Hock & trotter at 92 degrees: Eisbein · 264

Ankle and foot: skin, tendon and bone with very little muscle. Almost pure collagen, which is why it turns broths silky and why chilled versions set into jelly on their own. Germany roasts it, Korea braises it in soy and spices, and both end up somewhere gelatinous and addictive.

Pick hocks with unbroken skin and a clean cut through the bone; splintered ends cloud the broth. Done is when the skin yields to a spoon. Anything short of that and the collagen is still rubber rather than gel. Colour, sinew, where the fat sits, and thickness are what you check before you pay. Ask for the thickness that matches “Eisbein.” Use 92 degrees and 92 when you cook. Salt after you know the job. Do not play with undercooked meat.

At the counter, read the use on Hock & trotter before the photograph. 92 degrees is the internal heat, “Eisbein” is the dish, and 92 is the stage of the fire. Marbling alone does not split stew from grill. Sold for skin and collagen more than grade — joints should be evenly cut and skin unblemished.