If I placed my kosher food on a non-kashered surface that I knew had never been used for food, is my food still kosher?
I would be interested in whether there could be concerns of bugs--but that is not my main question. My main question is whether particles or transfer of non-food can ever make something treyf.
If not, what is the property of food makes it able to treyf something up? (Or, put another way, "What makes something 'food'?") Is it the property of taste? Good/appealing taste? "Taste or nutrition"? Something else?