Cheddar, hah I think you mean 'merican cheese
Cheddar is a village in Somerset in Britain :)
According to Wikipedia cheddar is the most popular cheese in the UK but not, it turns out, in the US. In the US the most popular cheese is apparently … mozzarella.
Not sure what any of this goes to prove (that Yanks eat a _lot_ of pizza?) but I guess I'm trying to say that I associate cheddar with British cheese-making in the same way I'd associate brie with French, edam and gouda with Dutch, feta with Greek, manchego with Spanish, and so on.
Someone who is buying real cheese in the US is not really in the wheelhouse for soylent, we are probably talking about a big block of mass-produced yellow cheddar here. Most likely it is being stored improperly in a ziploc bag or similar and the retained moisture is causing premature mold growth.