How do I limit priority mail on certain items?

[LiveWire]

Hello,
I have looked in the FAQ area for this question but I don't see it anywhere. I am using zencart V 1.3.7 and I ship most product out with express mail overnight, Now I have grown and added dry goods that can ship with priority mail. How do I set up priority shipping for only the dry goods and not make it an option for the products that have to ship express?

[LiveWire]

Is there any way for me to do this?

[Ajeh]

Is there something in the products table to distinguish the difference between dry goods and all other products?