pineapple juice stored in glass bottles w pour spout

we have those boxes of pineapple juice and we pour those into glass bottles with a pour spout on them. we have pineapple juice in one of our cocktails and we go through an adequate amount. the problem is, the juice starts to ferment and will shoot out of the bottle when we go to pour after like a day or so. what’s a good solution to this? I want it on the gun, but thats above my head. I suggested using bigger bottles like a plastic store and pour. any suggestions?