I totally agree with AngelFood4, the amount of shortening you use can make or break your MMF. I got so sick of my inconsistent results! But alas, I decided to try again. I realized that if I used too much shortening I got the silly puddy effect, if I used to little it would just tear, no elasticity.
16 oz mm
2 tbs water
1 tbs corn syrup
1 tsp vanilla
2 lbs powdered sugar
Melt mm with water in microwave in 30 second intervals until smooth. Stir in corn syrup and vanilla. Pour 3/4 of the powdered sugar in to the mm mixture and stir (or use a kneading hook and a stand mixer) until it is too thick. I DO NOT coat the bowl with shortening. Lightly cover your work area with shortening, as well as your hands and knead in the rest of the powdered sugar. I keep applying shortening to my hands like lotion until the mixture is not sticky. If it is tearing, or I need it softer I add corn syrup a few drops at a time.
After fondant has reached the desired consistency, work it into a ball. Smooth it over with some shortening. Tightly cover in saran wrap, seal in air tight container, and let set for several hours, or at least over night.
I have never been very good at following a recipe, I like to add and take away to my taste. MMF is not so easy to do that with. Now that I follow the recipe very strictly I love MMF!!