It has always been legal to incorporate hearts and tongues,
but for the last 40 years hamburger processors have heeded “policy memo 27”
which prohibited heart and tongue.
It’s not clear what has happened to tongues.
Ironically, hamburger makers don’t need to declare that
hearts are included in the mix, nor is there any limit on heart content.
But there is a requirement that if more than 25 per cent of
the mix is cheek meat, it needs to be declared on the label.