The supports are long steel bars that go through the shelves and into the studs in the wall. We predrilled holes for them before we tiled. We used oak planks seamed together to make a solid wood shelf." I love the hanging coffee mugs.
The Chic Technique: Free standing kitchen pantry. You could make something like it from a TV armoire , or other wood cabinet you no longer use. Or a craft closet! vertical free standing cabinet by The Bespoke Furniture Company