So I'm bottling my cider and and I noticed when checking gravity that it is lightly carbonated out of the Carboy. Bubbles in the test beaker and the sampling glass. It carbed in my 68 degree basement and had a regular airlock, so no pressure during the 4 week primary. Is there something about cider that would cause it to have residual carbonation from my cool basement? Ingredients were apple juice and Nottingham ale yeast.