Loin, Tonkatsu, 80°

Cook Loin as “Tonkatsu” until the centre reads 80 degrees. The mark to keep is 80°. Before you pay, check once that the cut named on the package matches the cut on the slip. If the seam of sinew is badly split, change the slip from a short sear to a long cook. Centre-cut loin should show a pale pink eye and a modest fat cap; excess purge means poor handling. At the butcher, open Loin so the slip shows 80° first, 80 next, and “Tonkatsu” beside them.

This week, before you enter the butcher, write the cut, the method, and the core temperature at the top of the shopping slip, and at home keep the heat until the thermometer shows that figure. If the grain is coarse, give more time at the same temperature, and do not time a thin slice and a chunk the same way. The order is Loin, 80°, 80, then “Tonkatsu”. When the thermometer is done, look again only at 80° for Loin and leave 80 on the slip.

Do not call the meat done from color alone, and do not read the temperature as a grade score. Check that the core temperature on the slip and the thermometer match, and do not kill the heat before that mark even if the color changes first. If the seam of sinew is badly split, change the slip from a short sear to a long cook. Match Tonkatsu with 80 at the butcher before you close 80° for Loin. Cook Loin as “Tonkatsu” until the centre reads 80 degrees. The mark to keep is 80°.