Hello Anne,
Is the handle of your jug hollow? I've just seen a tankard in the same design in a local charity shop. It has the same tapering shape, moulded bands to the body and an applied hollow handle and looks as if it is from the same maker.
The tankard certainly isn't bottle glass, its in a smoky grey colour lead glass, quite similar to some Wedgwood pieces I've seen recently. To my mind, your jug looks better than bottle glass though it is difficult to tell from the picture and i am not so familiar with Empoli.
I'd be very interested to hear any further suggestions as it is a nice piece and looks somehow familiar, yet I cannot place it as yet......
Steven