I don't agree with the lady in the video. Most steaks and chops the grain is going from top of the flat surface to the bottom. All major steaks come from a long muscle, i.e. an uncut fillet of beef, or ribeye, strip etc. A sirloin, however, has several muscles but they are mostly in the same direction. When butcher cuts them for steaks(or you do it at home), you always cut your steaks against the long grain, or else they would be chewy. Now, what you were looking at in the video looking at the top of a cut steak, you were looking at the ends of the muscle fibers where they were cut across the grain, and seeing other patterns separating the muscle groups. That is not the grain of the major muscle group. The grain is the length of the muscle from where it is connected, to where it connects at the other end. Consider that a thin steak is more tender than a thick steak because the fibers from top to bottom are shorter. If the grain is across the flat surface, then a thinner steak would still be tough and chewy. I submit that the nice lady in the video does not know basic butchery and should not be lecturing. Note the piece she cut as "with the grain" was almost raw compared to the piece she cut "against the grain". Yes there are some variations in toughness in a cut steak, but that is due to interconnecting tissues or sinew in that area. Perhaps we could call what she demonstrated as "secondary" grain patterns which I could begrudgingly accept.
PS, if those steaks came from Costco, all but fillet (which she did not have)have been blade tenderized as rule, creating all kinds of phony patterns on the surface. Check it out.
