Nice! Yes, caerphilly has that tang to it when young, but that mellows fairly quickly as you age it so it's a matter of finding the right time for you. Four weeks is a pretty quick cheese. I've got one that is now around 4 months, and I'll be aging it out a bit longer. This is the longest I've ever aged a caerphilly, and I'm not shy on extended times (I've got a few cheeses that are still uncut after 3 years). Anyway, glad to hear this worked out well for you. It is a great cheese to start with, both because it is tasty and because you get feedback on your procedure very quickly.