Beer can be bought from the supermarket in aluminium cans or in glass bottles. Why aluminium? Why glass? Both materials, together with the shape adopted for the container, are able to give rigid containers which do not readily deform under the handling they receive in the supermarket and getting to it. Both materials are resistant to chemical corrosion by the contents – though some people swear by glass as they feel the aluminium does give some ‘ taste ’ to the beer. Both materials are able to keep the ‘ ﬁ zz ’ in the beer and stop it going ﬂ at, i.e. the gas in the beer is not able to escape through the walls of the container. In addition, both containers can be produced cheaply and the material cost is also low. Both materials can be recycled. The main difference between the two is that the glass bottle is signiﬁ cantly heavier than the aluminium can.