Four star rating... not because it's the best museum in the world, but because it's a freaking MUSTARD MUSEUM in the middle of DOWNTOWN MIDDLETON! What... the... what?!?!?!!
It's not very big, and it's completely free. You can spend 30 minutes to several hours in there and feel satisfied with your experience. It's irreverent and random, and you'll leave with at least a half smile on your face.
Massive pro is the staff. They are all incredibly knowledgeable and friendly. My father-in-law loves the fact that he can buy a mini hot dog for a buck, and try various kinds of mustard on it.
I left still not loving mustard, but I did enjoy my 45 minute visit. I'd highly recommend popping across the street to the Free House afterwards to wash down that mustard with a nice local beer!