Getting back to DD, it’s quite interesting to watch a DD truck unload at a DD store. Check out the cartons of donuts, they all have (I don’t recall which) either an OU or OK hechsher on the carton. Of course, once those cartons are opened and the donuts come in contact with the triefess is the stores, that’s another story.
I’ve asked to see the syrups used for flavorings, and they all are under OK. When you ask for something like a mocha coffee, they’re combining their regular coffee with a few shots of the syrup (it’s in a large pump bottle).
Even when I’m in one of the kosher DD’s, I don’t buy the donuts. Not because of kashrus, but I just don’t care for donuts. But I’m comfortable based upon opinions of the major kashrus agencies that the coffee is not an issue in DD. Again, USA milk comes from cows. However, I was very surprised to see, during a stopover in Europe enroute to Israel, many “frum looking” people having not only coffees in the airports, but things like lattes with whipped cream. Didn’t they realize that the USA doesn’t oversee milk in other countries?