A sandwich cut horizontally is blasphemy, plain and simple

When it comes to most things food-related, I subscribe to the “do you” philosophy. That is, like Sheryl Crow once said, “if it makes you happy, it can’t be that bad.” So I’m generally not about yucking anyone’s yum or issuing edicts. Pineapple on pizza? Sure, why not? Is a hot dog a sandwich? Eh, I don’t care!

But there are a few absolute, ironclad rules that I think protect us from losing our tenuous hold on civilization and sliding into the chaotic abyss, and one of them is this: Sandwiches must be cut in half on the diagonal. End of story. Not everyone, though, obeys this law, and this weekend we were confronted with the upsetting reality that there are monsters in our midst.

The revelation came in an Instagram post by Deb Perelman, a cookbook author who writes the popular blog Smitten Kitchen. On Saturday, she shared a video showing how to make a roasted-tomato soup and a grilled cheese sandwich – a truly stellar combination that felt just right for the early-fall chill out there. Her soup – shallots burbling in butter along with tomatoes brick-red from the oven, all blended together with a spot of cream – looked amazing (her food always looks amazing), and the sandwich was toasty-golden perfection. And then … like a screech on a record player (or whatever the modern equivalent of that sound is), Perelman took the video in a very, very dark direction. She cut the sandwich … horizontally.

Perhaps people wouldn’t have gotten so unhinged if she had merely bisected it vertically, the way some people (who are wrong but possibly not deserving of being cast out of society) might do. But her cut went across the poor sandwich’s equator. “My soul gasped,” wrote one. “My brain screamed,” said another. “Clearly you are a monster.” In hundreds of comments, people were rightly offended by Perelman’s crimes not just against sandwichdom but against humanity itself.

The superiority of a diagonal slice is undisputed. First, it’s pleasing to the eye. There’s something about a diagonal cut that elevates a humble sandwich into something more elegant. I grew up with vertical cuts, and now that I’m the one wielding the knife, that corner-to-corner slash makes me feel pretty freaking fancy, and that’s even before I sprinkle a few flakes of Maldon salt on my grilled cheeses. It’s also about functionality: It creates triangular halves with points that are perfect for dipping, which is especially important for a grilled cheese served alongside a steaming bowl of tomato soup.

My colleague Aaron Hutcherson, who develops recipes and writes for Voraciously, offered another practical explanation for the diagonal bias. “Grilled cheeses, and hot sandwiches in general, are best cut diagonally because it allows for the corners to cool to a non-mouth-burning temperature quicker,” he says. “It shortens the taunting from having a freshly made grilled cheese right in front of you that you can’t – or at least shouldn’t – shovel in your mouth from what feels like an eternity to something (slightly) more manageable.”

And this is not just our (correct) opinion – it’s science! A diagonal cut maximizes the number of bites with the least crust, as demonstrated in a breakdown from Popular Mechanics, with a mathematical formula that proved it.

Perelman took delight in the reaction, polling viewers on their preferred slicing style, and sharing that she had learned the technique from her mom – and that her husband also is a horizontal sandwich-cutter. In an interview on Monday, she told me she was enjoying the strong stances and musings from her readers, which were almost unanimously good-natured even when they questioned whether she was, in fact, an alien posing as a human. “The comments are such a riot,” she said. “And I get it. Sandwiches are so primal, so when it’s wrong, it’s very wrong.”

She’s heard from readers suggesting that her way of cutting sandwiches might be more common in Ireland, and that Germans often don’t cut their sandwiches at all.

In all her years of food blogging and cookbook writing, she says, she had not realized that her way of doing things was so unorthodox – or controversial. And she offered her own defense of her style. Perelman says that no matter the shape of the bread she’s cutting, she always makes the shortest cut, which she says preserves the structural integrity of the sandwich. “Whatever the shorter way is what makes sense to me, because wherever you make a cut, the stuff inside can fall out.”

And rather than changing her methods, Perelman says she’s going to keep right on, thank you very much, though a little more self-consciously: “I’m just going to have a complex about it now.”