If the fumarate water is a thin layer, it's easier to scrape up after evaporation. The color change thing is pretty weird, but it always happens to me. I start with white or white with a little yellow, and it turns reddish brown during the water recrystalization. I use distilled water, so it's probably not something introduced by the water. Maybe one of our gifted chemists can explain?
The first time I tried this, I thought I had screwed up somehow because I had a gooey mess. I was advised to scrape it around and it would crystalize, which is exactly what happened, Yay!
Now I use a food dehydrator and I still need to stir it around when it's almost dry as it forms a skin over any thicker areas that don't let the stuff underneath dry well. I now have enough fumarate in the freezer to last a lifetime, but I love the extracting so much, I just keep going! Just started a new BLAB yesterday.
Pokey the Extraction Addict