A Fat Cap is the white layer of fat on top of the meat.
The fat cap serves many purposes. It can add flavor to the meat during the BBQ process. It can help keep the meat tender while cooking. It can be used to protect the meat while over direct heat. And some people like to eat it.
For BBQ discussions we are usually referring to the fat cap on a pork butt/shoulder or brisket.
When trimming meat we like to leave about 1/4 inch of the fat cap on.
Some people will score the fat cap to allow the rub and juices to get down into the fat.
Fat Cap UP or DOWN When Cooking?
A big question about the fat cap is “should the fat cap be on top or bottom while cooking?”.
Some people put it down to protect the meat from burning while others swear by keeping it on top to help baste the meat. And some will start it up or down then flip it during the cook.
Just like many other BBQ topics, there are many opinions on this subject and we recommend trying it both ways and deciding for yourself.