How Long to Slow Roast a Pork Loin for Perfectly Juicy Meat

Slow roasting a pork loin is a great way to end up with incredibly tender, juicy and flavorful meat. But getting the timing right is crucial – overcook it and you’ll dry it out, undercook and it will be tough. This guide will walk through everything you need to know for roasting pork loin low and slow to perfection.

Why Slow Roast Pork Loin?

Compared to quicker, high heat cooking methods like grilling or pan frying slow roasting pork loin has some major advantages

• It tenderizes the meat by gently breaking down the collagen and connective tissue over time, resulting in very moist, fork-tender pork

• The low oven temperature gives the pork time to soak up flavors from any rubs, marinades or aromatics This develops a richer, more complex taste

• Slow roasting renders excess fat slowly so the end result isn’t greasy.

• It’s an extremely forgiving cooking method. The oven provides consistent, gentle heat so the pork has room for error if cook times vary slightly.

• Simply season the pork, pop it in the oven, and let it do its thing with minimal monitoring required.

How Long Does Pork Loin Take to Roast?

The exact time needed to slow roast pork loin depends on a few factors:

1. Weight

• A 1-1.5 lb pork loin roast takes about 2 hours to slow roast.

• A 2-3 lb roast takes approximately 3 hours.

• Larger 3-5 lb roasts need 4+ hours.

As a general rule of thumb, estimate 15-20 minutes per pound at 300°F.

2. Roast Shape

• A shorter, more compact loin roast will cook faster than a longer, thinner one.

• Try to choose a evenly shaped roast for the most even cooking.

3. Bone-In or Boneless

• Bone-in pork loin takes slightly longer since the bones insulate the meat.

• Plan for 15-30 minutes extra time for bone-in compared to boneless.

4. Browning Time

• If searing or browning the pork before roasting, the browning time should not be included in the total roast time.

• For example, a 3 lb roast needs about 3 hours to roast, plus another 5-10 minutes for browning.

How to Tell When Pork Loin is Done

Since pork needs to be fully cooked to 145°F for food safety, using an instant read thermometer is the only surefire way to test doneness.

Aim to remove pork loin from the oven when it registers:

• 140-145°F for slightly pink meat.

• 150-155°F for fully cooked, throughly pink-free meat.

The temperature will continue rising 5-10 degrees after removing from the oven.

If you don’t have a thermometer, check for these visual cues:

• The meat should have a light brown, roasted color on the outside.

• Prick it with a fork – properly roasted loin will be fairly firm but fork-tender.

• Clear juices will run from the pork, rather than pink or red juices.

Step-By-Step Guide for Roasting Pork Loin

Follow these simple steps for perfect oven roasted pork loin every time:

1. Prep the Pork Loin

• Choose a 1.5-3 lb boneless or bone-in pork loin roast.

• Thoroughly pat dry with paper towels. Dry exterior = better browning.

• Trim off any excess fat or silver skin. Leave about a 1/4 inch fat cap.

• Score the fat cap by slicing cross-hatch marks into it. This helps render fat.

2. Season the Roast

• Generously season all over with salt, pepper and any other spices or herbs.

• For extra flavor, coat with a mustard-herb mixture up to 24 hours before roasting.

• Rub the seasoning over entire roast so it’s evenly distributed.

3. Brown the Pork Loin (Optional)

• In a skillet, sear all sides of pork loin over high heat until a nice brown crust forms, about 1-2 minutes per side.

• Skipping this step is fine if short on time, but browning adds richer flavor.

4. Roast in the Oven

• Place loin fat side up on a metal roasting rack set inside a sheet pan. The rack prevents steaming.

• Insert an oven-safe meat thermometer into the center of the roast, avoiding bone or fat.

• Roast in a 300°F oven until the thermometer reads 140-145°F. For a 2-3 lb roast, this takes roughly 2.5-3 hours.

• Let rest 10-15 minutes before slicing into juicy pork loin perfection!

Flavorful Pork Loin Roast Recipes

Beyond just salt and pepper, marinating or seasoning the pork loin can take it to the next level. Consider one of these full-flavored roast recipes:

Simple Brown Sugar Pork Loin

Coat the pork loin with a mix of brown sugar, salt, garlic and onion powders, then slow roast with carrots until caramelized and tender.

Mustard Crusted Pork Roast

A zesty Dijon mustard, thyme and rosemary mixture gives incredible flavor to the crunchy, crusted exterior.

Orange Ginger Pork Loin

For a tasty twist, marinate the pork overnight in fresh orange juice, ginger, honey and soy sauce before roasting.

Mediterranean Herb Stuffed Pork Loin

Butterfly the loin, stuff with a blend of sun-dried tomatoes, feta, basil and parsley, then roll and truss.

Serving Suggestions for Pork Loin Roast

Slice up the rested pork loin and serve it with:

• A pan sauce made from the flavorful roasted pan drippings.

• Sauteed vegetables like green beans, brussels sprouts or asparagus.

• Roasted potatoes or sweet potatoes.

• A fresh salad or slaw.

• Rice, couscous or quinoa.

Get creative with toppings like chimichurri, salsa verde, chutneys or fall fruit compotes too.

Pork Loin Roast FAQs

Is it better to cook pork loin at a high or low temperature?

Low and slow is best, ideally 300°F or lower. High heat risks drying out the lean meat.

Can you slow cook pork loin in an oven?

Yes, use 300°F and roast until it reaches the 140-145°F internal temperature for perfectly cooked pork.

Should pork loin roast be covered while cooking?

No, leave it uncovered in the oven so the exterior can brown. Covering will steam the meat.

The Takeaway on Slow Roast Pork Loin

When slow roasted at a low oven temp, pork loin transforms from tough into fork-tender perfection. For the ideal texture and juiciness, cook it until the internal temperature hits 140-145°F. With the simple roasting method and timing guidelines above, you’ll end up with a beautiful, flavorful main dish roast.