I am making my first ever fondant cake using MMF. I think I may have added too much shortening, and/or overmixed it because it is both gummy AND tearing. Not soft and pliable like it's supposed to be.
It's resting on the counter now...if I start over I won't be able to let it rest for more than an hour or so (and I'd have to go shopping) so I'd really like to avoid starting over.
I don't have any glycerin but...what might help? More PS? Corn starch? Something else?
If it's gummy (I'm guessing it's sticky?), then I would think you didn't add enough powdered sugar. I would start by adding more powdered sugar and knead that in well to see if that helps. If it's greasy feeling , then you've used too much shortening... adding more powdered sugar should help with that too. Good luck! HTH