I made the dye bath using a 1:1 ratio of berries to fiber. In this case, the blueberries had been left behind in the fridge at work and had started to get wrinkly and soft. Instead of throwing them in the compost, I took them home for dyeing. To get the maximum amount of color from the berries, I added a small amount of water to the pot and crushed the berries with a potato masher. (I did this without the water at first and ended up squirting berry juice everywhere...)
After keeping just below a simmer for an hour, I strained out the berry pieces and added the wet fiber. The dye bath looked like a gorgeous pink/purple, and I was really hoping that would transfer to the fibers. When the fiber was rinsed and dryed, it ended up looking more like a blue-ish lavender. It is still a lovely color, but definitely shows how unpredictable natural dyeing can be.