Sous Vide Lamb Chops: Time and Temperature

Sous vide lamb chops cook at 131°F (55°C) for medium-rare. A chop 1.25 in (3.2 cm) thick needs at least 1 hour 45 minutes, and the best window runs to 2 hours 45 minutes.

After the bath, sear the chops for about 1 minute per side.

Doneness temperatures

Medium-rare at 131°F (55°C) is the default. It is also the lowest temperature in the pasteurization tables this calculator uses. Medium at 140°F (60°C) is firmer and still juicy.

Medium-well at 150°F (65.6°C) is firm and drying out, and well done at 160°F (71.1°C) is firm and dry. Douglas Baldwin's guide gives the cause: muscle fibers shrink and lose a substantial amount of water above 140°F to 150°F (60°C to 66°C), more so as the temperature rises.

Rare at 125°F (51.7°C) is deep red and very soft. It does not pasteurize and has a time limit.

Names vary between charts. Jason Logsdon's lamb chart calls 125°F (51.7°C) rare, as the calculator does, while J. Kenji López-Alt's rack of lamb recipe counts it as the bottom of medium-rare. Choose by temperature. The doneness guide covers how to pick a setting.

Time by thickness

Measure the thickest chop through its thickest part, including any bone. Time depends on thickness, not weight.

The minimum is the time for the center to come within 1°F (0.5°C) of the bath. At 131°F (55°C) that is 50 minutes for a 0.75 in (1.9 cm) chop and 3 hours 45 minutes for a 2 in (5.1 cm) chop.

Many recipes print one range for every chop. López-Alt's recipe, for example, lists 1 to 4 hours for medium-rare. The calculator's minimum rises with thickness because heat needs longer to reach the center of a thicker piece. Baldwin's rule of thumb is that doubling the thickness increases the heating time about four fold. The calculator's own table shows a smaller step: 3 hours 45 minutes at 2 in is three times the 1 hour 15 minutes at 1 in.

The maximum is 4 hours for chops up to 1.5 in (3.8 cm) at 131°F (55°C) and above. It is a texture limit. Anova's rack of lamb guide explains that with longer cooking the muscle proteins break down and the meat turns mushy.

For 2 in (5.1 cm) chops the minimum is already close to that limit, so the maximum shown is the minimum plus 1 hour. At 131°F (55°C) that is 4 hours 45 minutes. Expect a softer texture than a thinner chop would have.

The center of a 2.5 in (6.4 cm) chop takes more than 4 hours to heat through, so the minimum shown is the pasteurization time, 6 hours. The medium-rare table marks that row with a warning.

The calculator gives the time for a thickness between the rows.

Rack vs loin chops

America's Test Kitchen describes the two cuts this way:

• Rib chops are cut from the rack, the eight ribs of the rib section. The meat sits on one side of the bone and has a fine, tender grain.
• Loin chops have a T-shaped bone through the center that separates two muscles. They are also tender.

Both are tender cuts and use the same setting. What changes the time is thickness, so a chop cut two bones thick takes longer than a single chop.

A whole, uncut rack has its own setting in the calculator and is measured across the eye of meat at its widest point, not including the bones.

Shoulder chops are not covered by these times. America's Test Kitchen notes that shoulder meat has more connective tissue and is tough unless it cooks long enough to tenderize.

How to sous vide lamb chops

1. Measure. Find the thickest chop and measure it through its thickest part, including any bone.
2. Season. López-Alt's recipe seasons the lamb generously with salt and pepper on all sides.
3. Bag. Arrange the chops in a single layer. If they overlap, measure the whole stack and use that thickness. The water displacement method seals a zipper-lock bag without a vacuum sealer.
4. Heat the bath to 131°F (55°C). Keep the bags in a single layer, fully under the water, and not overlapping. Crowded or overlapping bags heat more slowly, and the times shown will be too short for them.
5. Cook for the minimum time for your thickness.
6. Dry and sear. Take the chops out of the bag, pat them dry, and sear them as described below.

The guide on how to sous vide follows a first cook from start to finish and covers the equipment these steps assume.

Searing

Anova's guide gives the details of the sear. Heat 1 tablespoon (15 ml) of neutral oil in a cast iron or stainless steel skillet over high heat. Sear the fat side first for about 1 minute, then turn the lamb and brown the second side for about 1 minute. Add 1 tablespoon of butter, with any aromatics you like, and baste the lamb as the butter melts. The guide is written for a rack. With chops, brown the fat edge as well.

The guide advises against searing before the bath. It also says the lamb can be served straight from the pan, because meat cooked in a water bath has no temperature gradient inside to even out. The steak guide covers the same searing step for beef.

Cooking lamb chops from frozen

The last column of the medium-rare table gives the minimum time from frozen. At 131°F (55°C) it is 1 hour 15 minutes for a 0.75 in (1.9 cm) chop, 2 hours at 1 in (2.5 cm), 2 hours 45 minutes at 1.25 in (3.2 cm), and 3 hours 30 minutes at 1.5 in (3.8 cm).

At 140°F (60°C) and above, every thickness in the table is recommended from frozen.

Rare is narrower. From frozen at 125°F (51.7°C), only chops up to 1 in (2.5 cm) thick are recommended. At 1.25 in (3.2 cm) the center needs 2 hours 45 minutes to warm through, which is longer than the 2 hour 30 minute limit, so thaw the chops first or choose 131°F (55°C) or higher.

Freeze chops in a single flat layer so the thickness is the same as when thawed. The guide to cooking from frozen covers the method for other foods.

Safety

At the minimum time, a chop cooked at 131°F (55°C) is heated through but not pasteurized. That is normal for a whole, intact cut of lamb cooked to this doneness.

To pasteurize a 1.25 in (3.2 cm) chop at 131°F (55°C), cook it for at least 3 hours 30 minutes. Use that longer time, or a higher temperature, when cooking for pregnant women, children under 5, adults 65 and older, or anyone with a weakened immune system.

From frozen, a 1.25 in (3.2 cm) or 1.5 in (3.8 cm) chop at 131°F (55°C) takes longer to pasteurize than the maximum for texture. If you are cooking for anyone in those groups, choose a higher temperature.

The USDA safe minimum internal temperature for lamb is 145°F (62.8°C) followed by a 3 minute rest, as listed by FoodSafety.gov. The rare, medium-rare and medium settings are below that.

At 140°F (60°C), a chop 1 in (2.5 cm) or thicker is pasteurized at the minimum time, but only because it is held for the full time shown, so do not shorten it. At 150°F (65.6°C) and 160°F (71.1°C), chops are pasteurized at the minimum time. The article on whether sous vide is safe explains pasteurization and the limits at 130°F (54.4°C) and below.

Common problems

The edge of the chop is overcooked. The sear ran too long. The inside is already at its final temperature, so the pan only has to brown the surface. Keep it to about 1 minute per side.

The meat is soft or mushy. It stayed in the bath past the maximum. Anova's guide says lamb left for 8 hours is tender enough to pull apart with your fingers.

The fat is waxy. Anova's guide describes the fat on rare lamb that way. Sear the fat side and the fat edge until browned, or cook at 131°F (55°C) or 140°F (60°C). Duck breast also carries a layer of fat under its skin, and its guide covers rendering that fat in the pan.