a potential problem is that it probably won't taste great for a while, when you ferment it fresh juice like yours goes from tasting great to tasting really weird, as fermentation is finishing, to tasting great again after it's really done fermenting and everything settles out. if you just loosen the cap you can get through the first phase but you might struggle to keep it sanitary long enough to give it time to clear and age, say a month. and then you're going to need to either bottle it or drink the whole thing pretty quickly.
you could try this: let it ferment for a while, taste it occasionally and when it's still got a hint of sweetness to it, stick it in the fridge (get/repair/steal/borrow one) for a few days, it should start to clear up. pour the clear upper part off the sediment below (don't be too fussy), and drink up! with a bit of sugar left unfermented the young cider will be more palatable and possibly delicious.