Luke Skywalker's life as a hermit in Star Wars: The Last Jedi looks like it was pretty peaceful overall. He lived on a beautiful island where he got to be alone with his thoughts. He did some fishing, and had books to read. However, the place where he got his milk left something to be desired.
Luke Skywalker had to physically milk a large alien creature and what he got for his efforts was a strange green liquid. Luke appeared to like it, but how did Mark Hamill actually feel about the stuff? It turns out he liked it quite a bit, because it was really just coconut water. The stuff he drank wasn't even green.
It seems that the green color was added in post production, so Mark Hamill was really just drinking coconut water. It's not a taste that everybody loves, but it works for a lot of people, including, apparently, Hamill. His little emoji added to his tweet seems to make it clear that he loved the stuff. Hopefully that was still the case after multiple takes.
This is in contrast to the famous blue milk that we see Luke Skywalker drink in the original Star Wars: A New Hope. Hamill has stated before that the blue stuff was "life-long milk" that had been dyed blue and that the stuff wasn't very good at all.
Blue and green milk have since become significant parts of the Star Wars universe. When the team behind Star Wars: Galaxy's Edge at Disneyland spoke about the things they wanted to be sure guests were able to do, drinking blue milk was always one of the top items. There's something about drinking blue, and then green, milk that makes the experience of being part of Star Wars feel authentic. It's one of those minor details that makes everything feel more alien.
Of course, Disneyland doesn't want blue or green milk to taste bad to anybody. Both items that are available in the new theme park land are closer to milkshakes than actual milk. They're also not actual milk, as both are rice-based beverages. The blue milk has a citrus taste, while the green has more of a melon flavor. Although, it's certainly possible that there is some coconut water in there as well. Rian Johnson himself is a particular fan of the green stuff.
I got to try both during a pre-opening visit to Galaxy's Edge, and I preferred the green over the blue milk as well, though my guess is most people will prefer the blue milk.
It's more than a little humorous that in a movie franchise that includes swords made of light and mind-control magic, the beverages have becomes some of the most iconic elements. As the Star Wars universe expands, one certainly has to wonder if more alien foods and drinks will get created within the films and television series, just to help fill out the world and make it feel complete.
Of course, then one has to wonder how long it will be before those new foods and drinks become available inside the theme park.