It's the end of the bottom sirloin. They call it "triangle roast" in the midwest and parts of the south. Not sure what they call it in Virginia. The UPC number is 1429 and IMPS/NAMP code is 185C. That'll impress the hell out of your butcher.
There are only two tri tips on a carcass. Not enough to display in a case. Butchers didn't know how to market them and threw them in the grindings or the cubes.
Tri-tip is naturally tender when cooked and carved right. Choice is almost as good as Prime, but Select is problematic. Black Angus, as always, adds another very pleasant dimension. It is a steak, not a brisket. Go ahead and trim the fat all the way off. It will come off easily without taking any meat with it.
I hate the whole "Santa Maria" name thing. I spent my early childhood around there a couple of valleys to the south -- the Lompoc and Santa Ynez valleys. I can tell you there's nothing they were doing in Santa Maria they weren't doing in the other central coastal valleys. Also, "tri-tip" was not discovered in Santa Maria in the fifties. I don't care how often it's posted on the internet. It was in the coastal valleys during WWII, and probably before too. If nothing else though, the shortages of the forties made it worthwhile to put everything in the display case. After the war, wholesale slaughter operations changed the way meat was packed and shipped in the west.
The Sunset Magazine article that garbled the discovery story had a lot more to do with making it popular throughout the west than anything that ever happened in Santa Maria. Thank you for letting me get THAT off my chest.
It's the perfect meat for that "Santa Maria" style grill you have. The preferred fuel is oak. Live oak is better than red oak, and red oak better than white oak, and white oak better than any other wood, and wood better than charcoal, and lump better than briquette and now we're into familiar territory.
After you trim, marinate iit in a couple of tbs each red wine and worcestershire sauce. If you're an anarchist hippy you could add a tbs of EVOO. If you're a total right winger, substitute bourbon for thw wine. Whatever. Keep the total volume of liquid down, you want to moisten the surface, not drown the steak.
Turn every 10 minutes. After 20 mintures the marinade will thicken into a syrup -- which is what you want. You can pour off the excess marinade and rub or continue marinating for as long as over night if you want penetration. The syrup that stays with the surface of the meat will make an excellent base for the rub.
Rub generously with the following blend:
4 tbs Morton kosher salt or 6 tbs Diamond kosher salt
2 tbs California (mild) chili powder, or 1-1/2 tbs mild and 1 tsp hot paprika
1-1/2 tbs freshly cracked black pepper
1 tbs granulated onion powder
1 tbs granulated garlic
1/2 tsp white pepper
1/2 tsp sage
1/2 tsp thyme
NO GODDAMN SUGAR
You want hot coals and a fair amount of distance between the cooking grate and the coals. You're looking for a grill temp just below 500, which is just below max on a decent home stove broiler. This method and temperature splits the difference between smoking and grilling.
Never cook tri-tip beyond medium rare, or I'll fly over to Virginia and shoot you myself. I mean really. Have some respect. Allow a 7 to 12 minute rest. Do not rest too long, or the steak will not only be cold it will lose it's texture. For God's sake, no 45 minute holds in a dry cooler, either.
Always carve across the grain or the meat will be tough. However, carved against the grain the meat is tender and not nearly as dense as brisket flat. Consequently you don't need to carve quite as thin. 1/2" to 3/4" is fine.
Tri-tip is the most flavorful of all of the steak cuts, with the possible exception of "flat iron." Side as you like, but the traditional Santa Ynez Valley sides are pinquito or pinto beans de la olla (not refried), Danish cucumber salad (go figure!), and sourdough bread. A real-deal Caesar salad is a nice touch.
Sauce as you like, but I recommend staying away from anything too sweet. I make a traditional bordelaize which I enrich with a little ketchup and worcestershire so it's more cue-esque. I don't know why I mentioned it, what are the odds?
Salsas are very good instead of sauces. If Herdez Salsa Verde in the can (the bottled is different) is available to you, it's damn near perfect. Otherwise make a pico de gallo (in French, a mignonette). If only a "barbecue" sauce will do, mix 1/2 cup Homade Chili Sauce (little round bottle) with 2 tbs worcestershire sauce and 2 tbs balsamic vinegar, and add a tsp of Tabasco Chipotle. That'll do 'er.
Merlots, especially affordable Merlots, are too soft and lack sufficient character for beef this intense. You can partner this with as big a wine as you like such as Pinot or Cab, but a decent Zinfandel or a blend built around Zin like "Big House Red" or "?" (a lot of Barbera in that one) won't break the bank. If you're sick and tired of all the Californicating around this cut you could try a Shiraz or a Rioja.
FWIW, the best part of the top sirloin (top block) can be cut to the same thickness (more than 2", less than 3"), then prepared and cooked in the same way. Indeed, it is the traditionally preferred cut for this kind of barbecue. Tri-tip came into its own during the meat rationing of WWII. Top has slightly less flavor, but is a bit more tender than tri. There aren't any rules about carving a top, because top doesn't have a grain. The intelligent choice is to use the cheaper.
There are a million ways to skin a cat, no doubt. This is one of the very best ways to cook a tri.
Rich