OK, I know, that maybe for some of you this post will be ridiculous, but in fairness it truly makes a difference.
So we have two sides of aluminium foil (also known as tin foil) and each of them help food to get warmer or keep the temperature. For me it’s similar to the life blanket (or emergency rescue blanket) it has also two sides.
Shiny one – if you wrap your food with the shiny part on top, it would help to keep the warm, for example if you just bake lasagne and you wanna keep it warm for some time, cover it with shiny part on top.
Mat side – if you wanna heat something, then you need to cover your food with mat side on top. It will help penetrate warm quicker.