Who first discovered that if you whip egg whites, they stiffen? It doesn’t seem like the sort of thing that would happen accidentally: oops, I accidentally separated an egg, and accidentally whipped the whites for 20 minutes, and look what happened!
Why would you separate an egg, if you didn’t know you could do this?
Why would you whip the whites forever if you didn’t know what happens?
Well the yolk and the white have different properties in baking so a person may separate the eggs simply because they don’t want the yellow color of the yolks affecting their dish or they’re using another binder and don’t need the whites. From there, I assume it didn’t take a lot of experimentation to realize that egg whites can be whipped and even whites not whipped to stiff peaks will still leaven a dish.
If you beat whites with a fork even a little, they start to froth. It wouldn’t take a large leap for someone to think: “What would happen if I really went at it?”
Likewise whipping cream. And then whipping it some more. And some more. And then, butter results. And that’s been a staple since before recorded history – IIRC, butter has been found preserved in bogs? Offering, or forgotten storage? Anyway, you can find “A Boke of Gode Cookery” all over the internet. People did much weirder things to food in the interest of “I wonder what happens if …”
I read somewhere that butter was discovered accidentally; someone was transporting milk on horseback and the jostling eventually turned the milk to butter. And as for beaten egg whites, I like to think that some apprentice somewhere was instructed to beat the egg whites but the boss forgot to tell the apprentice when to stop. So sometime later, the boss was asking, “What did you do!? Hey, this is kind of interesting. Let’s experiment with this.”
somehow they figured out it needed cream of tartar and vanilla too. Quite a bit of serendipity to create meringue for a pie.
cream of tartar occurs naturally in wine casks and on corks. So it was readily available.
Okay … so who was the first guy to think “Hmmm. I wonder what that bee goo tastes like?” :dubious: 
Probably someone who saw a bear eating it and wondered how it tasted.
What about caviar? Who looked at a sturgeon (weighing upwards of a ton) and decided that the small egg sac was where the good stuff was?
I’m unsure as to when, but it seems like it happened sometime between Rome and the Elizabethans, as I have used recipes that use beaten eggwhites (along with cream) from the mid- 1500s but there aren’t any Roman recipes that use that technique.
You don’t need either of those to make meringue. Just egg white and sugar.
Yeah, I’ve never used cream of tartar myself, but I hear it makes the whipping easier. Same with using a copper bowl,
Oh, and in case anyone didn’t know - the brine from canned chickpeas makes a surprisingly serviceable vegan eggwhite substitute in meringues, macarons etc.
Whoa. I’m not vegan myself, but that is seriously cool. I’ll have to try it some time.
The thing I find works really well is a really cold bowl. I’ve taken to putting the eggwhites in the freezer in their (steel) bowl for 10 minutes before beating them.