The GBP aficionados may make the distinction, but that's the wrong distinction to make. SCOBY is an acronym, and a true GBP is exactly that, a symbiotic colony of bacteria (Lactobacillus hilgardii) and yeast (Saccharomyces florentinus). What you're describing is the difference in structure of...
Depending on your use of the sweetpotato you may not need to mash it. If you roast it, you needn't mash it. When you roast the sweetpotato, what you are essentially doing is mashing it, only with dry heat instead of in water. The only real purpose of the water in the mash process is to...