I have some left over mmf that is wrapped in saran and sealed in a zip lock bag, how long will this keep?

6 months or more.

I once kept some almost a year.

well sealed of course

ok thank you for the help

Wow, that is a long time. I made my first batch of mmf and I could not believe how good it tasted. I wanted to make some to have ready to use but also did not know how long it would last.