Traditional fondue is made with aged cheeses, and usually requires the addition of cornstarch or flour to help alleviate separating and graininess. Even with that, making it can be tricky. On the other hand, Rheinlander fondue is made with processed cheese instead of aged cheese, so clumping and separating aren't issues. This makes this easy fondue recipe practically foolproof, and essentially guarantees a smooth, velvety outcome.