I had my first attempt making marshmallow fondant last night, did the same thing for two batches and came out with very different results. For the first batch, I used 16oz mini marshmallows, 2.5 tablespoons of water, microwaved for about 2 minutes in 30 second intervals, then added it to my powdered sugar and started kneading. I anticipated 8 cups of p. sugar, but by the time I got to 7, the ball of fondant was so dry it was just tearing. It would barely stick to itself. I attempted to add a teaspoon of water to it, but it just became incredibly sticky and wasn't getting any more pliable. Regardless, I covered it in crisco, double wrapped it and stuck it in the fridge.

For my second attempt, I did the exact same thing, dumped it out on my sugar, and this time it took over NINE cups of powdered sugar and was still very soft and elastic. It was still slightly sticky when my knuckles went into it, but after literally about 9.5 cups of sugar and it still being nicely elastic, I figured it would be enough . I covered and stored it the same way.

What gives? The only thing I can think of was that the second batch was slightly warmer...maybe 2.5 minutes in the microwave. Any tips will be helpful, I'm not a fan of inconsistency when I'm baking! Thanks for any help anyone can give!

Did you ever watch the youtube video's on how to make it? That's how I learned. The key is to add a little powdered sugar at a time and it will be super soft, until enough is added (I'm sure you know that). This video is the best by far, because it tells you everything you could possibly need to know about making marshmallow fondant.

Also, when I have to add water, I just keep putting a very thin layer of powdered sugar on the outside by blotting the fondant onto the sugar, put more crisco on my hands, knead, and keep putting a very thin layer of sugar on the outside...sometimes it takes quite a bit of water to soften it back up again, but if you add to much water, just add more sugar to harden it back up again.