The perfect time to salt burgers
Salt should be added early to many meats, but not to burgers. Instead, you shouldn’t add salt to burgers until just before they go on the grill or in the pan.
Salting ground beef too early draws out the moisture resulting in a burger that lacks moisture (aka taste). It also causes the proteins to unravel and stick to each other, making the burger denser. Additionally, mixing salt into the ground beef causes you to handle the beef more than you should, compressing it into a sausage-like texture. The best burgers have a looser texture, where you can basically make out the different strands of ground beef.
By the way, timing matters even more than you think here. Even adding it a few minutes before it hits the heat has negative effects. Right before means right before.