Why do my burgers puff up when I grill them, I do put an indent in the center
What are the ingredients in your burgers? how are they mixed and shaped?
A possible cause could be that the meat became too compacted/compressed while forming the burger, so that even the indentation trick doesn't work?
Cook's magazine had a good article on this recently -- it has to do with the outside cooking first. Most of us compound the problem by "mounding" our meat, which makes the outside thinner/cooks quicker/shrinks first. Sounds like you did the right thing to compensate -- putting an indent in the center -- maybe a bigger indent next time?
Oh (and I know this from watching way too much "Diners, Dives and Drive-Ins" where cooking burgers features regularly), on the grills of restaurants, they place a heavy, flat, weight on top to keep the burgers from shrinking up. Maybe try that (even a cookie sheet with a brick on it might work)?
That will make the burgers dry. Never put weight on it. Never mind DDD.
I make mine very loosely and put indent in center with my thumb. They come out fine.
More burger advice: DON'T FLIP the burger patty! Turn it once and only once. Thats all it needs. Amateurs feel compelled to turn it constantly. You are killing it. Personally I don't mind a "puffy" burger.
I honestly haven't noticed puffiness much (I speak only as an amateur, not a world-class burger professional ;) But in general, I find burgers cook more evenly when the meat isn't ice cold from the fridge when it hits the grill. Maybe this will reduce puffiness too...
So I guess, don't grill them with too much direct heat, instead slow and steady.
Alton Brown's Burger of the Gods, is a great technique for burgers. You can see the video on YouTube. Grind it yourself, and one turn only. The best burger.
The fliping burger thing is kinda weird. I've always used the one flip tech. But objectively there's no real reason not flip again and again. Here's the science.
I knew it would be Kenji! Personally I use the smash technique: http://www.thepauperedchef.com/2008/12/the-smash-technique-and-skinny-burger-perfection.html, but that's not so appropriate for a grill rack.
I was wondering literally yesterday if I'd get better burgers from flipping repeatedly (like a steak - controversial I know, but Science) or from a single flip. Sounds like an experiment is needed.
I think you're better off to make sure your sides are just as thick as the middle of the burger and then dimple. The dimple will only help so much. I know several burger joints with fantastic burgers who use a grill press to cook with. The thing is, that press is heated, it's sitting on the grill, so it essentially is cooking the burger from both sides to speed the process so they can do higher volume. So remember to heat your press before you put it on the burgers. I would not use a baking sheet and a brick. I would probably use something cast iron or buy a burger/bacon press. I got one for $20, works like a charm for lots of things.
Now if I could only buy Waffle House hashbrowns by the gallon tub...
This is how I shape burgers which might help: After dividing the seasoned meat into the correct number of portions, I form each ball into an overly large thin disc. Then I "thicken" the edges by pressing my right thumb against the edge as I shift/rotate the disc (while holding the disc in my left palm). This makes the patty smaller, getting it back to the right size, with a large thin center and thick edges.