Chapter 27 Exercises — Sous Vide

Kitchen Labs (Full Protocols)

🍳 Kitchen Lab 27.1 — The Sous Vide Steak vs. Pan Steak

What you'll learn: That a precision water bath produces a uniform cooked-temperature gradient that no pan can match, and that the sear is a separate (and necessary) flavor step. You will also learn to look at a steak and read its temperature gradient from its color.

Time: Setup 15 minutes. Bath 1.5 hours. Sear and eat 15 minutes.

⚠️ Allergen flags: None typical. If sealing the steak with butter or compound butter, note dairy.

⚠️ Safety: Hot pan during the sear (cast iron at 220°C+ / 430°F+). Use a long-handled spatula. Have a folded towel for the pan handle. Do not seal hot food in plastic; cool to refrigerator temperature first if you're sealing leftovers.

Equipment:

• Immersion circulator (or DIY beer-cooler setup with a probe thermometer; see Chapter 27 main text)
• A 6-quart (5.7 L) container or stockpot for the bath
• 2 heavy-duty zipper-top freezer bags (gallon size), OR a vacuum sealer with appropriate bags
• 2 ribeye, strip, or sirloin steaks of the same thickness (1 to 1.5 inches / 2.5 to 4 cm), same source, same trim
• Kosher or sea salt
• Black pepper (freshly ground, optional)
• Cast-iron skillet (10–12 inch / 25–30 cm)
• High-smoke-point oil (avocado, refined peanut, ghee, or beef tallow)
• Tongs, paper towels, instant-read thermometer
• A cutting board with a juice well, a sharp knife
• A camera (phone is fine) for photographing cross-sections

Procedure:

1. Set up the bath. Fill the container with water and clip the immersion circulator to the side. Set to 54°C / 129°F. Wait until the bath reaches temperature (15–20 minutes for most home circulators).
2. Prep the first steak. Pat dry. Salt liberally on both sides. (Pepper before or after the cook is your choice; some cooks find pepper bitterness amplifies in long sous vide cooks, so they pepper after.) Place in a freezer bag or vacuum bag. If using a freezer bag, seal it most of the way, then lower it slowly into the water with the open end above the surface to push air out (the water displacement method); zip the bag the last inch just before water touches the seal.
3. Drop the bag in the bath. Make sure the steak is fully submerged. If it floats, weight it with a clean stainless spoon or a sous vide weight inside the bag.
4. Set a timer for 1 hour. A 1-inch / 2.5 cm steak needs about 45 minutes to come up to temperature plus enough hold time to fully equilibrate; 1 hour total is a reasonable target. A 1.5-inch / 4 cm steak should be 1 hour 30 minutes total.
5. At 45 minutes into the sous vide cook, prep the pan steak. Pat the second steak dry. Salt liberally on both sides. Set it on the counter to start coming to room temperature.
6. At the end of the sous vide cook, lift the bag from the bath. Open it over the sink (there will be juice). Remove the steak. Pat the surface bone-dry with paper towels. This is the single most important sear-prep step.
7. Heat the cast-iron skillet over the highest setting your stove offers. When the pan is shimmering and starting to faintly smoke (5+ minutes), add a tablespoon of high-smoke-point oil. Wait 15 seconds.
8. Sear the sous vide steak: 45 seconds per side, plus 30 seconds on each fat-cap edge if there is one. Press gently with the spatula for full contact. The steak should brown deeply in 45 seconds — if it isn't browning by then, the pan wasn't hot enough; finish the sear and acknowledge it as a lesson for next time.
9. Remove the sous vide steak. Let it rest 1 minute while you cook the second.
10. Sear the pan steak in the same pan, exactly as you'd traditionally cook a steak: 4 to 5 minutes per side for medium-rare, depending on thickness. Use an instant-read thermometer if you want to hit exactly 54°C in the center; otherwise feel for medium-rare firmness.
11. Rest the pan steak 5 minutes, the standard rest.
12. Slice both steaks across the grain into 0.5 cm slices. Photograph the cross-sections side by side.

