It may not quite qualify or be called a session beer, but I'll be damned if English Porter doesn't drink like one. While not an alcoholic behemoth like Baltic Porter, and not leaning towards the hoppier end of things of an American Porter, it is usually my first choice in this old-world family of dark beers. Rich and malty, highly drinkable, and with moderate alcohol levels, there's a "satisfaction" factor that this style seems to deliver for me, and I almost always have a few in the fridge for whenever I get the craving for what I consider to be the perfect middle-of-the-road beer.
