Located on Beacon Street (in Somerville) about halfway between Porter Square and Inman Square (both in Cambridge), RF O'Sullivan and Son is a neighborhood bar that's become famous for its spheroid burgers that take 20 minutes to cook. The U-shaped bar shields the grill and has about a dozen hightop stools; the 2- and 4-tops around the perimeter can accommodate another 40. With such a tight arrangement, it can get crowded quickly at night. The walls are wood and stone. Sparsely placed decor elements include a few beer signs and framed magazines and other testimonials to their burger prowess.
Mention O'Sullivan's to any connoisseur of the burgerly arts who's patrolled the Boston beat for more than a decade and you're almost certain to get a strong reaction. Many love it, many hate it; few fall in between. Most of the disagreement revolves around the shape of the burger and the length of the cooking time.
This is a simple old school sesame seed bun, reasonably fresh. No bells, no whistles, no plus, no problem.
I went with the Cheddar and Onions burger that promises tangy onions. I was a little surprised by the annoying red sauce that looked like canned tomato soup, but the onions actually wound up being minor players. Ditto the thick robe of cheese, which added mostly texture and subliminal flavor.
I'm not sure of the ounceage, but picture a ground-in-house sirloin patty about the size of a billiard ball. It's grilled over a low flame and never messed with—pressing down on it with a spatula is strictly forbidden. The goal is either to prevent the juices from leaking out or to increase beer sales during the extended cooking time.
As for my Cheddar and Onion burger, the still-spherical patty fell a little short of my requested medium rare, coming in closer to rare with a barely cooked center. The exterior carried moderate crust and little to no seasoning. The interior achieved its goal perfectly, sealing in juices that ran freely. There was just enough grill flavor to accent the meat, avoiding that overbearing charcoal flavor you sometimes get with a grilled burger.
I liked the fineness and the finesse of the grind. And even though I prefer something more exotic, I enjoyed the understated simplicity of the beef, which had a slightly steaky feel.
I didn't like that the shape of the patty impacted not only the duration of the cook but the doneness too. I should note that my three previous visits (all undocumented and all at least five years earlier, including a weekday lunch and two Saturday nights) had no doneness issues. Another byproduct of the shape is its inability to reach the perimeter of the bun, virtually assuring that every bite will have either too much bun or too much meat.
For me, these are minor issues, not deal breakers, but they certainly don't build a case for O' Sullivan's as one of the best burgers in Boston.
The Fries (and such)
You have a choice of fries, onion rings or half and half, so I opted for variety and went with both.
Onion rings: Big, thick, puffy, beer battered, slightly sweet, slightly soggy and somewhat of a disappointment.
Fries: Far from traditional and far from a disappointment, these were wedges whose soft, warm interior gave them more of a baked potato feel. Go with the fries.
The Bottom Line
I'm one of the few who neither loves nor hates the O' Sullivan's burger. It doesn't crack my top 10 Boston burgers, and probably wouldn't make my top 20, but I still believe it's a relevant enough burger—and yes, a good enough burger—to recommend trying it at least once.
Other Opinion/ Info
Yelp reviews of RF O' Sullivan & Son
Urbanspoon reviews of RF O' Sullivan & Son
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