The Complete Guide to Sous Vide Time and Temperature
Sous vide cooking looks deceptively simple: seal food in a bag, drop it in a precisely heated water bath, and wait. But the two numbers that decide whether dinner is sublime or unsafe — time and temperature — are governed by real thermal physics. This guide explains exactly how a sous vide time and temperature calculator works, why thickness matters more than weight, how shape changes everything, and when "cooked through" is not the same as "safe to eat." Every number in the SousLine planner above is computed from the published tables of Dr. Douglas Baldwin's A Practical Guide to Sous Vide Cooking, the reference that professional kitchens and food-safety researchers have trusted for over fifteen years.
Why Thickness — Not Weight — Controls Sous Vide Time
Ask ten home cooks how long to sous vide a steak and nine will answer with a weight: "it's a 300-gram steak." That number is almost useless. Heat travels by conduction from the surface to the geometric center of the food, and the distance it must travel is half the thickness. Double the thickness of a steak and you do not double the cooking time — you roughly quadruple it. A 25 mm steak reaches temperature in about 1¼ hours as a slab; the same cut at 50 mm needs about 3½ hours. Weight tells you nothing about this; a long flat 300-gram fillet and a short fat 300-gram chunk behave completely differently in the bath.
This is why every serious sous vide thickness chart — including Baldwin's Table 2.2 — is organized by millimeters, not grams. The practical takeaway: always measure the thickest point of your sealed pouch with a ruler, and plan from that number. If you are cooking several pieces, the thickest one sets the schedule for the whole bath.
Shape Matters: Slab, Cylinder and Sphere Heat Differently
Most online calculators ask only for thickness and quietly assume your food is a flat slab. That assumption can be badly wrong. Heat enters from every exposed surface, so a cylinder (a rolled roulade, a sausage, a beef tenderloin) and a sphere (a meatball, a whole tied roast) reach core temperature much faster than a slab of the same thickness — heat converges on the center from more directions at once.
Baldwin formalized this with a geometric factor: a large flat slab is the slowest shape, a long cylinder heats roughly 40–50% faster, and a sphere is faster still. The numbers are striking. A 40 mm slab needs about 2½ hours to come within half a degree of the bath; the same 40 mm as a cylinder needs only about 1¼ hours, and as a sphere under an hour. SousLine is shape-aware: pick the geometry closest to your cut and the heat-through time is interpolated from the matching column of the published tables instead of a one-size-fits-all guess.
One caveat the tables themselves carry: they assume pouches do not touch or overlap and stay fully submerged. Crowded bags insulate each other and every published time underestimates reality. Give each pouch its own water contact.
Heat-Through vs. Pasteurization: Two Different Finish Lines
Here is the distinction that separates a decent sous vide time and temperature calculator from a dangerous one. "Heat-through" means the core has reached the bath temperature — the steak is medium-rare edge to edge. "Pasteurization" means the food has additionally been held at temperature long enough to destroy pathogens. The two finish lines are hours apart at low temperatures.
Food-safety experts target a million-to-one reduction in Listeria, a ten-million-to-one reduction in Salmonella, and a hundred-thousand-to-one reduction in E. coli. Because bacteria die faster as temperature rises, the required sous vide pasteurization time collapses with heat: beef at 55 °C (131 °F) needs roughly 2¾ hours at 25 mm, but the same cut at 60 °C (140 °F) needs only about 1½ hours. Baldwin computed these worst-case times numerically from measured D-values (the minutes needed to kill 90% of a pathogen at a reference temperature) and z-values (how fast lethality scales with temperature), so you never have to do the microbiology yourself.
The planner above shows both numbers separately: the heat-through time and the hold — the extra minutes after the core arrives during which pathogens are actually being destroyed. Watching the hold shrink as you nudge the bath temperature up is the single best intuition-builder in sous vide safety.
The 54.4 °C Floor: When Pasteurization Is Not Practical
Baldwin's pasteurization tables start at 54.4 °C (130 °F), and that is not an accident. Below about 52–54 °C, pathogens such as Clostridium perfringens can still grow, and the holding times needed for a safe kill stretch into impractical territory. If your doneness preset sits below the floor — a 50 °C rare steak or 42 °C rare salmon — SousLine will tell you plainly: pasteurization is not on the table. That food must be served within four hours and must never be cook-chilled for later. This is not the tool being cautious; it is the physics being honest.
