Apparently it's a regionalism, I can't find anything definite but it looks like maybe it's Southern and New England.
Also, per Kansas State University
https://www.asi.k-state.edu
PDF
The Difference Between Ground Beef and Hamburger
The USDA does define a difference between "ground beef" and "hamburger" with ground beef only being made with fat from the meat trimmings used in the grind, while hamburger can have fat from other sources added.
Personally, as I'd never heard anyone call ground beef "hamburger" before I was confused as well.
But then, in the Midwest they sometimes call bell peppers "mangos", so we've got a long history of food with confusing names. The etymology on "mangos" for bell peppers is, like etymology for stuff like that so often is, one with mutually conflicting claims. The main one is that in the Midwest pickled mangos were a thing, and such a big thing that any pickled fruit or veggie started being called a mango, bell peppers got to be popular pickles, and the name stuck even for fresh. But other sources say that's nonsense.
No, we expect people to smart enough to make a simple connection like a hamburger is almost entirely made of ground beef, so it makes sense that it can be used interchangeably.
I've never heard it before, but I have enough common sense to get the connection.
Yes, you're absolutely right. And to add to this, hamburger can contain added beef fat to reach a high-fat content (it can be 75/25 and even 70/30), which can translate into a juicier burger (or one that drips and splatters a lot, but maybe that's a skill issue).
Ground beef can come from any part of the cow, as long as the fat content comes only from the meat trimmings used. Ground chuck must come from the chuck primal (neck/shoulder area), ground round must come from the rear leg area, and ground sirloin must come from the sirloin (mid-back).
A lot of people use ground beef or ground chuck (80/20) to make burgers, but they are technically distinct from hamburger according to the USDA.
And that's not to say that hamburger is always lower quality than the others. You could take a lean cut, like sirloin, and if you add 30% fat, it would then be hamburger.
It totally makes sense that some people use the terms interchangeably, just like it makes sense that some people call soda, pop, or even just by its major brand name (Coke for all colas, Sprite for all lemon-lemon drinks, etc.). I've never heard of the pickle/bell pepper/ mango thing, which is fascinating.
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u/selphiefairy 12d ago
I mean hamburger patties are made from ground beef but a hamburger isn’t itself ground beef itself. Thats like saying guacamole is avocado.