I was slow to give Google Photos a try. It took their announcement of the end-of-life of Picasa to persuade me to give it a whirl.
It's really pretty amazing. I just typed "beer" into the search bar for my photos and this is the first set of matches it generated:
There are a few false-positives (mostly completely understandable) but most of these photos do indeed include some kind of representation of beer. I can't help wondering if the game we played for a while matching photographic keywords with strangers around the world against the clock somehow contributed to this wonder of machine image recognition. Or maybe they just employ a lot of interns at the Googleplex?!