Why YSK: When you cook meat, any water on the surface must first evaporate before much browning can occur. You want to get as much of a Maillard reaction as possible in the limited cooking time you have before the meat reaches the correct internal temperature. Removing the moisture first means that the heat of the cooking surface isn’t wasted on evaporation and can instead interact with the meat to form the complex sugars and proteins of the Maillard reaction.
To a degree yes. Moisture in general will limit browning. Fresh ground beef is usually dry enough. Frozen and defrosted ground beefwill have ice/water. Patting it dry with a paper towel takes care of this.
Ground turkey in particular is super wet all the way through so paper towels won’t really be able to get it all. To brown ground turkey, you put a big patty on the grill and don’t break it up, then wait for several minutes. This allows the surface to evaporate the water and then begin browning. If you break it open it will release the water inside the big ball of meat and it’ll take forever to evaporate enough for browning to start. You break it open later on after you’ve browned top and bottom.