I split up my Indonesian beans and put some in the freezer in small jars because I use it in large (small?) part as a small component in my own blends.
One day I opened up a jar and it smelled like mint but I thought it was just something in the kitchen. Then the next day I smelled it again. This time I tasted it in the coffee, especially as it cooled. I asked my wife to smell the jar and she noticed it too. Then we remembered she used that jar to put mouthwash in for a day trip we took. We know for sure the jar was washed, but apparently this isn't enough.
So don't do this. Or do it if you like mint in your coffee. Coffee that makes your breath fresh? Maybe we're on to something.