Expected results:

• The sous vide steak shows a uniform pink/medium-rare color from edge to edge, with only a thin (millimeter-scale) browned crust. There is no gray ring.
• The pan steak shows a pronounced gradient: gray at the edge, pink at the center, with a wider browned crust.
• Both should taste delicious, but they will taste different. The sous vide steak has a more uniform texture and a "cleaner" beef flavor. The pan steak has more crust-volume and a more complex texture.

Discussion prompts:

• Which texture do you prefer? Why? What does that say about your aesthetic of "doneness"?
• Where exactly does the gray-to-pink transition begin in the pan steak? Estimate, in millimeters, the depth of the gradient. Now estimate, in degrees, how hot that gray ring got.
• If you wanted a wider browned crust on the sous vide steak, what would you change?
• A 2-inch / 5 cm steak takes about 3 hours in the bath. Why does it take 4 times longer than a 1-inch steak, not twice as long? (See Chapter 27, advanced sidebar on the heat equation.)

Classroom variant:

For Pat Hammond's AP Chemistry class: Use chicken breast instead of steak (cheaper, no rare-meat squeamishness from administrators). Run two breasts: one in a 60°C / 140°F bath for 90 minutes, one in a pot of simmering water (~95°C / 200°F) for 25 minutes. Sear neither — let the texture be the entire result. Slice both and pass around. Score on tenderness and juiciness.

🍳 Kitchen Lab 27.2 — The 63°C Egg

What you'll learn: That different proteins denature at different temperatures, and that holding an egg at exactly 63°C / 145°F produces a texture that is impossible to achieve in any other way.

Time: Setup 15 minutes. Bath 45 minutes. Plate and eat 15 minutes.

⚠️ Allergen flags: Egg.

⚠️ Safety: Use intact eggs only — discard any with visible cracks before sous vide. Do not consume eggs from cracked shells (bacterial entry risk).

Equipment:

• Immersion circulator and bath setup
• 6 large eggs (room temperature is fine; cold from fridge will need slightly more come-up time)
• A bowl of cold water for handling
• A small slotted spoon or tongs
• 6 small ramekins or shallow plates
• A ruler or straightedge for cross-sectioning yolks
• Toast or polenta for serving (optional but recommended)

Procedure:

1. Set the bath to 63°C / 145°F. Wait until stable.
2. Lower the eggs in their shells directly into the water (no bag — the shell is the container). Use a slotted spoon to lower gently; don't drop them.
3. Set a 45-minute timer. Walk away.
4. At 45 minutes, lift the eggs out with the slotted spoon. Run them under cool water for 10 seconds to cool the shell so you can handle them.
5. For each of three eggs, crack into a ramekin. Observe: the yolk should be intact and slightly mounded. The white should be runny in places, partially set in others — opaque tender, not the foamy white of a raw egg, but not the firm white of a hard-boiled egg either.
6. For the other three eggs, crack and gently break the yolk over a piece of toast. Observe: the yolk flows like a thick custard, not a runny liquid. It coats the toast.

Expected results:

• A yolk that is custard-thick — pourable but viscous, like warm honey or a thick crème anglaise.
• A white that is partially coagulated — opaque, tender, with parts that are still liquid (the more thermolabile proteins have set; the more stable ones have not).
• The combination, on toast or rice, is luxurious in a way that no other egg preparation matches.

Variations to try (separately):

• 60°C / 140°F for 45 minutes: yolk slightly less thick, white mostly liquid. Useful for sauces.
• 65°C / 149°F for 45 minutes: yolk firmer, white more set. Approaching "soft-boiled" texture but more uniform.
• 75°C / 167°F for 13 minutes: firm white, set-but-soft yolk. The "13-minute egg," another McGee favorite.

