Lab rat fun: Pepsi beats Coke

In the latest chemico-visual fun from our chums at Nottingham University, we learn that aluminum is an amphoteric substance, which means it can react as an acid or a base. Coke cans are aluminum, but Pepsi�at least in the UK�comes in steel, which isn’t amphoteric. So Pepsi stays out of the corrosive baths. I’m not sure this means that Pepsi is the pinnacle of the entire universe�but that new logo looks much better for not bubbling away in a vat of acid.

The experiment provokes a question, however: how do the sugar-water vendors ensure their aluminum cans don’t break down due to the acidic soda contained within? Both Pepsi and Coke contain phosphoric acid, and any carbonated soft drink contain carbonic acid, too. They’re not strong enough to dissolve the can (although they do a number on your teeth). But the reactions would change the taste of the product, and not for the better. The taste of the product is preserved by a plastic lining, which is often manufactured with controversial�and undeniably toxic�Bisphenol A. Bottoms up!