Hi,

I made buttercream and ganache on April 15th. The leftovers have been covered and in the refrigerator since then. The ganache is a simple 50/50 chocolate/cream recipe. The buttercream has butter, cream, powdered sugar and vanilla.

I'm wondering - could I still use these? And how long can they stay in the fridge before they go bad?

Thanks in advance

buttercream for up to 2 weeks if kept in fridge, but ganache I cant help you.

Ganache holds up about 2-3 weeks in the fridge as long as the expiry date of the cream is within that time frame. I have seen as much as 1 month, personally, 2 weeks and it hits the garbage.
Hope that helps!
Hugs Squirrelly