Meatball recipes often urge caution: Overmixing, or, heaven forbid, kneading the meat will make the meatballs firm and chewy. That's true when it comes to delicate Italian meatballs, but Swedish meatballs are supposed to have a springy bite to them.
To achieve that light spring in our recipe, we use a stand mixer to give the meat a thorough, high-speed mixing. Muscle meat contains a water-soluble structural protein called myosin that's naturally bound in a complex with other proteins. Extended manipulation of ground meat causes myosin to dissolve out of the protein complex, distribute throughout the grind, and form a gel that binds the whole thing together.
The more extensive the mixing, the more myosin links together, and the more gel is created. Cooking the meat then makes the gel tight and strong. When you bite into it, the protein holds together until it suddenly yields all at once in a snappy burst of juice. (In sausage-making, where snap and cohesion are essential, the meat is manipulated even more.)
We use a similar technique when making lion's-head meatballs, which are also prized for a firm rather than tender texture.
So the next time you want meatballs with spring, don't hold back on the mixing. Better yet, pull out your stand mixer.
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