Should you season the meat of a patty before or after it's formed? I've heard that it allows for more flavour if you were to add salt and pepper from the start, but I'm told doing that will cause the patty to fall apart more likely into just ground beef and that you should always season it AFTER the patty is formed.
How soon are you going to be cooking it after forming it? If you're not making it days ahead of time, it's generally not a problem.– JoeApr 18, 2018 at 0:39
Just a general question, I was forming patties for lunch with friends today and wasn't sure because I had seen it both ways in the past. Typically people that season when forming say you can do either but those that season after forming say never to season it before it's formed so I was curious if there was a reasoning for it. the sausage texture that Kenji said makes a lot of sense.– Jade SoApr 18, 2018 at 3:09
I like to pre-mix, and diced onions/peppers are about the only seasoning i would avoid without additional binders like breadcrumbs or egg.– dandavisApr 19, 2018 at 3:05
Kenji Lopez-Alt wrote about this issue on the website, Serious Eats. Salting the meat before making the patty does not cause it to fall apart, rather it creates a more bouncy, sausage-like texture. His conclusion is that most people prefer a patty that has a loose, open structure. His advice is to salt immediately before cooking.
I won't talk about salt as I cannot add to @moscafj's answer. However, pepper needs to be mentioned because it is different than salt. Pepper tends to get bitter under direct high heat, so it should be either mixed in before forming or added just after cooking. When mixed in the meat will protect the pepper from being torched, if you pepper right after cooking the residual heat and the fats will extract good pepper flavor.