I've made white chocolate ganache using a different white chocolate than I normally do. It didn't thicken up as much as it has before, and now that I've whipped it, there is no way it can be piped. I need to leave the house in an hour and I'm not sure what to do. Should I add some stiff buttercream to it? How can I make it pipeable???

I'm not really 100% sure but I would think the to add more chocolate normally...if it's already been whipped though I'm not sure that would would work now....I would think adding BC would give it a whole new existence making white chocolate bc not ganache...
I hope some has a more definitive answer for you!

Thanks very much for the suggestion. I didn't have a whole lot of time to do anything to it, and I didn't want to ruin it, so I ended up using the ganache as a filling for the cupcake and making a new batch of buttercream and using that instead. Thanks for the reply though.

I had read in the "Cake bible", if you muck up ganache, you can rewarm it to it's "liguid" state and try again.