For decades, patrons at Philadelphia’s seafood houses happily nibbled on crunchy, biscuit-like orbs known as oyster crackers, piling dabs of tangy horseradish on top. Often served in large glass goblets on the bars of oyster houses, the crackers were as much a part of the city’s fabric as soft pretzels.

But about a year and a half ago, owners of local establishments say, the cracker they knew began to crumble.

The shape morphed from spherical to rectangular, said Sam Mink, owner of the Oyster House at 1516 Sansom St. The taste changed and the texture was softer, like a regular cracker. It didn’t break into hard crumbs when cracked over soup.

Then, in the fall, the company that produced the crackers stopped making them, forcing businesses like Mink’s to scramble for a replacement. He ended up with Westminster Crackers, which are small, come wrapped in packets of 10 or so, and taste more like saltines.

“People went crazy,” Mink said. “They were just so upset. This has been the number-one topic at this restaurant for the past six months.”

Amazon and the cracker company’s website have been bombarded with scathing reviews from customers who aren’t pleased.

“Raised in the Philly burbs, OTC’s were a childhood staple," one wrote. “They have ruined that memory!...BOO!”

Philly’s original oyster crackers were first made in 1847 by a Trenton company founded by a British immigrant who sold them out of his wagon. During the Civil War, the company supplied crackers to the Union Army, according to the Smithsonian National Museum of American History. The company eventually was named OTC (for Original Trenton Cracker) and supplied seafood houses in Philadelphia, where patrons stirred them into oyster stews. The company moved to Lambertville in the 1970s.

“For at least 30 years, we used OTC,” said Dave Braunstein, co-owner of Pearl’s Oyster Bar in Reading Terminal Market. “People loved reaching into the jar; they’d grab a few."

But as ubiquitous as the crackers were here, they weren’t widely known beyond the region. A 1986 Inquirer article noted that 80 percent of OTC’s oyster crackers were consumed within a 120-mile radius of Philadelphia.

Local restaurateurs say the trouble started about two years ago, when the bakery responsible for making the crackers dropped them. OTC, now owned by Panorama Foods in Massachusetts, found another bakery. But according to a statement posted by president Ken Meyers on the company’s Facebook page in July 2018, the equipment that once churned out the crackers no longer meets safety standards.

“Recreating a custom machine of this sort is simply not possible for a small company such as Panorama Foods,” the statement reads. “Given that, the original shape is, likely, gone forever. That, however, is no reason not to continue to strive for a perfect match as regards taste and texture. We, and the new bakery are working, with each production run, to do just that but, clearly, some of you feel we haven’t crossed the finish line quite yet.”

Panorama did not return requests for comment.

Mink, a third-generation owner of the Oyster House, said OTC crackers and horseradish have been on the restaurant’s bar since the 1940s. There was a backlash after the shape and taste changed, but it was nothing compared to what ensued after the Oyster House started serving different crackers. Patrons try to dress nickel-size crackers with horseradish, making a mess. Every day, Mink said, someone asks to speak to the owner of the restaurant about the crackers. After hearing the explanation, some suggest the Oyster House make its own.

“You imagine a whole team of people rolling out dough, all for a product that’s a freebie,” Mink said. “I thought about it, of course.”

The Olde Bar, the restaurant that served OTC crackers for years when it was the Old Original Bookbinder’s, now uses another brand. Pearl’s has switched to Westminster.

OTC is making the crackers again, but fewer of them, and suppliers have given local restaurateurs no hope of getting any. The recipe is still being tweaked, if recent online comments are to be believed: (“My oyster stew was mediocre at best with the new crackers,” one said).

“These crackers have been such a big part of what we do," Mink said. “You sometimes don’t realize how passionate people are until you change something. But at the end of the day, it’s good that they’re passionate. It means that they care.”