Two roads diverge when you dig into the ancestry of Philadelphia's signature soup, which would be snapper, the sightings of pepper pot - the other old favorite - so meager these days as to disqualify it as a contender.
One path snapper soup took was that of the heavy roux base, that is, butter and flour stirred until a mahogany paste ensues. The other was that of a brothier soup, distinctively seasoned, but reliant more on its contents, its diced meats and vegetables, for its body and texture.
Needless to say, the thick, almost black-bean-dark gravy style won the evolutionary race. And it is this version, served with a cruet of sherry and Trenton oyster crackers to crumble (by crushing two of them together) on top, that you are likely to find in establishments that still serve the iconic stuff.
Quality control is exceedingly variable. But you can still find a proper bowl - redolent of sherry, clove and allspice - here and there.
Bucks County's old Pineville Tavern, south of New Hope, has a musky offering. The Union League has fielded a fine specimen. Old Original Bookbinder's serves a nicely balanced version, though you can keep its canned impostor. And on the right day, the Sansom Street Oyster House does a good job. On the wrong day, the soup has lost too much moisture, turning it from hearty to unappealingly gloppy.
It's that tendency toward overthickened gloppiness that's the Achilles' heel of the roux-based branch of the snapper family tree: too much gravy. No snap.
So it is refreshing to encounter a surviving rendition of the lost tribe - the brothier, lighter-bodied, vaguely tomato-based relative.
On irregular occasion, chef Fritz Blank, now retired from Deux Cheminees, would prepare such a version from a remembrance of the snapping turtle soup his German mother prepared for the taverns of greater Pennsauken.
But I've recently discovered a more reliable source (an open secret for years in Fox Chase) at Rieker's Prime Meats, the German butcher shop known for its unparalleled line of mettwurst and raviolilike maultaschen, wieners and imported sauerkraut. The crawl on the electronic sign in the parking lot says "Try Marcus' Famous Snapper Soup!"
I already had (they carry it at the Dutch Country Meats counter in the Reading Terminal Market), which was why I'd come. It is an amber-colored soup, a touch of acidity brightening it, the seasoning traditional, the sherry front and center - the flavor neither fish nor fowl, but slightly mysterious.