Discussion prompts:

• Why does 63°C give a texture you cannot get from boiling water?
• Different egg-white proteins (ovotransferrin, ovalbumin, ovomucoid) have different denaturation temperatures (about 60°C, 84°C, and quite high respectively). Which protein is not yet denatured in the 63°C egg? How does that show up in the texture?
• If you raised the bath to 70°C and held for the same 45 minutes, predict what you'd see. Then run the experiment.

Classroom variant:

This experiment is genuinely accessible in a classroom — it requires only a slow cooker and a thermometer. Pat Hammond runs it with two slow cookers (one at 63°C, one at 75°C) and has students predict the texture before cracking. The contrast is striking and memorable.

🍳 Kitchen Lab 27.3 — The 24-Hour Chuck Roast

What you'll learn: That long-time, low-temperature cooking can transform a tough cut into something with the texture of a steak and the flavor of a braise — a combination that no other technique produces.

Time: Active time 30 minutes (prep + sear). Bath time 24 hours.

⚠️ Allergen flags: None typical (beef).

⚠️ Safety: A 24-hour bath must be monitored. Do not leave a sous vide cook unattended overnight. If the circulator fails, the food will sit in warm-but-not-hot water — the danger zone (Chapter 35) — which is unsafe. Plan to be home or have someone check in. Do not run this experiment if you cannot maintain the bath continuously.

Equipment:

• Immersion circulator and a large container (8+ quarts / 7.5+ L) for the bath
• A 1.5–2 lb / 680–900 g chuck roast, cut from the shoulder
• Vacuum sealer with appropriate bags (a freezer bag may not seal well enough for 24 hours; vacuum is strongly preferred for long cooks)
• Kosher salt
• Black pepper, garlic, fresh thyme (optional aromatics)
• Tongs, paper towels, cast-iron skillet for the final sear
• High-smoke-point oil for the sear
• An instant-read thermometer

Procedure:

1. Salt the roast generously — about 1 teaspoon kosher salt per pound — and let it cure in the fridge, uncovered on a rack, for 4 hours minimum. (Modernist Cuisine and Kenji's Food Lab both recommend this dry-cure step for sous vide tough cuts.)
2. Pat the roast dry. Vacuum-seal with optional aromatics (a few thyme sprigs, a smashed garlic clove, fresh-cracked pepper). Use the vacuum sealer's "moist" setting if available.
3. Set the bath to 71°C / 160°F. Confirm it has reached temperature.
4. Drop the bagged roast in. Make sure it's fully submerged and won't float up against the heating element.
5. Cover the bath with plastic wrap or a fitted lid (to reduce evaporation over 24 hours). Add water to maintain level over the 24 hours.
6. Set a 24-hour timer. Be home or have someone home for the duration.
7. At 24 hours, remove the bag. Open carefully; there will be a substantial amount of meaty liquid and gelatin in the bag. Save this — it is a beautiful sauce base.
8. Pat the roast bone-dry. Heat cast iron until nearly smoking. Add a tablespoon of oil. Sear all sides for 30 seconds each — the goal is a deep brown crust, not further cooking. The interior is already at 71°C and should not get hotter.
9. Rest 5 minutes. Slice across the grain into 1 cm slices. Drizzle with the reduced bag-juice as a sauce.

Comparison cook (optional):

In parallel, run a same-sized chuck roast braised the traditional way: 1 cup of stock and 1/2 cup of red wine in a Dutch oven, lid on, 165°C / 325°F oven for 4 hours, until fork-tender. Slice and compare side-by-side with the sous vide version.

Expected results:

• The sous vide chuck has the texture of a great steak — sliceable, firm, holds its shape — but the richness of a braise (gelatin from collagen breakdown, deep flavor from concentrated juices).
• The braise is more tender (collagen has fully broken down), but the meat fibers are drier (water has been squeezed out by the higher temperature). The braise sauce is more developed because the surface caramelization from the initial sear and the slow reduction of the cooking liquid both contribute flavor that the sous vide cook doesn't develop.
• Neither is "better." They are different foods produced from the same cut.

