The Dark Meaning Behind The Phrase The Proof Is In The Pudding
One is a sweet treat called pudding, with a consistency that can only be described as "puddingy." The other is a common enough saying: "the proof is in the pudding," meaning something like the value or quality of something can only be judged through experience or by trying it. But what do those two things — actual pudding and that popular idiom — really mean, and what do they have to do with each other? Turns out, quite a lot. Once that question is answered, you'll never think of pudding the same way again.
These days, pudding is usually a cornstarch-thickened dessert made from fruit juice, flour, tapioca, and eggs, among other ingredients (per Betty Crocker). It's often sold as a boxed mix and served at holidays as a dessert. The pudding we eat today has actually changed quite a lot over the centuries, though, and so, too, has our most commonly-used definition of proof. The real meaning of the "proof is in the pudding" can be found in what pudding used to be, as well as that alternative meaning of the word "proof," per Merriam-Webster.
Proof doesn't always mean what you think it means
The first thing to consider is that "proof" has a definition somewhat less common than what most people think of, which is that something is incontrovertibly true, as in a court of law. Proof can also refer to a test, like when measuring alcohol content, as Merriam-Webster explains. In this other context, proof means something more like "test" than it means a confirmed fact.
Considering this alternate definition of proof certainly helps make sense of the saying "the proof is in the pudding." In this context, it means the only way to find out whether or not the pudding tastes good, or is even edible, is to try it (per Oxford Reference). Naturally, this applies to any number of scenarios that might be encountered in life, and goes a long way today explaining why "the proof is in the pudding" is now such a popular saying. This only partially explains, though, how this idiom came about. The next point is to consider how pudding itself has changed over the centuries.
Pudding used to be pretty gross
The first known reference to quality proven through tasting, or value demonstrated by doing, shows up in the 14th century, although the idea wasn't expressed in quite the same way as it is now. It used to be longer, as in, "the proof of the pudding is in the eating," or sometimes "tasting," per Merriam-Webster. The first pudding-proof connection specifically showed up in a saying a few hundred years later, in the 17th century. Variations on the saying "the proof is in the pudding" can also be found in the writing of Jonathan Swift, and Alexander Hamilton, among others. The pudding back then was likely not the same kind of pudding your mother served you after you had your tonsils out, though.
The fact of the matter is, pudding hasn't always been a desirable, sweet, and tasty treat at all. Although savory puddings aren't entirely a thing of the past (via Martha Stewart), at one point, pudding could sometimes be more like a sausage, or a bunch of meat scraps and seasoning stuffed in animal intestines or stomachs. Sometimes there was actual animal blood in the mix, as is the case with blood pudding. Sounds nasty, right? In the days before refrigeration or health and safety standards, how could you make sure all those meaty bits weren't spoiled or, at the very least, were palatable enough to eat? Well, you tasted the pudding, according to Mental Floss. In this instance, the proof in the pudding could be a matter of life and death.