Thanks for tag guys! @Growcoast @MidwestGuy
The reasoning behind freezing the material, and butane is keep from absorbing waxes, lipids and other undesirables from being picked up by the butane.
This will result in a higher quality extract at the other end. The color will vary based on the material being extracted. Trim in comparison to flower.
If you have a column that has space for the dry ice, this would also assist in keeping undesirables out. Here’s the the BHO extraction thread if you’d like follow along. Haven’t extracted in awhile, but we’ll be extracting some soon.