What Internal Temperature to Cook Beef Tenderloin for Perfect Results

Cooking beef tenderloin can seem daunting. It’s an expensive cut of meat that you don’t want to overcook. Getting the internal temperature just right ensures you end up with a tender, juicy and flavorful roast. This guide will walk you through everything you need to know about achieving tenderloin perfection.

Why Pay Attention to Internal Temperature?

With beef tenderloin, perhaps more than any other cut of meat, internal temperature matters Taking the time to monitor it as the beef cooks means the difference between a sublime tenderloin and an overcooked disappointment.

While cooking times can provide a rough estimate, they can vary substantially depending on the size and shape of the roast, your oven, and other factors. The only way to be sure your expensive tenderloin turns out right is to use a good digital meat thermometer.

What Is the Best Internal Temperature for Beef Tenderloin?

For most people, the ideal doneness for beef tenderloin is medium-rare, which means an internal temperature of 130-135°F At this stage, the center is bright pink while the outer portion is light pink The meat is juicy and tender with a warm red center.

Here are guidelines for different levels of doneness:

• Rare – 120-125°F – Bright red center, cooler temperature
• Medium Rare – 130-135°F – Warm red center, juicy and tender
• Medium – 140-145°F – Pink center, firmer texture
• Medium Well – 150-155°F – Trace of pink, drier meat
• Well Done – 160°F+ – No pink, flaky, dry texture

Keep in mind that the tenderloin will continue cooking after you remove it from the oven or grill, rising about 5-10° more degrees. So take it out slightly under your ideal temp.

The USDA recommends cooking tenderloin to at least 145°F for food safety. While you can certainly go this high or higher if you prefer meat more well done, be aware it will be less juicy and tender.

Tips for Measuring Internal Temperature of Tenderloin

Use an instant-read digital thermometer for the most accurate readings. Less expensive analog models can be off by 5-10 degrees.

For whole tenderloin roasts, insert the thermometer into the thickest part of the meat, avoiding bone. Move it around to check the temp in a few spots.

For individual steaks or filets, insert the thermometer sideways through the center.

Let the thermometer fully register before noting the temp – it takes 15-20 seconds.

Double check a few areas to confirm even cooking.

For very thin cuts like filet mignon steaks under 1 inch thick, use tongs to hold the meat while taking the temperature. This prevents overcooking from leaving the thermometer in too long.

Factors That Affect Tenderloin Internal Temp

A few key factors impact how quickly a tenderloin roast reaches the target internal temperature:

1. Thickness – A whole tenderloin roast cooks slower than thinner filet mignon steaks. Allow extra time for thick roasts.

2. Bone-In vs Boneless – Bone-in roasts conduct heat slower than boneless. Cook bone-in roasts 5°F higher final temperature.

3. Cooking Method – High heat methods like grilling or broiling cook faster than moderate oven roasting. Adjust time accordingly.

4. Starting Temperature – Meat right from the fridge takes longer to cook than meat at room temp. Let meat sit out 20-30 minutes before cooking.

5. Seasonings and Rub – Ingredients like salt, seasoned salts, and sugary rubs accelerate browning. Keep an eye on heavily seasoned meats.

How Long to Cook Beef Tenderloin

Cooking times for tenderloin vary substantially based on size, thickness, bone-in vs boneless, and doneness level.

Here are some general time guidelines:

• Whole tenderloin roast – 1 1/2 to 3 lbs. Cook 25-45 minutes at 400°F for medium-rare. Up to 60 minutes for well done.

• Tenderloin steaks – 1-2 inches thick. Grill or pan sear 4-8 minutes per side.

• Filet mignon – 1-2 inches thick. Grill or pan sear 4-8 minutes per side.

• Small tenderloin filets – 1/2 inch thick. Grill or pan sear 2-4 minutes per side.

The only way to be sure beef tenderloin is cooked properly is to use an instant read thermometer. Rely on temperature, not times.

Resting and Carryover Cooking

Once removed from the heat source, the tenderloin will continue to cook 5-10°F higher as the heat distributes through the meat. This carryover cooking is why you should remove the roast or steak just shy of the final temp you want.

Rest the tenderloin at least 5 minutes tented loosely in foil before slicing and serving. The resting period allows juices to reabsorb for maximum tenderness and moisture.

Mimic the Steakhouse

One technique used by high-end steakhouses and experienced cooks is to roast the tenderloin at a low temperature, then finish it with a hot sear.

Cook the meat in a low 250°F oven until it reaches 15-20°F under your desired final doneness. For medium-rare, cook to about 115°F.

Then, remove it from the oven and sear all sides in an extremely hot cast iron pan for 1-2 minutes per side. This helps develop a beautiful crust without overcooking the interior.

Finish by basting the meat with garlic herb butter as it rests before slicing.

Mastering the internal temperature for beef tenderloin may take some practice, but it’s worth the effort. Perfectly cooked tenderloin is sublime – tender, juicy, and packed with flavor. Invest in an accurate digital thermometer and refer to this guide for temperature benchmarks. In no time, you’ll be turning out restaurant-quality tenderloin at home.