Mould?

[GurraG]

I made a batch of hard cider using only apple juice and ale yeast, no added sugar. A couple of weeks after I had racked it to secondary I noticed something strange on the surface of the cider.
Sorry for the bad picture, in realiry the "crust" is white. It is a flaky layer, about half a millimeter thick, looking almost like candle wax. The cider smells and tastes ok, btw. Is it mould or something else that's nasty?

 

[LeBreton]

That's definitely an infection, but since it still tastes good there is time to save the batch. Carefully rack the cider out from underneath the layer, leaving it behind, to a fresh container. Dose with sulfites, and top up to minimize any headspace if you're going to age at any longer. Otherwise, you can go ahead and bottle asap and pasteurize or cold crash in the fridge to prevent re-growth of the infection.

 

[GurraG]

I was planning to bottle carb it, would it be a bad idea to do so and pasteurize? Or should I go with sulfites and keeping the cider still?

 

[LeBreton]

I was planning to bottle carb it, would it be a bad idea to do so and pasteurize? Or should I go with sulfites and keeping the cider still?

I'd do both. Sulfites will not stop fermentation, but will help prevent their coming back while waiting for carbonation to finish, pasteurization will definitely kill those evil microbes.

 

[GurraG]

Thanks for your advice!