Sous Vide Pork Loin: Time by Diameter and Temperature

Sous vide pork loin cooks at 140°F (60°C) for a medium roast that is pale pink, tender and juicy. A roast 3.5 in (8.9 cm) in diameter needs at least 6 hr in the bath, is at its best between 6 hr and 7 hr, and should come out by 7 hr.

The time depends on the diameter of the roast, not on its weight or length. Every time on this page comes from the calculator.

Pork loin temperature and doneness

The bath temperature sets the doneness. The roast heats to the temperature of the water and stops there.

The default is 140°F (60°C). Choose 150°F (65.6°C) if you want no pink and accept a firmer roast that is starting to dry. At 160°F (71.1°C) the roast is white, firm and a little dry. The 135°F (57.2°C) setting gives a rosy pink, softer roast, but it has the longest times and a lower limit on diameter, covered below.

The drying at the two higher settings comes from water loss. Douglas Baldwin's guide to sous vide cooking explains that above 140 to 150°F (60 to 66°C) muscle fibers shrink along their length and lose a substantial amount of water.

The pork temperature chart puts the loin next to the other pork cuts.

How long to sous vide pork loin, by diameter

A boneless loin roast is close to a cylinder, and the calculator times it as one. The thickness you enter is the diameter: measure straight through the center of the roast at its thickest point.

Many loin roasts are oval, wider than they are tall. Enter the smaller dimension only if the other is no more than one and a half times as large. Otherwise treat the roast as a flat piece and use the pork chops setting with its thickness.

Length and weight do not change the time. Heat reaches the center from the sides, so a long roast and a short roast of the same diameter take the same time.

The minimum is the longer of two times: the time for the center to come within 1°F (0.5°C) of the bath, and the time to pasteurize a roast of that diameter. At 140°F (60°C) the center of a 3.5 in roast reaches the bath temperature at 5 hr 30 min, and the roast is pasteurized after 6 hr, so the minimum is 6 hr.

These minimums are longer than in recipes that only heat the meat through, because they are the time for the center of a roast this thick to pasteurize. Jason Logsdon of Amazing Food Made Easy gives 3 to 5 hours at 140°F (60°C) as usual in his pork loin roast guide. The calculator agrees with that range for roasts 2.5 to 3 in (6.4 to 7.6 cm) across, which need 3 hr 45 min and 4 hr 45 min. A 2 in (5.1 cm) roast needs 2 hr 45 min, and wider roasts need more.

A 2 in roast has the usual 4 hr maximum. From 2.5 in up, every minimum in this table is close to or past the usual 4 hr texture limit for tender cuts, so the calculator sets the maximum at the minimum plus 1 hr. Expect a softer texture than a thinner piece would have.

Medium-well pork loin

At 150°F (65.6°C) pasteurization is faster, so the minimums are a little shorter: 3 hr for 2.5 in, 4 hr 15 min for 3 in and 5 hr 30 min for 3.5 in. At 160°F (71.1°C) the times are 3 hr 15 min, 4 hr 15 min and 5 hr 30 min.

Medium-rare pork loin

At 135°F (57.2°C) a 2.5 in roast needs 4 hr 30 min, a 3 in roast needs 6 hr and a 3.5 in roast needs 7 hr 15 min.

Roasts wider than 3.75 in

A loin thicker than 3.75 in (9.5 cm) is outside the range of the published tables. Cut it in half lengthwise so each piece is thinner, then measure the thickest part of each piece.

You can also slice the roast into thick chops before cooking. They cook as flat slabs, and the pork chops guide has those times.

Pork loin vs pork tenderloin

The National Pork Board places the loin roast between the shoulder and the beginning of the leg. It is sold bone-in or boneless and typically weighs 2 to 4 pounds, against about 1 pound for a tenderloin. The times on this page are for a boneless roast.

Food Network's comparison describes the loin as a wide cut of 2 to 5 pounds covered in a layer of fat, and the tenderloin as a long, lean cut that runs along the backbone.

In the bath the difference is time. A tenderloin 2 in (5.1 cm) across needs 2 hr 45 min at 140°F (60°C), which is less than half the time of a 3.5 in loin. The pork tenderloin guide has the full table for that cut.

The Pork Board says a loin roast should not be braised or stewed, because it tends to fall apart and turn a bit tough in moist heat. The pork shoulder guide covers the cut that takes a long tenderizing cook of 8 to 36 hours.

How to sous vide a pork loin roast

1. Heat the bath. Set it to 140°F (60°C), or to the temperature you chose above.
2. Season. Salt and pepper on all sides. The Pork Board lists brining and spice rubs as good options for this cut.
3. Bag it. Use a vacuum sealer, or a large zipper-lock bag sealed with the water displacement method.
4. Cook for the time that matches the diameter. Keep the bag fully under the water for the whole cook. With more than one roast, keep the bags in a single layer and not overlapping. Crowded or overlapping bags heat more slowly, and the times shown will be too short for them.
5. Dry it. Take the roast out of the bag and pat it dry with paper towels.
6. Sear. Baldwin's guide sears with a blowtorch or in a heavy skillet with oil that is just smoking. Turn the roast so every side browns, including the fat side.
7. Slice and serve.

The sear is there because the bath cannot brown anything. Baldwin's guide says the browning reaction becomes noticeable around 265°F (129°C) and gives good browning around 300°F (149°C), far above any bath temperature.

Cooking pork loin from frozen

A frozen loin heats slowly, and wide roasts run into the safety limit. At 140°F (60°C) a frozen 2.5 in roast needs at least 6 hr 45 min and a frozen 3 in roast needs 9 hr.

The same warning applies at 135°F (57.2°C) to frozen roasts wider than 2.5 in, and at 150°F (65.6°C) to a frozen 3.75 in roast. A not recommended result does not count as pasteurized, whatever time it shows.

The frozen heat-through time is 1.55 times the thawed time, and the pasteurization time is longer by a matching allowance. That allowance is this calculator's own rule, because no published table covers pasteurizing from frozen. The guide to cooking from frozen explains the method for other foods.

Is pork loin safe at 140°F?

The USDA safe minimum internal temperature for pork roasts is 145°F (62.8°C) followed by a 3 minute rest, as listed on FoodSafety.gov.

The 135°F (57.2°C) and 140°F (60°C) settings are below that. These lower temperatures pasteurize the roast only because it is held for the full minimum time shown, so do not shorten it.

The maximum is a texture limit. The roast is pasteurized at the minimum time, and extra time at 131°F (55°C) and above makes it softer but does not make it unsafe.

Pink color alone does not show that pork is undercooked. The USDA Food Safety and Inspection Service states that cooked pork can be pink in the center even when it has reached a safe internal temperature.

The 6 hour limit in the warnings above comes from Baldwin's guide, which says the center of the food should reach 130°F (54.4°C) within 6 hours. The sous vide safety guide explains how time and temperature work together.

Common problems

The roast is dry. The bath was too hot for the texture you wanted. The 150°F (65.6°C) setting is firm and starting to dry, and 160°F (71.1°C) is a little dry. Drop to 140°F (60°C).

The texture is softer than expected. A wide roast spends more than 4 hr in the bath before it is done, and meat keeps softening over that time. A narrower roast, or a wide one cut in half lengthwise, has a shorter minimum.

The roast does not fit the bag or the pot. Cut it in half across its length. The diameter stays the same, so the time does not change.

If you cook a roast ahead and slice it over several days, the meal prep guide covers chilling and reheating it.