1.5 Lb Pork Loin Recipe: Herb-Crusted Roast With Perfect Medium Rare Core

A 1.5 lb pork loin recipe that delivers a perfect medium-rare core with a crisp herb crust is what transforms weeknight dinners into restaurant-worthy meals. I developed this method after years of perfecting pork roasts for my restaurant, where precision matters most.

The secret lies in controlling the internal temperature while building flavor through a simple herb crust that locks in juices without drying out the meat.

This recipe focuses on simplicity—just a handful of ingredients that work together to create a tender, flavorful roast. The herb crust, made with fresh rosemary, thyme, and garlic, adds aromatic depth while keeping the cooking process straightforward.

Whether you're grilling or roasting, the technique ensures a juicy center with a beautifully caramelized exterior every time.

What you'll achieve is a pork loin that's perfectly cooked—medium-rare at the core with a golden, flavorful crust. The meat stays succulent and tender, with layers of herb-infused flavor that elevate any meal.

This method works equally well for special occasions or a simple family dinner, proving that great results don't require complicated techniques.

Pair it with roasted vegetables, a fresh salad, or mashed potatoes for a complete meal. The versatility of this recipe makes it adaptable to any table setting, while the foolproof method ensures success even for home cooks new to pork roasting.

Let's get started on creating a dish that will impress everyone at the table.

Ingredients for 1.5 lb pork loin

Precision-crafted ingredients for a restaurant-quality pork loin with flawless medium-rare perfection.

The pork loin is non-negotiable—center-cut, bone-in delivers the best balance of tenderness and flavor. Source from a trusted butcher or Whole Foods meat counter where they can trim excess fat for you. Look for bright red, marbled meat with minimal surface graying. If shopping at Costco, opt for the pre-trimmed loin to save time. The herb crust relies on fresh rosemary and thyme—avoid dried substitutes here as they lack the aromatic depth needed for this technique. For the garlic, peel and mince just before mixing to preserve its volatile oils.

No fresh rosemary? Fresh thyme with 1 tsp dried rosemary works in a pinch, though texture will differ. Substituting garlic powder for fresh loses significant flavor—minced jarred garlic is better than skipping it. The olive oil should be extra-virgin with a peppery finish—avoid light or refined oils. For the butter, European-style with 82% fat content creates a richer crust. If you prefer, ghee can replace butter for a dairy-free option without compromising texture. The crust mixture should be cohesive but not pasty—adjust with additional herbs if needed.

The pork loin keeps best in the coldest part of your fridge, wrapped in parchment paper for up to 3 days before cooking. Prep the herb crust up to 12 hours ahead and store in an airtight container. Once cooked, the roast reheats beautifully—warm in a 300°F oven for 10 minutes with a splash of water for moisture. For make-ahead meals, slice and freeze portions for up to 3 months. Always let the meat rest 10-15 minutes before slicing to preserve juices—this is non-negotiable for perfect results.

Step-by-step instructions for herb-crusted pork loin roast

This method delivers a perfectly balanced herb crust with a medium-rare core every time.

In a small mixing bowl, combine the 0.25 cup finely chopped fresh rosemary, 0.125 cup fresh thyme leaves, 6 minced garlic cloves, 0.5 tsp garlic powder, 0.25 tsp dried oregano, 1.5 tsp Diamond Crystal kosher salt, and 1 tsp freshly ground black pepper. Mix thoroughly to ensure even distribution of flavors throughout the crust.

Next, add the 2 tbsp cold cubed unsalted butter and 0.25 cup extra-virgin olive oil to the herb mixture. Use a fork to work the butter into the herbs until you achieve a coarse, sand-like texture. This ensures the crust will adhere properly to the pork loin while creating a flavorful barrier that locks in moisture during roasting.

Place the 1.5 lb center-cut pork loin on a clean cutting board and pat it dry with paper towels, removing any excess moisture from the surface. This step is crucial for achieving a crisp herb crust rather than a soggy one.

Generously coat the entire surface of the pork loin with the herb mixture, pressing it firmly into the meat so it adheres well. Once coated, transfer the pork to a plate and refrigerate uncovered for at least 1 hour or up to 4 hours. This resting period allows the flavors to penetrate the meat and the crust to set properly before roasting.

Preheat your oven to 375°F. Place a meat thermometer in the center of the pork loin to monitor the internal temperature accurately. Position the pork loin on a wire rack set inside a rimmed baking sheet to allow for even air circulation around all sides.

Roast the pork loin for 35-40 minutes, or until the internal temperature reaches 130°F for medium-rare. The crust should be golden brown and crisp, while the meat should remain tender and juicy. Avoid overcooking—pork continues to rise in temperature after removal from the oven due to carryover cooking.

Remove the pork loin from the oven and transfer it to a cutting board. Tent loosely with aluminum foil and let it rest for 15-20 minutes. This resting period is essential for redistributing the juices throughout the meat, ensuring each slice remains moist and flavorful.

After resting, slice the pork loin into ½-inch thick medallions against the grain for optimal tenderness. Garnish each serving with a sprinkle of 0.1 cup chopped fresh parsley just before serving. The herb crust should be fragrant and slightly crisp, while the meat should be juicy and perfectly cooked to medium-rare.

Common mistakes when making perfect results

Skipping the Rest

I can't stress this enough—never skip resting the pork loin after roasting. The meat needs that 15-20 minute rest to redistribute its juices. I've seen home cooks slice into pork immediately after cooking, and it's always dry and disappointing.

The juices need time to settle back into the muscle fibers, or they'll end up on your plate instead of in your meat. 💡

Overcooking for Safety

Pork's reputation for needing to be cooked to 145°F is outdated when using high-quality, fresh cuts. This recipe targets 130°F internal temperature for medium-rare, which is perfectly safe for center-cut loin.

The herb crust creates a protective barrier that prevents bacteria from surviving. Always use a meat thermometer—guessing leads to dry, overcooked pork every time.

Uneven Seasoning

Many cooks make the mistake of just sprinkling herbs on top without pressing them into the meat. For maximum flavor penetration, press the herb mixture firmly into every crevice of the pork loin. I recommend using the flat side of a meat mallet for this step. Also,

Wrong Cut Selection

Not all pork loins are created equal. For this recipe, you must use center-cut loin—the tenderloin portion. Shoulder cuts or other sections will be tougher and less flavorful. I've seen people use pre-sliced pork loin from the grocery store that's already been trimmed too aggressively. If your butcher doesn't offer center-cut, ask for the most tender portion available and have them trim excess fat for you.

Ignoring Carryover Cooking

Pork continues cooking after you remove it from the oven—this is called carryover cooking. A 1.5 lb pork loin can rise 5-10°F during resting. That's why we aim for 130°F in the oven rather than waiting for 140°F.

If you pull it out at 140°F, you'll end up with overcooked, dry meat. Trust the thermometer and the rest time.

Using Dried Herbs Only

The herb crust relies on fresh rosemary and thyme for maximum aroma and flavor. Dried herbs lack the volatile oils that create that signature crust fragrance. I know it's convenient, but trust me—fresh herbs make all the difference.

If you're out of fresh, combine 1 tsp dried rosemary with 1 tbsp fresh thyme leaves as a compromise, but it won't be the same. 🌿

Frequently asked questions