The porterhouse steak is, in my opinion, the ultimate cut of beef. The porterhouse has a strip steak on one side of the center bone, and a tenderloin steak on the other. This cut offers a much larger tenderloin than its cousin, the t-bone. The steak should be marbled (threads of fat); this fat in the meat will help keep the steak juicy and add natural flavor. I like to grill a thick cut (1 ½” to 2”) and slice and serve it family style.
There are countless rubs and marinades you can use to flavor your steaks. However, for this article, I want to emphasize how simple grilling and dressing techniques can result in the juiciest and flavorful steak you’ve ever grilled.
1) Prepare your porterhouse steak for grilling
A thick porterhouse needs to come to room temperature before grilling. A lot of people don’t like leaving meat out of the refrigerator, but this is a crucial step. Lightly oil the entire steak with vegetable oil. Crush a garlic clove with the side of a knife and rub it liberally over the steak. Finally, coat the porterhouse with a generous amount of coarse or kosher salt. A lot of the salt will fall off during grilling, so don’t skimp. Also, the salt will draw a little moisture from the exterior of the meat, helping to form a dark crust during grilling. Wrap the porterhouse tightly with plastic wrap and store it in a cool dark corner of your kitchen for at least two hours.
2) Prepping your grill
Whether you have a gas or charcoal grill you need to prepare two temperature zones. The first zone should be blazing hot. On a gas grill that means all of your burners are on high until you put the steak on, and then you will turn off half of the burners (one or two depending on the number of burners your grill has) to create a cooler zone for use in a few minutes.
Make sure you center the steak on the burners you plan on keeping lit. If using a charcoal grill set up your coals to cover half of your grill. This section should be at least two coals deep. This will create plenty of heat for searing and forming a nice crust on your steak.
Another benefit of cranking the heat in your grill like this is you will burn off any bits of food from previous grill sessions. Just in case, give the grill grate a quick cleaning with a grill brush. I would recommend wearing a grill glove at this point because of the high heat in the grill.
The last step before placing your steak on the grill is to lubricate your grill grate. A great trick for doing this is to cut off the little piece of fat at the bottom tip of the strip steak. Using grill tongs, rub the grill grate with this piece of fat to create a flavorful, non-stick surface for your steak. Alternatively, you can use vegetable oil, but I much prefer rendering the fat off the steak itself.
3) Grilling a porterhouse steak
When you are ready to place your steak on the grill, imagine a clock face. Place the top of your steak at the 10 o’clock position over the high heat section of your grill. Gently press down the steak to make sure its entire surface is in contact with the grill grates. Close the grill cover. If using a gas grill, now is the time to turn off a burner or two to create a cool zone. Make sure this cool zone is as far away from the steak as your grill will allow.
After three minutes, it is time to rotate the steak to create crosshatch marks. Using grill tongs, rotate the steak so its top is now at the two o’clock position. Close the grill for another three minutes. Flip the steak and position it pointing at the ten o’clock position. Just like the first side, grill for three minutes, rotate it to the two o’clock position, and cook for an additional three minutes with the grill cover closed.
4) How to test a porterhouse steak for doneness
Now it’s time to get our steak over to the cooler section of the grill. This is where we will finish cooking the steak until it is at the desired doneness. For a beautiful porterhouse, I highly recommend not cooking past medium doneness (about 145°F). Traditionally, a porterhouse is cooked to rare or medium-rare.
Move the steak with tongs to the cooler portion of the grill. Give it a quick poke with your finger. If it feels springy, you are probably close to taking it off the grill. If it still feels loose (like raw steak) then you will need to continue to cook the steak for an additional five to ten minutes.
You can check the meat with an instant-read thermometer by inserting it from the side of the meat into the thickest part of the steak (without touching the bone). Please remember that the temperature will increase by about ten degrees after we take the steak off the grill to rest. If you are looking for medium doneness (145°F) then you want to take the steak off when it registers 135°F.
I don’t recommend an instant-read thermometer for checking the doneness for two reasons. First, grilled steak is safe to eat at any temperature, so you don’t have to be scientifically accurate. Second, any puncturing of the meat is going to let out precious juices that I would rather keep in the steak until I’m ready to carve.
I recommend the poke test; with a little bit of grilling experience this quick check will result in the same doneness accuracy as a thermometer. I’ve seen a lot of tricks for determining the doneness of a steak by its firmness. Some people use the muscle between their thumb and first finger as a guide. Some use their palms as a guide. Here is my best advice: Remember what the steak felt like when you were rubbing it with the garlic and oil and salt. That is what a raw steak feels like. Now, think about shoe leather. This is what a medium-well steak feels like. In between, you have all the varying degrees of doneness. A rare steak will feel much like a raw steak. A medium-rare steak will have a little firmness to it. A medium steak will have firmness and bounce back when pressed with your finger and so on.
5) Take the steak off the grill to rest
When the steak has achieved the perfect doneness, it is time to let the steak rest for 10 minutes or more. I like to transfer it to a shallow dish containing a little extra virgin olive oil, fresh garlic and herbs. My personal favorite is a few sprigs of fresh thyme, a sprig of rosemary, a bay leaf and one crushed garlic clove. Lay the steaks on the oil and herbs and cover tightly with a sheet of heavy duty aluminum foil or a doubled sheet of regular aluminum foil.
The goal is not to rush the food to the table, but rather, let the steak redistribute all of its precious juices. When the steak hit the hot grill, all of the juices rushed to the middle of the meat. Now it’s time to let the juices return to perimeter of the steak.
6) Cutting and serving a porterhouse steak family style
After 10 minutes, transfer the porterhouse to a cutting board (preferably one with channels designed to catch the juice from the steak). I like to cut the strip steak and tenderloin steak off the bone in one large piece each. Then I like to cut each steak into ½” strips, being careful to keep the strips arranged in their original shape. I then return the cut steaks back to the bone and transfer to the serving platter.
This way your guests will know which pieces of meat are from the strip steak and which are from the tenderloin. Finally, stir any juices from the cutting board and the resting platter together and pour over the steak. Bring to the table and enjoy!