"What bread do you like?"
Translation:Jaki chleb lubisz?
Although "jaki" could mean what you call property, I'd rather expect it to mean the type. Or maybe, type is a property as well. But "który" sounds as if you had a closed set of potential answers to choose from. It could work, but "jaki" seems a lot more natural to me.
Compare with a simple question giving a choice: Który chleb wolisz, biały czy razowy? = Which bread do you prefer, white or whole wheat?
When talking of general type, we'd probably say "What (kind of) bread do you like?".
The use of "which" exactly implies a choice from a closed set of options, for example looking at a selection in a shop. (And what a selection you get in Polish bakeries!)
Yes, it is natural when you e.g. have a conversation with someone and this person asks you what kind of bread you like. Then you want to ask the same question, so you use "ty" to make a kind of contrary. :) And you should also add "a" at the beggining of the sentence, so it goes: "-Jaki lubisz chleb? -Zwykle jem biały chleb. A jaki chleb ty lubisz?", meaning, "-What bread do you like? -I usually eat white bread. And what bread do you like?".