64oz. Grape juice on sale

[ckmk47]

How can I know if the current bottles in shoprite or pathmark are the non-mevushal or not?

Check for little words near the hechsher.  "mevushal" or "not mevushal"

All wine and grape juice will say if they are mevushal. AFAIK
(If they're not, they may not say anything.)

[cubicles]

How can I know if the current bottles in shoprite or pathmark are the non-mevushal or not?

The big glass bottles are always non mevushal

and the plastic are always mevushel except if it has BIG words non mevushel
(not sold in shoprite or pathmark)