As with our apple juice and apple cider vinegar, our approach to making dried apple is also rather simple. All we do is peel, core and slice apples and put them on a covered 18 metre by 2 metre table, on a bright sunny day. Absolutely nothing is added to the fruit except sunshine. When we first started drying fruit in 2002, we tried buying certified organic lemons, squeezing them and dipping the sliced apple in the resulting juice, to keep the dried apple a lighter colour. This was an extremely time-consuming and messy exercise, and the undipped fruit was not all that dark in colour in any case. So we abandoned dipping in lemon juice a long time ago (and we never even vaguely considered using sulphur).
The secret to keeping the fruit a lighter colour without additives is a short drying time - in our drier, thin slices of apple or peach will dry in six to eight hours on a bright sunny day in summer or early autumn. The only problem is we can't solar dry fruit here after the end of March, because we simply run out of strong sunshine about then. So we have never dried a variety that ripens later than Jonagold.