But Joe goes on to say that since the barley crop that year was unremarkable, they wouldn't have been drinking beer on Thanksgiving, but rather would have been drinking wine from wild grapes. While I won't deny that they could have had wild grape wine there, I will say that they probably also had their beer there. Since barley was hard to come by in the colonies, they made beer from other fermentables (such as pumpkin, molasses, and things - which Joe notes in the end of his article). To them, that was beer. Might sound questionable to us, but their beer was often made from things besides malted barley - they were English, not German. I think that to them beer was anything sort of brown and lower alcohol, or at least anything clearly not wine.
Furthermore, I would think that for a special occasion like Thanksgiving (assuming that all the folklore around the actual Thanksgiving holiday is correct), they would have had special beer for it. They were still part of the British Empire, and could import beer from England. They may have saved some of their fine British beer just for such an occasion. They must have had a beer geek or two with an extensive beer cellar just waiting to help out in just such a time of need. Perhaps they employed the currently still practiced activity of brewing special harvest beers. A whole field of barley - surely we can spare a few hundred pounds for a few barrels of real beer.
One final thought - to those who say "yuck" to the pumpkin, or molasses, or whatever in their beer: the pilgrims also had plenty of corn, which is commonly used today as a fermentable sugar in some of the most esteemed beers of the world. And who among us hasn't had a seasonal pumpking ale?
So when Thanksgiving comes next week, please drink beer. But only if you like beer. Drink wine if you want. Or even water. But since none of us were there, none of us can really tell what they would have all been drinking on that first Thanksgiving. So just drink what you like, not what you think you should like.