How is it checked?
After meat and poultry are inspected for wholesomeness, producers and processors may request that they have products graded for quality by a licensed Federal grader. The USDA’s Agricultural Marketing Service (http://www.ams.usda.gov) is the agency responsible for grading meat and poultry. Those who request grading must pay for the service. Grading for quality means the evaluation of traits related to tenderness, juiciness, and flavor of meat; and, for poultry, a normal shape that is fully fleshed and meaty and free of defects.
USDA grades are based on nationally uniform Federal standards of quality. No matter where or when a consumer purchases graded meat or poultry, it must have met the same grade criteria. The grade is stamped on the carcass or side of beef and is usually not visible on retail cuts. However, retail packages of beef, as well as poultry, will show the U.S. grade mark if they have been officially graded.
The grade symbol and wording are no longer copyrighted; however, according to the Truth in Labeling Law, it is illegal to mislead or misrepresent the shield or wording.
So some dude looks at the color and decides? Why call it ‘85%’ then, and not ‘kinda white’.
Isn’t ground beef, sold in the manner you describe (with percentages) quite literally a mixture of meat at a factory, where they would certainly know the content of lean beef and fat (which is typically ground chuck)?
It’s not like they’re using that metric to grade a piece of meat carved directly off a cow - ground beef is a processed product “mixed” at a processing plant, I assume, and the processing plant can control the ratios of what goes into the mixture.
I asked my uncle, who is a retired butcher. He said he would always start with very lean beef, weigh it and then add beef fat to get the ratio where he wanted it. He owned a local butcher shop for forty years and did not pay for USDA grading. He doesn’t know if the government had some special formula for doing it.
A ground beef fat analyzer for industrial production.
A good eye from a butcher using trimmings
An assumed value for a butcher grinding primal cuts
If nothing else, it’d be very easy to determine from the density.
Hard to get all the air out of a given lump of ground beef for a repeatable density measurement.
Would the conductivity change based on the fat percentage or anything like that?
This has always been my understanding of the process. A huge number of grocery stores process their own ground beef in store. Butchers mix beef fat into lean cuts to get the desired percentage.
My hunter friends make venison sausage every year. In their case they get pork fat from the grocery store to grind in with the venison to make sausage, as venison alone is far to lean to make sausage by itself.
In high school, I worked at a local A&P grocery store and was talking to one on the butchers in the meat department as he was removing ground beef from the display case. As you know, ground beef turns grey after extended exposure to oxygen and he was removing those packages. He dumped the contents into the meat grinder and added two cow tongues because of their high blood content and after regrinding, the meat was red again and ready for sale.
I wouldn’t trust any of the claimed fat content on ground beef but I’m good with that since I don’t eat it.