1In a medium saucepan over low heat, mix soy sauce, water and butter. Stir until the butter has melted, then gradually mix in the sugar until it is completely dissolved.
2Place mushrooms in a slow cooker set to low, and cover with the soy sauce mixture. Cook 8 to 10 hours, stirring approximately every hour. Chill in the refrigerator until serving.
Footnotes
Easy Cleanup
Try using a liner in your slow cooker for easier cleanup.