These are made generally from Beech in Austria and in Switzerland Fir or spruce is used.
The Swiss use fir and spruce for most things that are made of wood. So we will have forms, press tables, vat lids, press plates, curd scoops, etc. made of fir and spruce.
Maple and Beech are good hardwoods for using in food contact. Fir and spruce are good softwoods. These are neutral in regards to flavor, and not overly hospitable to microorganisms.
But my forms like this are made of high density plastic, and if you can get plastic hoop forms do so. They are easier to take care of. The wood ones need re-shaped every few years and absorb the whey.