You have just purchased some white silk cocoons and want to dye them.  Here's the easiest way I know and you can do it in minutes in the microwave at home.  This method also works for the silk carrier rods, as I dye them both together.

Before you start, assemble the following items:  white vinegar, the cheap kind; food coloring, from the grocery store baking isle; an inexpensive Pyrex type glass 2-4 qt baking dish with a lid, that is microwave safe; and a measuring cup and a measuring teaspoons.  I prefer food coloring or even unsweetened Kool-Aid works, but the food coloring is more concentrated and actually cheaper in the long run. 

Here's how, take you baking dish that is microwave safe, add about 3 cups of water and a 1/4 cup of vinegar then add you favorite food coloring to the water. The amount of food coloring will vary depending on how dark you want the cocoons to turn out.  I would suggest about a half of teaspoon to dye 12-15 coocons with the first time.  Experiment with the amount of food coloring to achieve the intensity of coloring you want.  Keep notes on how much food coloring you use to how much fiber you put into the dye pot.  Your three basic colors: red, blue and yellow can be mixed to give you purples, oranges, and greens, and many other colors.

Once you have your dye bath mixed up add your silk cocoons to the mix.  Cover the casserole dish with its lid and microwave on high for three minutes, then open the door, use a pot holder to remove the lid as it might be hot, and stir the cocoons a second.  Put the lid back on, microwave on high for another 3 minutes.  You may let the dish cool in the microwave or use pot holders as the casserole dish will be very hot, and move the dish to a hotpad to cool to room temperature.  I like to gently run cold water after the cocoons cool into the dish being careful to keep the stream of water from contacting the cocoons.  I rinse for about a minute in running water.If you are trying to keep the cocoons intact and keep their shape, at this point the cocoons are very soft and you will need a spoon to carefully lift them out of the dye bath when they cool.  Then dry the cocoons on a rack where the air can circulate freely around them.  I have an old cake cooling rack that I use.  If the pupa is still in the cocoon, you will really need to make sure the coon is super dry before storing or else you will have the cocoons go bad on you.

If you really want the dye to soak into the cocoons will, soak the cocoons for 24 hours, before you dye in a bath of room temperature water and about a teaspoon of dish soap.  I like Dawn or Joy, but all work nicely.  The soaking of the cocoon will enable it to take up the dye more evenly.

Some extra helpful things you can do...I have a food dehydrator that I use in winter to dry my cocoons in, or in the summer I put them out in the sun to dry.  If you want to spin the silk from the cocoon, cut out the old worm inside first, then degum the cocoon before dyeing it.  When you degum the cocoon, it will no longer hold its shape as you have removed the sericin from the silk which is the sticky substance that holds the cocoon together.  The best degumming recipe I know of is by Celia Quinn and is on Treenway's web site.  The web site has a lot of information on how to spin the various types of silk, also.  I have gotten permission from Treenway silks to go ahead and post Celia Quinn's Recipe for silk degumming in this article. So, it is listed below:

Degumming Recipe

by Celia Quinn

used with permission from Treenway Silks

1 pound raw silk ( with sericin 'gum')

4 oz washing soda ( sodium carbonate)

4 oz soap (grated Ivory soap bar)

1.  put washing soda and soap into pot with a few inches of water

2.  keep at low simmer until soap and soda dissolve  

3.  add enough water lukewarm water to float silk comfortably

4.  add silk and simmer until soft ( 1 hour) remove a sample and

      rinse to determine if it is soft enough  

5.  rinse while hot, to remove most of the sericin, soap and soda

6.  add about 1/3 cup vinegar to neutralize alkalinity and soak for

      10 min  

7.  rinse in clear water

   Silk cocoons in the dye bath ready for the microwave. 

  Silk cocoons and rods being rinsed after cooling to room temperature.      Very carefully lifting the cocoons out after draining in a colander.         Silk cocoons outside on a warm day, drying on a cake cooling rack.          In foreground cocoons that got smashed as I wasn't gentle enough lifting them out of the dye water.         

If you have any questions about dyeing silk cocoons or other forms of silk, just email me and I'll try and answer your questions.