I make my own MM fondant and I live in Tx and the Humidity is terrible so the MM fondant dosent set up. I was wondering how much Tylose powder to add to make it harden up like gumpaste?

I use 1tsp on 100g, but you might have to adjust it if its a high humidity area. Also this is for store bought fondant (pettinice)
Try a batch and see how it goes, if its too stiff add some more fondant, too soft bang in more tylose

Thanks I'll give it a try!