Yes! The way dark roasted coffee operates is that it tastes best when milk and sugar is added. I always liken my milky sweet dark roast cups to little donuts. The sugars are pushed so far in the development stage that they begin breaking down. The resulting dark roast benefits from sugar being added to it after its been brewed. Because these sugars have broken down so much, and the structure of the coffee bean is so brittle, dark roasts generally have thin mouthfeels. By adding milk, you beefen up that body and add a gentle and smooth texture to the coffee. If you like milk and sugar in your coffee, I highly recommend brewing up a dark roast!
Nope! Here’s the official skinny on caffeine content in coffee. Almost all Arabica coffee has the same amount of caffeine, period. Caffeine also has a melting point of 455 degrees Fahrenheit, which will torch a coffee bean. So, if you’ve got an ultra-dark roast, the roast itself has actually burned the caffeine out of the coffee bean. Many people assume that roasty flavors equal a “stronger” cup of coffee (which to many means more caffeine), but that’s not the case. Darker coffee is more brittle, and will extract easier, so technically you can pull more caffeine out while brewing a darker coffee, but it has nothing to do with the roast level.
Dark roast coffee means that the coffee is pushed up to, and sometimes through, second crack. Second crack refers to the sound the coffee makes after the heat of roasting fully develops all of the sugars within the coffee bean, and begins to take its toll on a the structure of the bean itself. The “crack” is actually the coffee beginning to break apart. This style of roasting obliterates any flavor from the green coffee at all, and bittersweet, roasty, and smoky flavors dominate the profile of the coffee.