“Is it true, that the baking time in foil depends on this, which side is adjacent to the product?”
The shiny side of the aluminum foil retains heat, the matt one lets them through. So in order to bake faster, for example. beef, you'd better wrap it with the matte side facing out. The wrap is hot, baked chicken in foil with the shiny side on the outside – will cause, that it will stay warm longer. We can bake vegetables in the foil - approx. 15 min, fish - 30-45 min, poultry – ok. hours, beef - one and a half to two hours. Before baking, grease the foil on the inside with oil, food does not stick.