the heat get to just below boiling. I don't think it needs to get quite that hot. I wait until I see steam start to rise but the water is not starting to bubble yet. At this point I turn the heat down to medium low. After the first 10 minutes, I stir less frequently. Usually, in 20 to 30 minutes, the wool has completely absorbed the dye and the water is clear. When the water is clear, I place a strainer in the sink to catch the wool and I pour the the contents of the pot out over the strainer. You don't want to rinse your wool with cold water. That too will shock it and cause it to felt. If the dye water is clear, there is no real need to rinse the wool. The dye is colorfast and will not bleed. After I strain the wool, I use a towel to blot out any excess water. Then I lay it out on a fresh towel to dry in the sun.
Final Note: I just want to say in closing that this is a general explanation for dyeing wool. When dyeing other kinds of fibers, adjustments have to be made to accommodate their specific characteristics. This is a great place to get started. I intentionally strayed away from too many detailed calculations (weights and measures) to keep it user friendly. Anyone should be able to do this in their kitchen and achieve success. As with anything, there is a learning curve. The more you do, the more comfortable you will feel and you will find yourself perfecting the process for your personal needs and goals. Just remember to have fun along the way!