What makes a brisket tough? Sometimes it melts in the mouth, sometimes it’s hard and awful! Same recipe. Why?

Sweet and Savory Brisket
Recipe question for: Sweet and Savory Brisket


Nancy July 11, 2019
In general, and further to Lori T's point about the second cut (point or deckle):
Get to know if/when there are local specials and buy the second cut for the freezer (freezes well both raw and cooked).
Also, if you can buy from a live butcher (whether inside a grocery store or free-standing), you may be able to get better cuts or consistency than from packaged meat.
May. There is still the nature of the beast (sorry for the bun)...again, further to Lori's point, the cuts do vary because of the animals' history. Yes, cook low and slow, in advance of serving day.
Nancy July 11, 2019
"Sorry for the pun"
Lori T. July 11, 2019
Some of the trouble may also lie in the type of brisket cut you have. A whole brisket is composed of two layers. The upper layer is referred to as the point cut, sometimes also called a deckle cut,and it has a thicker layer of fat on top. The lower layer is the flat cut- but it's called a first cut, which has a thinner layer of fat on the top. These two cuts do cook differently, though both respond to low and slow. The marbling in both is sparse, but the upper cut has the most. Unfortunately that point cut is sometimes hard to find outside of St. Patrick's Day. Most of what you find in the stores labeled as brisket is a trimmed first cut, or flat cut. The recipe calls for a second cut- because it's most likely to tenderize in the braising time used. If you can't find a point or second cut, you can use the flat cut- but you will likely need to give it more time to tenderize. As HalfPint noted, some differences are due to the amount of work the muscle did in life- and you have no way to know that on the purchasing end. That's why when I plan a brisket dinner, I cook it the day before and refrigerate it until time to reheat. You aren't in a rush for it to finish, and can give it whatever time it needs that way. Plus, I've found a brisket cooked this way also slices nicer and easier.
HalfPint July 11, 2019
Here's what Cook's Illustrated says about why brisket is so tough: https://www.cooksillustrated.com/how_tos/11007-why-brisket-is-the-toughest-tough-cut

Basically, it comes down to cross-linked collagen which apparently softens but never breaks down to gelatin. You are getting so much variability with the same recipe because you're using a different brisket each time. The more exercise cattle has, the more cross-linked the collagen becomes, which is not great news. It's impossible to tell how much exercise any animal gets. You could try to cook the brisket longer, keeping the temperature quite low, to at least soften the collagen.
Recommended by Food52