There is no organized program to taste beers from each of the World Showcase countries at Epcot. However, many, many Disney guests have undertaken this "Drink Around the World" tour on their own. You can read a bit more about this
HERE,
HERE, and
HERE.
If you are looking for a smaller experience than this, you should know that there are tasting flights of beer available in the UK and Germany pavilions at Epcot. These are groups of locals beers available in sample portions.
I have a Rose & Crown (UK) menu in front of me. The "Imperial Sampler"
can include tastes from the following: Bass Ale, Boddingtons English
Pub Ale, Harp Lager, Stella Artois, Strongbow Cider, and Guinness
Stout. I have to add that I had my number one favorite WDW drink a few
months ago at the Rose & Crown. This was the "Cider and Black,"
which is the Strongbow Cider with a shot of Black Currant Cassis.
Delicious! And very refreshing on a warm day.
The Biergarten (Germany) sampler flight includes Beck's, Beck's Dark, Franziskaner Hefe-Weisse, and Spaten
Optimator.
Enjoy your time at Epcot :-)