I've always called them ginger beer's and have over 30 of the typical black designs with "Ginger beer" but actually was going to support Harry's terminology because I remember digging a blank one with "O'Keefe's Beer" engraved at the bottom.
After looking in my books, I now have to disagree with Harry......

These are paper labels that say GINGER beer. The one on the left (Stone bottle) is what I have.
I also have the exact same style as the one that started this thread except the little engraved circle at the bottom is from Quebec.
Here it is in the book.......

Hard to see but the bottle (Left) has the engraved circle at the bottom. Paper label also.
Looking through the couple of other plain stone types, I have one that just simply has an engraved maker......
I have a few other typical Ginger beer bottles (Black designed label) that say Mineral water also.
So, I don't disagree that some "Ginger beers" were actually just ale.
However, my conclusion is that you can't generalize the stone bottles that are blank with only the engraved circle (like the one in post #1) as "Ale."
More importantly, To use a defense like "That's what the archaeologist's classify them as" is not wise.
In the relic hunting world, I have endless data that prove archaeologist's classifications are wrong in regards to hundred's of artifacts.
With limited field work, most times they quote an academic's hypothesis from decades ago and the information is quite dated.
They are not the authority on everything and I would wager someone like Harry knows a 100 times more about bottles than the "academics" do.
Interesting debate!
Cheers,
Dave.