Cider with Brett

I have a cider with the dusty white bulbly crust. It smells fine smelled vinegarery adcitic at begining forgot for a monthish and found this. I guess my washed yeast got infected? But it tasted good before the pellicile a month ago. How long do I let it sit with brett or secondary?

Did you use pasteurized cider? If not that might be the source of the microbes.

I have my first funky cider still sitting in secondary after ~9 months. Cider is pretty fermentable, so there really isn’t too much for the bugs to eat after primary fermentation is complete. Mine just has a “rustic” aroma, and a subtle acidity that helps to add to the apple character. You can bottle it as soon as the gravity stabilizes, but I find cider ages well so I prevent myself from drinking it by bulk aging it.

I just used cheap frozen cider and cinnamon was gotten to backsweeten for wife she didn't like my complex crannapple tart cider. Oh well hope I got something good and get a new carboy for a basic cider

How do I know when it is finshed?

gravity readings

How low should it go?

cider will always go down to at 1.00 unless you cold crash and rack causing a stuck fermentation.

if its at 1 or lower then its done, if its higher let it sit.

brett takes time to really develop character, the longer you let it sit the better it could get