"Is that good?"

As I was checking out at Trader Joe's the other day, the cashier scanned one of my items and asked, "Oh, is this good?"

I guess they're trained to make conversation, but the item they had scanned was 2% milk. 

What came out from me was a direct answer: "I just got this kind because I'm on my way to the subway and I don't want to walk to the store near my apartment"

Followed by a too-late make-up: "... But I'm sure it's good though!"

But it did get me thinking, how do you know when it's good milk?

Bad milk is an easy one to pick out, but do you ever really notice good milk in your coffee/in your cereal/with your steak if you're Jim Harbaugh?

And why has this been in my head on-and-off ever since then?

I Have No Mouth and I Must Ice Cream

Seen at a Van Leeuwen

Disclosure: I've never read the story and have no idea what it's about