The lining in aluminum cans serves the purpose of protecting a drink’s taste by having beverages taste as they should for extended periods of time. Most commonly created from materials that range from epoxy resin to BPA-free alternatives, an aluminum can lining creates a barrier between the drink and the metal, preventing any sort of chemical reactions that could alter flavor. Basic beverages, such as sodas at pH ~ 3, have been found to leach metal ions from the can into the liquid should it not be lined, giving it a metallic taste. Typically, this is prevented by the lining in the can, which forms a thin protective layer against this interaction. Flavor stability is maintained even on long-term storage.
Epoxy resins containing BPA were originally used extensively in can linings because of their durability and effectiveness against corrosion. Recently, many manufacturers have moved toward BPA-free alternatives-such as acrylic or polyester-based linings-because of consumer concern over the health impacts of BPA. Both lining types are subjected to flavor profiles that ensure a beverage maintains its taste throughout its six-month to two-year shelf life for most drinks.
The move to BPA-free linings brought along some questions regarding what might be sacrificed in flavor retention, but independent testing at several major beverage companies such as Coca-Cola and PepsiCo reveals that today’s BPA-free linings perform no worse than traditional ones in preserving flavor. In fact, tests used to expose cans to changeable temperatures and humidity have concluded that the new BPA-free linings can preserve flavor to intended taste, without any perceivable flavor differences.
Quality linings can also result in the long shelf life of beverages in cans. Because of the avoidance of metallic reactions, linings can even make the acidic beverages stay stable for a longer period. According to James McDonald, a beverage expert, “A good can lining protects the flavor of the drink; it means what the consumer tastes is what the brand intended.” Besides flavor, linings today achieve high standards of safety from authorities such as the U.S. Food and Drug Administration (FDA) that constantly evaluates all materials in contact with food packaging.
To the brands and manufacturers who are looking for effective solutions, a high-quality aluminum can lining ensures flavor protection and safety, hence an integral part of delivering to consumers a consistent enjoyable beverage experience.