Which shelf in a fan assisted oven is the best to use for making Yorkshire puddings?
I've always done them on the top shelf - leaving enough room for them to rise, if you use small tins.
I started before we had fan ovens & never changed the method when they were introduced.
The 'golden rule' has always been "as hot as you can get it", though you have to open the door at some point to pour the batter, so that also becomes, "as fast as you can do it [without burning yourself]".
I'm pretty sure this is going to be similar to many many other 'old but simple' recipes - there are no two people do it quite the same.
With Yorkshire puddings you need an extremely hot oven to get the best results.
In a fan oven you put them on the middle rack so that the hot air can blast over the batter, although the top rack seems to work just as well as long as you leave enough clearance for rising, and there will be a lot of that. However, many convection ovens do not go as high a temperature in convection mode as they do non-convection. Mine goes up to 200°C on fan, but up to 275°C non-fan, so I preheat the oil at 275, then I pour in the mix and turn down to 240 non-fan. As I use non fan I put it on the second to highest rack as the top would not leave clearance.
According to this recipe, you put your pudding on the middle rack.
"Adjust oven rack to center position and preheat oven to 450°F (230°C)."