Discussion prompts:

• The sous vide chuck has both "gelatinous" character (from collagen → gelatin) and "muscle still-firm" character (because actin hasn't denatured at 71°C). How is this possible at the same temperature? (Hint: it's a time game. Collagen needs time to break down; muscle proteins denature quickly and stop changing.)
• If you ran the same cook at 60°C for 24 hours, what would change? (Try it.)
• The bag liquid is essentially a dripping-rich beef consommé. Why is sous vide so good at producing this kind of concentrated stock?

Discussion Questions

1. Time vs. temperature. Many cooking methods couple time and temperature: longer = hotter. Sous vide decouples them. Give three examples from this chapter where the decoupling produces a result that no time-coupled method can produce.

2. Pasteurization at low temperature. Explain in your own words why a chicken breast held at 60°C for 30 minutes is as safe as one held at 73°C for one second. Reference D-values and Z-values in your answer. Cite at least one source you would consult before serving low-temperature pasteurized chicken at a dinner party.

3. The Maillard problem. Sous vide is famous for what it can do to the inside of food and infamous for what it cannot do to the outside. Why does the Maillard reaction not run in a sous vide bag, and what is the standard solution? What flavor profile is genuinely missed by sous vide-then-sear compared to a traditional grilled or roasted preparation? (Reference Chapter 8 on Maillard volatiles and Chapter 26 on grill smoke.)

4. The egg as a teaching tool. A 63°C / 145°F egg has a custard-thick yolk and a partially-set white. Identify which egg-white proteins have denatured at this temperature and which have not. What does this tell you, structurally, about how proteins respond to heat at the molecular level? (Reference Chapter 7 on protein denaturation.)

5. The thickness rule. A 1-inch / 2.5 cm steak takes ~45 minutes to reach bath temperature. A 2-inch / 5 cm steak takes ~3 hours. Why does the thickness ratio of 2× correspond to a time ratio of ~4×? Sketch the physical reasoning (heat equation, square scaling).

6. Limitations of the technique. Name three foods or preparations where sous vide is not the right tool, and explain why. (Examples might include thin cuts, foods that need a wood-smoke flavor profile, foods where crispy skin is the point.)

7. Plastics and safety. A reasonable home cook might be uncomfortable cooking food sealed in plastic for hours. Summarize the current scientific consensus on food-safe plastics at sous vide temperatures, citing at least one regulatory source (FDA, EFSA, or equivalent). What are the alternatives if a cook does not want to use plastic?

8. History of the technique. Sous vide is associated with Bruno Goussault and Georges Pralus in the 1970s. How did the technique migrate from an industrial food-service problem (Goussault's domain) to a fine-dining innovation (Pralus's domain) to a home cook's tool (Myhrvold's Modernist Cuisine and the consumer immersion circulator)? What changed — technologically and culturally — at each transition?

9. The 24-hour cook problem. A long-time, low-temperature cook (24+ hours at 60–71°C) opens up textures and conversions that no other method achieves. It also raises new safety questions and texture failure modes. Identify two specific failure modes for long cooks and how to prevent each.

10. Aging and sous vide. Danny's project found that a 35-day dry-aged ribeye is "perfect" at slightly lower temperature (53°C) than a non-aged ribeye (54°C). Speculate on why — what has aging done to the protein structure that would shift the optimal cooking temperature?

Advanced Sidebar Expanded — The Math of Pasteurization

Bacterial death follows first-order kinetics. At any given temperature, the bacterial population decreases exponentially with time. The rate of decrease at a given temperature is described by the D-value — the time required at that temperature to reduce the population by 90% (one log).

For Salmonella enterica in poultry, published D-values are approximately:

A USDA "safe" target is typically 6.5 logs of reduction (a factor of ~3 million). A more conservative restaurant target is 7 logs. Modernist Cuisine recommends 12 logs (a factor of one trillion) for the most conservative safety margin. The required time is just D × number-of-logs.

