Yes, I've seen lemon juice has the same effect but how do you use it ? - T

The problem is the same, as the juicer's filtering is not perfect and a proportion of of a very fine sludge ends up with the juice and it's that sludge which seems to contribute significantly to the brown colour. The sludge goes really s****y brown and is a really a rather unpleasant looking 'material'. I do agree that in the end the effect is not at all serious, but if I can find an easy way of controlling the discolouration that would be good.

I'm going to experiment with filling the apple bucket with a pretty dilute solution of the ascorbic acid such that each fruit carries a small drop into the process.

Rob