When the shaker won't open, you can use the back of a fruit knife to gently tap the lid of the kettle, or use the back of the knife to tap the bottom of the kettle, which can help open the shakerIf the lid and body of the jug still can't be separated, you can try a gentle bump with a shaker, or tap the edge of the jug with the back of a fruit knife, which may cause some wear but will solve the problem.
Shakers usually evolved from ancient Greek kettles and come in a variety of shapes like calyx, bell, etc. They usually have a handle that helps mix wine and water. Shakers come in a variety of designs, from simple bowl shapes to taller tank shapes, and handles can be cylindrical or spiral