Cooking From Frozen: The Honest Adjustment
Yes, you can cook sous vide straight from frozen — one of the method's genuine superpowers. But frozen food carries the latent heat of thawing: melting ice inside the meat absorbs a large amount of energy before the temperature can even begin to climb. Baldwin's Table 2.3 quantifies it: a 25 mm slab that heats through in 1¼ hours thawed needs about 1¾ hours from frozen; a 50 mm slab jumps from 3½ to over 5 hours.
For pasteurization, no frozen tables were ever published, so SousLine applies the standard conservative correction used by working chefs: it adds the frozen-vs-thawed heat-through delta to the tabulated pasteurization total. The hold phase itself does not change — once the core is hot, ice is irrelevant — only the journey there gets longer. Toggle "Frozen" in the planner and watch both readouts move.
Cook-Chill: The Ice Bath Is Not Optional
Cooking kills active bacteria, but it does not kill spores. When pasteurized food cools slowly through the danger zone, surviving spores of Clostridium can germinate and multiply. Baldwin's answer is Table 1.1: the sealed pouch must go into ice water that is at least half ice until the core reaches 5 °C (41 °F), and the time depends — again — on thickness and shape. A 50 mm slab needs nearly 3 hours of ice bath; the same thickness as a sphere needs about 1 hour.
Only then may the food be refrigerated (a few days) or frozen (up to a year). The planner's cook-chill readout gives you that ice-bath time, and the built-in chill timer counts it down with an audible alert so you do not have to babysit the clock. Never cool pasteurized food on the counter "for a bit first" — the spore clock starts the moment the pouch leaves the bath.
Sequencing a Whole Dinner in One Bath
The feature SousLine owners reach for most is the bath sequencer. A real dinner is never one steak: it is chicken thighs at 74 °C, a medium-rare strip at 55 °C, and salmon somebody requested at 50 °C, all meant to land on the table at 7:30 PM. Because every protein has a different total bath time, the trick is to work backwards — drop the longest cook first and stagger the rest.
Add each item, set your serve time, and the sequencer outputs a drop-in schedule ordered by start time, with clock times you can set phone alarms to. It also flags temperature conflicts: items more than about 1.5 °C apart cannot share a bath, so the schedule tells you honestly when you need a second circulator (or a cooler with hot water as a holding bath). Plan once, drop on schedule, sear everything at the end.
Temperature Quick Reference
These are the doneness anchors built into the planner's presets, drawn from Baldwin's Table 2.1 and widely used restaurant practice:
| Protein | Rare | Medium-rare | Medium | Well |
|---|---|---|---|---|
| Beef / lamb | 50–52 °C | 55 °C | 60 °C | 71 °C |
| Pork | — | 58 °C | 61 °C | 71 °C |
| Chicken breast | — | — | 60–63 °C* | 74 °C |
| Chicken thigh | — | — | 65 °C* | 74–82 °C |
| Lean fish | 45 °C | 50 °C | 55–60 °C | — |
| Fatty fish (salmon) | 42 °C | 50 °C | 60 °C | — |
* Poultry below 74 °C is safe ONLY when pasteurized for the full tabulated time — never shortcut the hold.
Why We Built on Baldwin's Tables
Dozens of sous vide charts circulate online, many copied from each other with the provenance sanded off. Douglas Baldwin's A Practical Guide to Sous Vide Cooking is different: every table is derived from the heat equation and published pathogen-kill kinetics, with the assumptions printed alongside the numbers. Tables 2.2 and 2.3 give heat-through times by thickness and shape; Tables 3.1, 4.1 and 5.1 give pasteurization totals for fish, poultry and meat; Table 1.1 gives ice-water cooling times. SousLine bakes these tables in and interpolates between the published points, credits the source on every readout, and flags clearly the two places where we extend beyond the printed page: fish pasteurization (computed from Baldwin's published Table 3.1 model parameters) and the frozen pasteurization delta (a conservative, documented approximation). When a number matters for safety, you deserve to know exactly where it came from.
A Final Word on Safety
Sous vide is extraordinarily safe when the tables are respected — and unforgiving when they are improvised. Keep baths at or above 54.4 °C for any cook longer than four hours, never stack or overlap pouches, chill rapidly in real ice water before storing, and treat every sub-pasteurization cook as serve-immediately food. The planner does the arithmetic; your thermometer, your ice, and your judgment do the rest.