This episode explores the difference between green and black olives, and why not everything that goes into beer processing is listed in the ingredients. Matt travels to South Africa to visit one of the country's largest olive orchards in the Western Cape, where he discovers that black olives are just riper green olives, but that both need a year's soaking in brine to make them edible. In Spain, Kate is shown how mass production factories make super black olives found in pizza and salads. And Matt heads to a small brewery near Belfast to discover if it really is just water, hops, barley and wheat in beer.