I like to make MFF and I was wondering how long well it keep untill I need to use it, I am planning to make a cake but I want to make the MFF couple days or so, well it still be good to use

Indefinitely ..seriously...

I have MMF that I made last April that is still good. if you are talking flowers or decorations, it is years. The longer the more sturdy they get..

JUst heat them up a little bit to soften them, so you can roll them out.

Does it need to be refrigerated if you store it for a period of time or just left at room temp? It's awesome that you can keep it that long.

I've used it at least 2 weeks after I make it and kept it at room temp. I just nuked it and worked with it some and it was fine.

I've used some 8 months after the fact and had it work beautifully.

I don't think it needs to be refridgerated since MMF has bascially marshmallows, icing sugar, and crisco in it - all of which pretty much have an unlimited shelf life and don't require refridgeration!

It does not need to be refridgerated and can last forever!