Decarb HBO?

I read that it was necessary to decarb HBO before cooking with it. I put it in my toaster oven at a temperature of about 200 degrees Fahrenheit for about twenty minutes. All of the recipes that I read online said that the bubbles would stop forming, but after the twenty minutes, my HBO still has bubbles in it! I don't want to waste it and burn off the medicine, but how do I know when it's ready if the bubbles are still apparent?