So to achieve 7 logs of Salmonella reduction:

• At 60°C / 140°F: 7 × 2.5 = ~17 minutes
• At 63°C / 145°F: 7 × 1 = ~7 minutes
• At 65°C / 149°F: 7 × 0.5 = ~3.5 minutes
• At 70°C / 158°F: 7 × 5 sec = ~35 seconds

The Z-value describes how D changes with temperature. For Salmonella, Z ≈ 5–6°C — meaning every 5°C rise in temperature reduces D (and the kill time) by a factor of 10.

Mathematically: D(T₂) = D(T₁) × 10^((T₁ – T₂)/Z)

This is why a small temperature increase from 60°C to 65°C cuts the pasteurization time from 17 minutes to 3.5 minutes — you've dropped D by a factor of 10.

⚠️ Important. These numbers are for the center of the food at that temperature for that duration. The food must reach the temperature throughout, then hold for the pasteurization time. Come-up time is in addition. For a thick chicken breast that takes 1 hour to reach 60°C, you need 1 hour come-up + 17 minutes pasteurization = 1 hour 17 minutes minimum at 60°C bath. Most published charts (Modernist Cuisine, Anova, Polyscience) build in the come-up time. Use those charts; don't try to roll your own.

For other organisms (E. coli, Listeria), the D-values and Z-values are different — sometimes more lenient, sometimes stricter. Salmonella in poultry is the most common reference case; food safety organizations also publish target reductions for Listeria in fish and ready-to-eat meats. See Chapter 35 for the broader food-safety context.

Mastery Food Checkpoint

🥖 Bread track. Sous vide is mostly orthogonal to bread — there's no sous vide baked bread. But there is a niche application: proofing. A sous vide bath set to 27°C / 80°F is a perfectly stable, draft-free, exact-temperature proof box. For sourdough or laminated doughs that prefer a particular fermentation temperature, the bath is genuinely useful. Place the dough in a covered container; float it in the bath. The temperature holds within 0.5°C, which a kitchen counter cannot match in any season.

🧀 Cheese track. Sous vide as a tool for cheese-making appears in two places. First, temperature-precise warming of milk during cheese-curd setting — some artisan cheeses call for holding milk at exactly 32°C for hours, which is impossible with a stove burner and trivial with a sous vide bath. Second, post-aged finishing of fresh cheeses (a torch sear on a sous-vide-warmed cheese plate, for instance), though this is unusual.

🍫 Chocolate track. Sous vide is the tempering bath for serious home chocolate work. We will see this in detail in Chapter 20 (already past). Tempering chocolate requires holding cocoa butter at exact specific temperatures (typically 32°C for dark, 31°C for milk) within ±0.5°C; a sous vide bath does this without strain. Some commercial chocolatiers use industrial tempering machines; sous vide is the home equivalent. Drop a bagged or jarred melted chocolate in a 32°C bath, stir gently, and the cocoa butter crystallizes into Form V (the snap-and-shine form).

🥒 Fermented vegetables track. Sous vide is mostly the wrong tool for fermentation — sealed bags are not the natural environment for fermentation, which depends on gas exchange and microbial inoculation. There are a few precision-temperature applications (holding miso at exactly 30°C for koji incubation) but the technique is not central to fermenting.

☕ Coffee track. The water-bath approach is the basis of the Specialty Coffee Association's "cup test" — coffee held at exactly 93°C / 200°F for tasting. Sous vide bath at 93°C is a cleaner way to hold cup-test water than any kettle. Also relevant for cold brew development and for the precise brewing of certain immersion-style coffees. Not central, but useful.

Sources and Further Notes

For pasteurization curves and time-temperature math, the canonical home-cook source is Douglas Baldwin's online pasteurization tables and his Practical Guide to Sous Vide Cooking (free online; Baldwin is a mathematician who has done unusually careful work on the kinetics). For the deeper reference, Modernist Cuisine Volume 2 covers temperature, safety, and pasteurization in detail. The USDA Food Safety and Inspection Service publishes guidance documents on time-temperature combinations for safe cooking; their tables for poultry and beef are the regulatory baseline in the U.S.