We press the apples through net curtains which are really good at sieving out "bits".
to prevent the juice going brown add half a teaspoon of ascorbic acid (vitamin C) to each bottle then pour the juice in up to the top before pasteurising. We pasteurise ours in a water bath. Then cork it with the juice overflowing. That way, once the liquid cools and contracts it creates a vacuum and there are no little mould spores..... But even a little bit of mould on the top doesn't alter the taste. If ours have got mould then I just pour it through a tea strainer. Tastes fine and lasts for over a year.